Loss of Crew
+ Crew Injury
System Issue
Operational Issue
Early Termination
0
#
0
%
15
4
14
3
57
13
43
10
429 total spacewalks through 1/25/2020.
94 (22%) experienced significant incidents and/or close calls.
All hours represent EVA hours, not crew member hours.
United States
Russia
China
Voskhod 2
3/18/1965
Gemini 4
6/3/1965
Gemini 9
6/5/1966
+
Gemini 10, EVA 1
7/19/1966
+
Gemini 10, EVA 2
7/20/1966
Gemini 11, EVA 1
9/13/1966
Apollo 11, EVA 1
7/20/1969
Apollo 12, EVA 2
11/2/1969
Apollo 15, EVA 2
7/31/1971
Apollo 15, EVA 3
8/1/1971
Apollo 16, EVA 1
4/21/1972
Apollo 16, EVA 2
4/22/1972
Apollo 16, EVA 3
4/23/1972
Apollo 17, EVA 1
12/11/1972
+
Skylab 2, EVA 2
6/7/1973
Skylab 3, EVA 3
9/22/1973
Skylab 4, EVA 1
11/22/1973
Skylab 4, EVA 2
12/25/1973
Skylab 4, EVA 3
12/29/1973
Skylab 4, EVA 4
2/3/1974
Salyut 6 PE-1, EVA 1
12/20/1977
Salyut 6 PE-3, EVA 1
8/15/1979
Salyut 7 PE-1, EVA 1
7/30/1982
+
STS-41B, EVA 1
2/7/1984
STS-41C, EVA 1
4/8/1984
STS-41C, EVA 2
4/11/1984
Salyut 7 PE-3, EVA 6
8/8/1984
+
STS-51D
4/16/1985
STS-51I, EVA 2
9/1/1985
Mir, PE-2, EVA 1
4/11/1987
Mir, PE-6, EVA 1
7/17/1990
Mir, PE-8, EVA 3
1/26/1991
STS-37, EVA 1
4/7/1991
+
STS-37, EVA 2
4/8/1991
Mir, PE-9, EVA 6
7/27/1991
+
Mir, PE-10, EVA 1
12/20/1992
Mir, PE-13, EVA 1
4/19/1993
STS-57, EVA 1
6/25/1993
Mir, PE-14, EVA 3
9/28/1993
Mir, PE-14, EVA 4
10/22/1993
STS-61, EVA 2
12/5/1993
STS-63, EVA 2
2/9/1995
+
STS-80, EVA 1
11/29/1996
STS-86, EVA 1
10/1/1997
STS-88, EVA 1
12/7/1998
STS-96/2A.1
5/27-6/6/1999
STS-97/4A, EVA 1
12/3/2000
+
STS-98/5A, EVA 1
2/10/2001
STS-98, EVA 2
2/12/2001
+
STS-100/6A, EVA 2
4/22/2001
+
STS-100/6A, EVA 3
4/24/2001
+
ISS Exp-9 U.S. EVA Ops
5/19/2004
RS EVA 9A
6/24/2004
RS EVA 10
8/3/2004
RS EVA 13
3/28/2005
STS-121/ULF1.1, EVA 2
7/10/2006
STS-116/12A., EVA 1
12/12/2006
STS-118/13A.1, EVA 3
8/15/2007
STS-120/10A, EVA 3
10/30/2007
RS EVA 20A
7/10/2008
STS-126/ULF2, EVA 2
11/20/2009
STS-126/ULF2, EVA 4
11/24/2008
RS EVA 21A
3/10/2009
STS-125HST, EVA 4
5/17/2009
STS-127/21A, EVA 3
7/22/2009
STS-128/17A, EVA 3
9/5/2009
STS-130/20A, EVA 1
2/1/2010
STS-130/20A, EVA 2
2/14/2010
STS-130/20A, EVA 3
2/17/2010
U.S. EVA 15
8/7/2010
U.S. EVA 16
8/11/2010
STS-134/ULF6, EVA 1
5/20/2011
STS-134/ULF6, EVA 3
5/25/2011
+
U.S. EVA 18
8/30/2012
U.S. EVA 22
7/9/2013
U.S. EVA 23
7/16/2013
U.S. EVA 24
12/21/2013
U.S. EVA 25
12/24/2013
U.S. EVA 32
10/28/2015
U.S. EVA 35
1/15/2016
U.S. EVA 38
1/6/2017
U.S. EVA 41
3/30/2017
U.S. EVA 42
5/12/2017
U.S. EVA 46
10/20/2017
U.S. EVA 53
3/29/2019
U.S. EVA 62
1/15/2020
U.S. EVA 62
1/15/2020
+
U.S. EVA 63
1/20/2020
+
U.S. EVA 64
1/25/2020
Apollo 12 | 11/2/1969 | EVA: 2
During the November 19th EVA, the crew members reported that the Extravehicular Mobility Unit’s (EMU or EVA suit) integrated thermal meteoroid garments were severely worn by the abrasive nature of the lunar dust. During the ascent to lunar orbit, the dust that was tracked into the Lunar Excursion Module became weightless, causing the crew members to experience difficulty breathing and requiring them to put on their helmets.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
James R. Gaier, The Effects of Lunar Dust on EVA Systems During the Apollo Missions
Apollo 11 | 7/20/1966 | EVA: 1
While egressing the Lunar Excursion Module (LEM), one of the crew members experienced difficulty crawling through the hatch due to tight clearances between the LEM hatch and the Portable Life Support System attached to the back of the suit.
Source(s):
Gemini 11 | 9/13/1966 | EVA: 1
During preparation for the September 13th EVA, the crew member that would be performing the spacewalk became overheated in the suit prior to egressing the capsule. Difficulty attaching the helmet visor contributed to the exertion and overheating. Because the life support oxygen cooling system heat exchanger could only operate in a vacuum, the crew member was not able to receive cooling from it. The EVA proceeded, but the crew member that remained in the capsule during the EVA brought the spacewalking crew member in early, noting that the crew member was sweating and not able to see well.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 10 | 7/20/1966 | EVA: 2
While moving over to the Agena docking target, the EVA crew member dislodged a sharp-edged electrical discharge ring that had the potential to damage the suit or its umbilical. After returning to the Gemini capsule, the EVA umbilical blocked one of the crew members from seeing the control panel, preventing the crew member from reporting the status of fuel to ground control. The difficulty that the crew members had with the umbilical also led to the radio accidentally being shut off for a brief time.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 10 | 7/19/1966 | EVA: 1
While executing the July 19th EVA, the crew member conducting the spacewalk experienced eye irritations causing the EVA to be terminated early. The cause of the irritation was traced to lithium hydroxide used for carbon dioxide absorption leaking into the helmet when both suit fans were operating simultaneously.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 9 | 6/5/1966
During the June 5th EVA, the crew member conducting the spacewalk experienced difficulty maneuvering around the outside of the capsule. While moving around during the EVA, the crew member’s suit became damaged, resulting in the crew member having thermal burns on his back from the sunlight striking the torn areas of the suit. The workload that the crew member experienced also exceeded the cooling capacity of the suit.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 4 | 6/3/1965
On June 3rd 1965 the crew of Gemini 4 experienced difficulty closing the capsule hatch after completion of the EVA. The crew was finally able to get the hatch closed when one crew member pulled on the other crew member while turning the hatch handle. While struggling to close the hatch, the crew member performing the spacewalk exerted himself beyond the cooling capacity of the suit, leading to slight fogging of the helmet visor.
Source(s):
http://www.astronautix.com/g/gemini4.html
David F. Portree and Robert Trevino, Walking to Olympus
Voskhod 2 | 3/18/1965
During the March 18th 1965 EVA, the spacesuit the crew member was wearing while performing the EVA ballooned, causing an increase in the suit’s stiffness. After completing the EVA, the crew member entered the airlock head first and discovered that the suit would not bend enough to allow him to turn around and close the hatch. The crew member was forced to lower the pressure inside the suit, risking the potential onset of dysbarism (“the bends”). The struggle to enter and seal the airlock led to the crew member overheating, nearly to the point of heatstroke, due to the workload exceeding the cooling capacity of the early EVA suit.
Source(s):
http://www.astronautix.com/v/voskhod2.html
Salyut 6 PE-3 | 8/15/1979 | EVA: 1
After performing the EVA on August 15th, one of the crew members noticed a small puncture in the suit’s pressure bladder. The cause of the puncture was possibly a sharp wire on the KRT-10 antenna that the crew members removed from the Salyut 6 station.
Source(s):
Salyut 6 PE | 12/20/1977 | EVA: 1
On December 20th while performing an EVA from the Salyut 6 docking port, one crew member partially left the docking port without attaching the safety tether. While the crew member was untethered, the suit umbilical was still attached and prevented him from accidentally floating free of the station.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 2/3/1974 | EVA: 4
While performing the February 3rd EVA, one crew member’s suit cooling system developed a leak similar to the one experienced on EVA 2. The crew member switched to minimum cooling, minimizing the amount of cooling water leaking, and completed the tasks assigned for the EVA. A later investigation determined that the probable cause of the leaking was due to the connectors being exposed to the cold environment of space and a small side load being placed on the connector.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 12/29/1973 | EVA: 3
During the December 29th EVA, a cooling water leak caused ice to form on the front of one crew member’s suit. A later investigation determined that the probable cause of the leaking was due to the connectors being exposed to the cold environment of space and a small side load being placed on the connector.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 12/25/1973 | EVA: 2
During the December 25th EVA, a cooling water leak caused yellow ice to form on the front of one crew member’s belly-mounted pressure control unit. The color of the ice indicated that the leak was from one of the two water connectors (quick disconnects) of the composite connector at the interface of the life support umbilical/pressure control unit. The leak was too small to fully deplete the cooling water supply. A spare unit was used on subsequent EVAs. A later investigation determined that the probable cause of the leaking was due to the connectors being exposed to the cold environment of space and a small side load being placed on the connector.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 11/22/1973 | EVA: 1
During the November 22nd EVA, the crew members experienced difficulty keeping their suit umbilicals separated. This cost them time and effort to keep the umbilicals under control and could have presented a risk of severe entanglement.
Source(s):
Skylab 3 | 9/22/1973 | EVA: 3
During the September 22nd EVA, the airlock module suit cooling system suffered leaks and was inoperable for the EVA. The physically undemanding nature of the tasks to be completed allowed the EVA to proceed with only air cooling.
Source(s):
Skylab 2 | 6/7/1973 | EVA: 2
During the June 7th EVA, the Skylab primary EVA heat exchanger module suffered from minor clogging, but the EVA was able to continue. The clogging of the heat exchanger led engineers to design a new module that would serve as a backup. The new backup module was delivered to Skylab in July 1973 by the next crew.
Source(s):
Apollo 17 | 12/11/1972 | EVA: 1
During the December 11th EVA, one of the crew members suffered contusions to his hand while extracting a core sample. The device used to obtain the core samples became stuck, despite a design that was supposed to ease removal of the core sample. During the EVA, part of the Lunar Rover fender was broken off, but taped back in position. On the way to the first geological survey station the “repaired” fender fell off and showered the crew members with dust.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 16 | 4/23/1972 | EVA: 3
During the EVA on April 23rd, the Lunar Rover suffered a temporary navigational computer failure. The crew members used the sun’s position to determine their location, allowing them to locate the Lunar Excursion Module. An investigation later revealed that the most probable cause of the issues with the navigation system was improper wire crimps on the flight vehicle when compared with the solder connections used in the test vehicle on the ground. The improper crimps allowed the wires to loosen when exposed to cold temperatures, causing loose connections.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 16 | 4/22/1972 | EVA: 2
During the EVA on April 22nd one crew member’s Portable Life Support System radio antenna struck the Lunar Excursion Module’s hatch frame, breaking off a portion of the antenna. The damage to the antenna caused a small drop in signal strength, but the EVA was allowed to continue.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 16 | 4/21/1972 | EVA: 1
During the April 21st EVA, one of the crew members tripped over the heat flow sensor cable connected to the Apollo Lunar Surface Experiments Package (ALSEP), tearing it loose. Mission control elected not to repair the cable on the subsequent EVA due to concern that the repair would take too much time and could possibly short-circuit the ALSEP.
One of the crew members attempted to jump and salute the flag they had placed, but slipped and fell onto the Portable Life Support System (PLSS). However, no significant damage was done to the PLSS, which remained operational.
After ingressing the Lunar Excursion Module, the crew members reported the same problems that previous flights had with the lunar dust – stuck zippers and disconnects, and scratched indicators that were difficult to read.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 15 | 8/1/1971 | EVA: 3
During the August 1st EVA, the vertical Portable Life Support System (PLSS) radio antenna snapped off of one crew member’s PLSS. The other crew member taped it back into a horizontal position. While navigating back to the Lunar Excursion Module (LEM), the crew members experienced difficulty navigating until they encountered their outbound tracks, which led them back to the LEM. An investigation later revealed that the most probable cause of the issues with the navigation system was improper wire crimps on the flight vehicle when compared with the solder connections used in the test vehicle on the ground. The improper crimps allowed the wires to loosen when exposed to cold temperatures, causing loose connections.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 15 | 7/31/1971 | EVA: 2
During the July 31st EVA, while driving the Lunar Roving Vehicle, the front steering failed. The crew member driving was able to steer the rover with only the rear steering. Also during the EVA, one of the crew members’ drink bags failed to operate, causing the crew member to become dehydrated. After completing the EVA, the crew members discovered that the abrasive lunar dust made the Portable Life Support System (PLSS) connectors tight and difficult to operate. In addition, the crew members also experienced pain in their fingers caused by their fingernails pressing against their glove fingertips.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Mir, PE-2 | 4/11/1987 | EVA: 1
During the April 11th EVA, the Russian Orlan-DM spacesuit in use by one of the crew members experienced a minor pressure drop. The cause of the pressure drop was quickly determined to be an incorrect switch position, which was corrected, allowing the EVA to continue.
Source(s):
STS-51I | 9/1/1985 | EVA: 2
During the September 1st EVA when the EVA crew members were handling a satellite from opposite sides, a lack of sight between them hindered visual cues and posed a potential threat of collision with Space Shuttle Discovery. The lack of visual cues caused the EVA crew members to impart opposite motions into the satellite.
Also during the EVA, one of the EVA crew members became very cold and shut off water flow to his Liquid Cooling and Ventilation Garment. With the water flow turned off, the crew member’s Extravehicular Mobility Unit (EMU or spacesuit) helmet began to fog.
Prior to the EVA the lithium hydroxide canisters used during the previous EVA to scrub carbon dioxide from the EMU were inadvertently placed back into the EMUs instead of being changed for new canisters.
Source(s):
Salyut 7 PE-3 | 8/8/1984 | EVA: 6
During the August 8th EVA, one of the Russian Orlan-D spacesuits used for the EVA experienced a cooling water pump failure. The crew member was able to overcome the failure by operating the primary and backup circulating fans simultaneously and occasionally resting. A physician later reported that the hands of both EVA crew members were injured.
Source(s):
STS-41C | 4/11//1984 | EVA: 2
During the April 11th EVA, one of the crew members experienced a minor urine containment anomaly, but the Liquid Cooling and Ventilation Garment (LCVG) absorbed most of the leakage. The crew member also noticed some helmet fogging. The fogging was due to adjustments made to the flow of cooling water to the LCVG when the crew member became too cold.
Source(s):
STS-41C | 4/8//1984 | EVA: 1
During the April 8th EVA, hardware configuration differences prevented the EVA crew member from capturing a satellite as planned. A grommet, which was on the satellite but did not appear in the blueprints, prevented the Trunnion Pin Attachment Device jaws from closing onto one of the satellite’s berthing docking pins. The failed attempts caused the satellite to lose sun-lock and begin to tumble. The EVA was forced to end early when readings indicated that the Manned Maneuvering Unit nitrogen propellant supply was low.
Source(s):
STS-41B | 2/7/1984 | EVA: 1
During the February 7th EVA, one of the quick-release pins (pip-pin) pulled free from the bracket used to secure the EVA slidewire, which allowed crew members to freely move in the payload bay while remaining safely tethered to the shuttle. The most probable cause of the pip-pin pulling free was an inadvertent pull on the push-pull type t-handle, possibly from an EVA tether, which would unlock the detent balls holding the pin in place and release it from the bracket.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Salyut 7 PE-1 | 7/30/1982 | EVA: 1
During the July 30th EVA, the hand of a crew member testing an experimental wrench went numb. When using the tool, the crew member’s wrist was pressed against the suit wrist ring which caused the numbness.
Source(s):
STS-96/2A.1 | 5/27-6/6/1999
During the flight of STS-96, the Simplified Aid for EVA Rescue (SAFER) NASA Standard Initiator (NSI) inadvertently fired sometime between May 27th and June 6th. The event likely happened either as crew members were egressing the airlock or after the EVA when removing the SAFER. The firing of the NSI resulted in the pyrotechnic isolation valve opening, causing a loss of gaseous nitrogen. Post-EVA checkouts were not part of the planned post-EVA operations, so the anomaly was not noticed until ground inspections occurred following the flight. The anomaly would have had minimal, if any, impact on the crew member’s ability to perform self-rescue during an EVA, because of the low observed leakage rate through the SAFER thrusters. If a worst-case leak rate happened on all thrusters before an EVA, a very low amount of gaseous nitrogen might have been left at the end of the EVA, which could have compromised the ability to perform self-rescue if required.
Source(s):
STS-86 | 10/1/1197 | EVA: 1
A SAFER pyro failed to fire during the SAFER developmental test objective (DTO). The pyro valve failure was not discovered until a post-flight inspection of the SAFER hardware, since the DTO was performed with the crew member in a foot restraint. The failure triggered an investigation into the pyro and the redesign of the pyro system. Had this failure occurred during a self-rescue, the crew member would have been lost due to the latent design issue.
Source(s):
STS-80 | 11/29/1996 | EVA: 1
The November 29th EVA was terminated before the EVA crew members could leave the airlock. They were unable to unlatch the outer airlock hatch. Post-flight inspection determined that the failure was caused by a loose screw lodged within the hatch actuator mechanism gears.
Source(s):
STS-63 | 2/9/1995 | EVA: 2
The February 9th EVA was terminated early after the crew reported experiencing “level 3”cold (“unacceptably cold”) on a 1 to 8 scale created before launch.
After the EVA, when one crew member removed their helmet, the crew member noted an odor and suffered burning eyes. An air sample was taken, and the crew member washed their eyes with water. Post-flight analysis revealed no contaminants, and the most likely cause was contact with the anti-fogging soap solution.
Source(s):
STS-61 | 12/5/1993 | EVA: 2
During the December 5th EVA, one of the EVA crew members experienced difficulty receiving radio communications from Space Shuttle Endeavour and the ground. The other EVA crew member served as a relay, instead of the first crew member switching to a backup that would prevent downlinking of biomedical data to the ground.
Source(s):
Mir PE-14 | 10/22/1993 | EVA: 4
The October 22nd EVA had to be terminated early when a problem occurred with the oxygen flow system of an EVA crew member’s Russian Orlan-DMA spacesuit. The suit had been worn 13 times and had exceeded its recommended operational lifespan. The suit was declared non-operational for further EVAs and was jettisoned out the airlock on a subsequent EVA.
Source(s):
Mir, PE-14 | 9/28/1993 | EVA: 3
The September 28th EVA had to be terminated early due to a failure of the cooling system of one of the Russian Orlan-DMA spacesuits. Ground control considered having the other EVA crew member complete the EVA alone, but decided against the idea.
Source(s):
STS-57 | 6/25/1993 | EVA: 1
During the June 25th EVA, while the EVA crew members were away from the payload bay and oriented toward space, they became cold enough to start shivering and experienced numbness and pain in their hands.
Also during the EVA, an untethered piece of Inertial Upper Stage tilt table equipment was almost lost, but was retrieved by one of the crew members.
Source(s):
Mir, PE-13 | 4/19/1993 | EVA: 1
During the April 19th EVA, telemetry from one of the Russian Orlan spacesuits indicated that the suit’s ventilation system was not functioning properly. Despite the anomaly the EVA was allowed to continue as planned, and all tasks were completed.
Source(s):
Mir, PE-10 | 12/20/1992 | EVA: 1
At the beginning of the February 20th EVA, the heat exchanger of one Russian Orlan spacesuit clogged, forcing the crew member to remain near the Kvant 2 Special Airlock Compartment so that an umbilical from the Kvant 2 module heat exchanger could be attached to the suit. Because the umbilical was needed, the EVA crew member’s range of movement was limited, and the other EVA crew member had to conduct portions of the EVA alone.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Mir, PE-9 | 7/27/1991 | EVA: 6
During the July 27th EVA the heat exchanger of one of the Russian Orlan spacesuits ran out of water. The lack of cooling water and the EVA workload resulted in that crew member’s helmet visor fogging from the increase in moisture in the suit. The affected crew member was guided back to the airlock by the other EVA crew member.
After the EVA, the crew members reported bruises on their hands, elbows, and shoulders.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
STS-37 | 4/8/1991 | EVA: 2
After the April 8th EVA, the second consecutive EVA on STS-37, the exhausted EVA crew members recommended against performing future EVAs on consecutive days because of time constraints and fatigue.
Source(s):
STS-37 | 4/7/1991 | EVA: 1
During post-flight inspection it was discovered that the palm bar in the right hand glove worn by one crew member had shifted and punctured the restraint and glove bladder. It was determined that the palm bar was in an incorrect position due to insufficient restraints in the palm restraint tunnel allowing it to penetrate through a non-reinforced area of the palm restraint strap tunnel. To prevent recurrences of this anomaly, the palm bar strap was modified with stitching to prevent the bar from moving within the tunnel.
Source(s):
Mir, PE-8 | 1/26/1991 | EVA: 3
During the January 26th EVA, one of the crew members inadvertently kicked the Kurs docking antenna, knocking off one of the parabolic dishes. The issue was not discovered until a subsequent EVA on April 25th was conducted to determine why the visiting Progress M-7 failed to get a lock on the Kurs antenna.
Source(s):
Mir, PE-6 | 7/17/1990 | EVA: 1
At the beginning of the July 17th EVA, the EVA crew members inadvertently turned the airlock hatch handwheel farther than they were supposed to, violating the Kvant-2 airlock egress procedure and damaging the airlock. The normal procedure was to turn the handwheel until a 1-2 mm (0.04-0.08 in) gap opened around the lip of the hatch opening, allowing air to escape before the retaining hooks were released. Because the crew members turned the handwheel too far, the hooks released prematurely while there was still pressure in the airlock, causing the airlock to spring back against its hinges with 400 kg (880 lbs) of force. At the end of the EVA the crew members entered the airlock (after exceeding the 6-hr Russian Orlan-DMA suit safety limit) and discovered that they could not close the airlock
Source(s):
STS-128/17A | 9/5/2009 | EVA 3
During the September 5th EVA, the Extravehicular Mobility Unit (EMU or spacesuit) camera and light detached from the EMU helmet. The camera and light were prevented from floating away by the electrical cable, mitigating a risk for collision with ISS.
Source(s):
JKO EVA history STS-128 EVA 3
STS-127/2JA | 7/22/2009 | EVA 3
During the July 22nd EVA, the crew members’ high metabolic rates exceeded the design limitations of the Extravehicular Mobility Unit (EMU or spacesuit) carbon dioxide scrubbing system, resulting in one of the EVA crew members experiencing elevated carbon dioxide levels. The EVA was terminated after only two of four new ISS batteries had been installed, leaving the ISS in a configuration with limited operational capability.
Source(s):
STS-125/HST | 5/17/2009 | EVA 4
Near the end of the May 17th EVA, a tear in the palm bar of one EVA crew member’s Extravehicular Mobility Unit (EMU or spacesuit) glove triggered an early termination. Because the termination happened during the cleanup phase of the EVA, there were no additional operational impacts.
Source(s):
JKO EVA history STS-125 EVA 4
RS EVA 21A | 3/10/2009
During the March 10th EVA, the EVA crew members were working close to the port side Service Module solar array. While translating past the array to the EVA worksite, NASA ground controllers noticed the array was still rotating. Per flight rules the solar arrays should have been in the parked position for the EVA to prevent inadvertent contact with the crew member. Russian flight control was notified, and the array was placed into the parked position prior to the EVA crew members moving past it again.
Source(s):
RS EVA 21A Execute Shift Report
STS-126/ULF2 | 11/24/2008 | EVA: 4
The November 24th EVA was terminated as the crew members were entering the airlock at the end of the EVA after one of the EVA crew members experienced higher than acceptable levels of carbon dioxide.
Source(s):
STS-126/ULF2 | 11/20/2008 | EVA: 2
The November 20th EVA was terminated early after one of the EVA crew members experienced higher than acceptable levels of carbon dioxide. Once the crew member had returned to the airlock, the carbon dioxide returned to acceptable levels.
Source(s):
https://wiki.jsc.nasa.gov/eva/index.php/STS-126/ULF-2_EVA_2
RS EVA 20A | 7/10/2008
During the July 10th EVA, a planned jettison of the Soyuz thruster cover resulted in the cover colliding with one of the U.S. radiators. Because of the impact to the radiator, a survey was requested to check for damage. During the survey, damage was noted to the S1 radiator, but it was not determined if the damage came from the impact from the thruster cover.
Source(s):
STS-120/10A | 10/30/2007 | EVA: 3
After the October 30th EVA, one Extravehicular Mobility Unit (EMU or spacesuit) was deemed unusable due to a degraded sublimator. The sublimator water outlet temperature was higher than expected and had been trending upward on two prior EVAs. After the EVA the EMU was declared unusable for additional planned EVAs. Prior to the failure, the sublimator was used for STS-115 and STS-117 and had also shown high exit temperatures during those EVAs.
Source(s):
STS-118/13A.1 | 8/15/2007 | EVA: 3
The August 15th EVA was terminated early per flight rules after a small hole was discovered in the Vectran layer of on crew member’s glove during a routine glove check between tasks. The cause of the glove damage was unable to be determined after an extensive review of the video from the EVA.
Source(s):
https://wiki.jsc.nasa.gov/eva/index.php/STS-118/13A.1_EVA_3
STS-116/12A.1 | 12/26/2006 | EVA: 1
During the December 12th EVA, one crew member’s Simplified Aid for EVA Rescue (SAFER) Hand Controller Module (HCM) inadvertently deployed during airlock egress. The other EVA crew member re-stowed the HCM on the second attempt. The inadvertent deployment of the HCM caused the SAFER NASA Standard Initiator, or pyro, to accidently fire, which pressurized the SAFER thrusters and could have led to an inadvertent firing of the thrusters inside the airlock. The on-board spare SAFER was used for the subsequent EVAs. Flight rules were established after this flight for the crew to check the status of the SAFER after EVA if the HCM was inadvertently deployed.
Source(s):
STS-121/ULF1.1 | 7/10/2006 | EVA: 2
During the July 10th EVA, left side upper latch of one crew member’s Simplified Aid for EVA Rescue (SAFER) came unlatched, resulting in it disengaging from the Extravehicular Mobility Unit (EMU or spacesuit). The EVA was suspended until the SAFER could be secured by the other crew member to prevent losing the SAFER unit. The unlatching was attributed to accidental contact with the latch in a tight working space, and Kapton tape was used on the subsequent EVA to make sure the SAFER latches remained closed.
Source(s):
RS EVA 9A | 6/24/2004
The June 24th EVA was cut short due to a primary oxygen tank pressure anomaly with one of the Russian Orlan-M spacesuits. The cause of the anomaly was traced to an open oxygen flow switch on the suit. The switch was not fully placed into the normal flow position, which caused an unexpected flow of oxygen into the suit and a depletion of the Orlan suit’s oxygen supply at the beginning of the EVA. Crew EVA procedures were updated to ensure the handle is in the proper position to prevent a future recurrence of this issue.
Source(s):
ISS Exp-9 | 5/19/2004 | U.S. EVA Ops
During pre-EVA checkout operations on May 19th, an anomaly occurred with the Extravehicular Mobility Unit (EMU or spacesuit) cooling loop. The cause of the failure was contamination in the cooling water, which caused the EMU water pump rotor to jam. The failure resulted in the loss of U.S. EVA capability aboard the ISS until November 2005. Analysis performed on hardware returned to the ground helped to develop a process to maintain the on-orbit system. The process involves using a filtration system before and after EVA operations to maintain the quality of the loop coolant and to clean the EMU coolant water before storage.
Source(s):
STS-100/6A | 4/24/2001 | EVA: 3
During the April 24nd EVA, one of the EVA crew members experienced two instances of eye irritation similar to what was experienced on the prior EVA. The crew member observed that water escaped from the in-suit drink bag and was floating near the visor. The eye irritation was likely caused by water from the in-suit drink bag leaking and contacting the helmet visor and then the crew member’s eyes. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
STS-100/6A | 4/22/2001 | EVA: 2
During the April 22nd EVA, one of the EVA crew members experienced an irritation in one eye and was told to perform a helmet purge to clear any particulates. The purge did not help the irritation, which eventually spread to both eyes. Approximately 30 minutes later the irritation began to subside due to natural eye tearing. The irritation was believed to have been caused by water from the in-suit drink bag leaking and contacting the helmet visor and then the crew member’s eyes. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
STS-97/4A | 12/3/2000 | EVA: 1
During the December 3rd EVA, one of the EVA crew members coughed shortly after taking a sip of water. This caused liquid to bounce off the helmet visor, landing in the crew member’s right eye and causing a burning sensation. The crew member was instructed to ingress the airlock and purge the helmet to remedy the irritation. The cause of the eye irritation is believed to be the anti-fog agent used inside the helmet. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
U.S. EVA 46 | 10/20/2017
During U.S. EVA 46 the SAFER was inadvertently activated. A SAFER checkout was performed after the EVA which confirmed that the pyro valve had fired during the EVA and resulted in the depletion of the nitrogen gas tanks. No rescue capability exists after depletion. In this case a crew member who inadvertently detached would have had no self-rescue capability.
Source(s):
U.S. EVA 42 | 5/12/2017
ISS Increment 51: During U.S. EVA 42 the ISS EMU Service and Cooling Umbilical (SCU) leaked during the EVA pre-breathe, causing a "softball sized" water bubble. Flight rules allow the crew member to go EVA with only one SCU available, but that means one crew member has to depressurize and repressurize without cooling and EVA duration may have to be shortened due to more time on battery power during depress. The crew reported almost unbearable temperatures during depress. In the event of an early EVA termination when no cold-soak time is available, crew members may be exposed to extreme temperatures during repress as well when only one SCU is available. The SCU was redesigned with strain relief to avoid future leaks and reduce the likelihood of one level of cooling capability being unavailable at the start of an EVA.
Source(s):
US EVA 42 S/G Debrief Transcript – FINAL
(Restricted Access – contains PII (personally identifiable information) protected under the Privacy Act of 1974, as amended)
U.S. EVA 41 | 3/30/2017
During U.S. EVA 41, helmet lights detached from the helmet, but were held captive by the electrical cable. This is a recurrence of an event in September 2009. This failure could have impaired the crew member’s ability to perform nominal and emergency tasks, such as rapid emergency ingress during insolation.
Source(s):
U.S. EVA 38 | 1/6/2017
During U.S. EVA 38, EV2’s right glove was used in a hammer-like motion to free a work light. Ground teams could not determine whether the glove had been internally damaged, so the gloves were restricted from further flight use (downgraded to class C) after the EVA.
Source(s):
U.S. EVA 35 | 1/15/2016
The January 15th EVA was terminated early after water was observed in one EVA crew member’s helmet. The Extravehicular Mobility Unit (EMU or spacesuit) used for the EVA was the same one which had experienced previous water-in-helmet anomalies on EVAs 22 and 23. After this incident the EMU was declared unusable for future EVAs. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
NASA making progress on EVA-35 water leak incident _ NASASpaceFlight.com
U.S. EVA 32 | 10/28/2015
During depressurization for U.S. EVA 32, the feedwater switch of EMU 3010 was inadvertently switched on prior to the airlock being at vacuum. This allowed water to flow into the sublimator prior to the airlock environment reaching the triple point of water, which could have caused significant damage to the sublimator, resulting in loss of cooling capability and possible internal and external water leaks posing a hazard to the crew member. Subsequent failure or inability to quickly return to the airlock could lead to loss of crew. The EVA proceeded, but flight rules were subsequently updated to document that an inadvertent feedwater switch activation prior to 0.5 psia requires EVA termination.
Source(s):
U.S. EVA 25 | 12/24/2013
During the December 24th EVA, the EVA crew members experienced difficulty disconnecting ammonia fluid lines and reported seeing ammonia flakes escaping a valve while disconnecting the lines. The quick-disconnect button on the valve could not be pushed, requiring the crew to use a tool called the Bail Control Tool, that had been developed after previous issues with quick disconnects. The crew successfully demated the quick disconnect, replaced the failed Pump Module, and completed the necessary suit decontamination procedures before entering the ISS. The decontamination procedures consist of the crew members staying in the sun for a period of time prior to ingressing the airlock, also known as a “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
ISS Expedition 38 US EVA 25 Updates - Spaceflight101
U.S. EVA 24 | 12/21/2013
After returning to the airlock at the end of the December 21st EVA, one crew member accidentally actuated the Extravehicular Mobility Unit’s (EMU’s or spacesuit’s) Feedwater Switch for 2-3 seconds. Water flooded the sublimator, which can cause irreparable damage to the EMU, and the suit was declared unusable for EVA until proper drying procedures were performed.
Source(s):
U.S. EVA 23 | 7/16/2013
On July 16th about 44 minutes into the EVA, one crew member reported water in the helmet of the Extravehicular Mobility Unit (EMU or spacesuit). The EVA ground team and the crew member were unable to determine the source of the water. While the EVA continued, the amount of water in the helmet increased and eventually migrated from the back of the crew member’s head to his face. Approximately 1 to 1.5 liters of water had entered the EMU’s ventilation loop and collected in the EMU helmet. At this point the EVA was terminated and the crew member was able to find the way back to the airlock, despite the water obscuring his vision. All EVA crew members safely entered the airlock and re-pressurized.
Source(s):
Suit Water Intrusion Mishap Investigation Report
U.S. EVA 22 | 7/9/2013
During the July 9th EVA, one of the crew members noticed water in the Extravehicular Mobility Unit (EMU or spacesuit) helmet. At the time the water was incorrectly attributed to a leaking drink bag. This event was a precursor event to the anomaly on ISS EVA 23. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
Suit Water Intrusion Mishap Investigation Report
U.S. EVA 18 | 8/30/2012
During the August 30th EVA, telemetry sent back to the ground controllers indicated that one of the Extravehicular Mobility Units (EMUs or spacesuits) was experiencing an unexpected cooling water temperature increase. Following the EVA the EMU suit was declared unusable for future EVAs and returned to Earth for investigation. The investigation determined that the cause of the temperature increase was a degradation in sublimator performance due to contamination from an unknown source.
Source(s):
STS-134/ULF6 | 5/25/2011 | EVA: 3
During the May 25th EVA, one of the EVA crew members experienced eye irritation. The most probable cause was the helmet anti-fogging agent. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
STS-134/ULF6 | 5/20/2011 | EVA: 1
Near the end of the May 20th EVA, one of the EVA crew members received the “Carbon Dioxide Sensor Bad” message. Because of the failure of the carbon dioxide sensor, the EVA was terminated early. The most likely cause of the failure was high humidity in the vent loop due to high oxygen use rates, along with the EVA taking place in a cool thermal environment. The sensor was dried out prior to the next EVA and functionality was restored.
Source(s):
Realtime coverage of STS-134 EVA No. 3
U.S. EVA 16 | 8/11/2010
During the August 11th EVA, one of the EVA crew members was exposed to ammonia from a leaking connector (quick disconnect) and experienced difficulty actuating the quick disconnect. The quick disconnect was eventually de-mated successfully, allowing for the subsequent removal and replacement of the failed coolant pump. Because the amount of leaking ammonia was small, the time required to finish the EVA allowed the ammonia to sublimate off the suit and decontamination procedures were not required at the end of the EVA.
Source(s):
CBS News Space Place - Space News ISS-24
U.S. EVA 15 | 8/7/2010
During the August 7th EVA, one of the EVA crew members was exposed to ammonia from a leaking connector (quick disconnect) and experienced difficulty actuating the quick disconnect. The EVA crew completed suit decontamination procedures prior to ingressing the airlock. These procedures consist of the crew members staying in the sun for a period of time, also known as “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
STS-130/20A | 2/17/2010 | EVA 3
During the February 17th EVA, large water droplets were observed in one EVA crew member’s helmet. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
STS-130/20A | 2/14/2010 | EVA 2
During the February 14th EVA, one crew member was exposed to ammonia from a leaking connector (quick disconnect). The EVA crew completed suit decontamination procedures prior to ingressing the airlock. These procedures consist of the crew members staying in the sun for a period of time, also known as a “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
STS-130/20A | 2/1/2010 | EVA 1
During the February 11th EVA, one of the EVA crew members noticed water in the Extravehicular Mobility Unit (EMU or spacesuit) helmet and in the EMU boots. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
JKO EVA history STS-130 EVA 1
STS-88 | 12/7/1998 | EVA: 1
During the December 7th EVA an EV crew member pushed off from the ISS in an attempt to retrieve a lost object.
Sources:
Space Shuttle STS-88 EVA, rare B roll NASA video footage (1:31 minute mark)
Wikipedia video (2:44 minute mark)
STS-51D | 4/16/1985
During an unplanned EVA a crew member became inadvertently detached from the orbiter and tumbled out of the payload bay, bouncing off of the wing of the orbiter. The crew member was able to pull themselves back in to the payload bay using their safety tether.
Source(s):
https://wiki.jsc.nasa.gov/iss/index.php/Simplified_Aid_For_EVA_Rescue
U.S. EVA 53 | 3/29/2019
During U.S. EVA 53, while EV1 was relocating an APFR at 14:28 GMT, the crew member reported the Ingress Aid came off the APFR in their hand. The crew attached a retractable tether and did an inspection, reporting the collar was unlocked. The ingress aide was reinstalled and locked, with a good pull test.
During debrief, EV1 stated they may have inadvertently depressed and rotated the collar with the EMU boot while ingressing the APFR.
Source(s):
U.S. EVA 62 | 1/15/2020
During the January 15th EVA, crew members reported that EV2’s EMU Radio Frequency Camera Assembly (ERCA) and helmet lights had come loose from EV2’s helmet. Ground teams could tell from the video that the ERCA and light assembly were completely separated from the helmet and only attached via the power cable. The EV crew members attached the assembly to the side of a crew-lock bag to prevent the loss of the equipment and continued with the EVA.
Source(s):
U.S. EVA 64 | 1/25/2020
While depressing the airlock for the January 25th EVA, the Flight Control Team noticed a slower-than-expected depress rate. After the crew confirmed that the Depress Pump Manual Isolation Valve was fully open, EV2 inspected the hatch and reported that a strap was stuck in the IV hatch of the airlock. An IV crew member checked the hatch from the IV side and confirmed the hatch indicator was fully latched, but airflow could be felt around the hatch edge. The depress was halted, and the IV hatch equalization valve was opened to re-pressurize the airlock. After equalization, the hatch was opened, and the IV crew inspected the hatch seal for any signs of damage. After no damage was found, the hatch was re-closed and the depress resumed.
Source(s):
U.S. EVA 62 | 1/15/2020
Following completion of the January 15th EVA, it was learned that one of the EV crew members experienced eye irritation during EVA.
Source(s):
U.S. EVA 63 | 1/20/2020
While performing the January 20th EVA, a crew member experienced eye irritation. The crew member reported adjusting the temperature control colder seemed to help.
Source(s):
STS-98/5A | 2/10/2001 | EVA: 1
During the February 10th EVA, one of the EVA crew members was sprayed with ammonia from a leaking connector (quick disconnect). The EVA crew completed suit decontamination procedures prior to ingressing the airlock. These procedures consist of the crew members staying in the sun for a period of time, also known as a “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
STS-98 | 2/12/2001 | EVA: 2
Source(s):
RS EVA 10 | 8/3/2004
During the August 3rd EVA, the ISS went into free drift while both of the crew members were conducting the EVA and no crew members remained inside. The three active Control Moment Gyroscopes (CMGs) that control the orientation of the ISS neared their saturation level. As a result the station entered free drift, resulting in a temporary loss of communications with mission control (S-band). Once the crew members had moved away from the area around the service module, the inhibited thrusters were re-enabled and fired to desaturate the CMGs.
Source(s):
Expedition 9 Crew Prepares for Final Spacewalk
RS EVA 13 | 3/28/2005
Source(s):
What does EVA stand for?
EVA is a commonly used acronym for Extravehicular Activity, which describes any activity for which a crew member must go outside the protected environment of the spacecraft. It is sometimes commonly referred to as "Spacewalking."
For more information, please visit:
Significant Incidents & Close Calls in Human Spaceflight: EVA Operations
INADVERTANT RELEASES
EVA HOURS
SUIT GUIDE
ACRONYMS
THE TEAM
FSO TOOLS
ABOUT
An “inadvertent release” is when an item (tool, fastener, bag, etc.), which should be restrained, becomes unintentionally freed and floats away.
MISSION ID
Gemini 4
Gemini 10
Salyut-7
STS-41B
STS-41C
STS-41G
STS-51A
STS-51L
Mir
STS-88/2A
STS-88/2A
STS-96/2A.1
STS-103/HST
STS-101/2A.2a
STS-92/3A
STS-100/6A
EVA
1
1
1
2
2
1
2
1
PE-13
1
2
1
3
1
3
2
# LOST
1
1
1
1
1
1
2
1
1
4
3
1
1
1
1
1
YEAR
1965
1966
1983
1984
1984
1984
1984
1985
1993
1998
1998
1999
1999
2000
2000
2001
MISSION ID
STS-104/7A
STS-102/5A.1
ISS-4
ISS-11
ISS-12
ISS-13
STS-121/ULF1.1
STS-115/12A
STS-115/12A
STS-116/12A.1
STS-116/12A.1
ISS-14
ISS-15
STS-120/10A
ISS-16
ISS-16
EVA
3
1
RS 6
U.S. 13
U.S. 4
RS 16
3
1
2
1
3
RS 17A
RS 18
4
U.S. 11
U.S. 13
# LOST
1
2
1
1
1
1
1
1
1
1
1
3
1
2
1
4
YEAR
2001
2002
2002
2005
2005
2006
2006
2006
2006
2006
2006
2007
2007
2007
2007
2007
MISSION ID
ISS-16
STS-124/1J
STS-126/ULF2
ISS-24
ISS-25
ISS-26
STS-133/ULF5
STS-134/ULF6
ISS-28
ISS-35
ISS-39
ISS-50
ISS-53
ISS-56
ISS-59
EVA
U.S. 14
2
1
RS 25
RS 26
RS 27
1
2
RS 29
RS 32
US 26
U.S. 41
U.S. 44
U.S. 51
U.S. 53
# LOST
1
1
1
4
1
1
1
4
1
1
2
1
1
1
1
YEAR
2008
2008
2008
2010
2010
2011
2011
2011
2011
2013
2014
2017
2017
2018
2019
Cumulative Hours as of 7/27/2016
U.S. - 1639
Russian - 711
China - 1
1960s
1970s
1980s
1990s
2000s
2010s
2020s
900
Total Hours by decade.
U.S., Russian, and Chinese
557
470
121
146
25
1960s
1970s
1980s
1990s
2000s
2010s
44
2020s
G4C | 6/3/1965-11/15/1966 | Gemini (4-6, 8-12)
The G4C suit was used by Ed White during the Gemini IV mission to perform the first U.S. spacewalk. The suit used a “combination of a pressure bladder and a link-net restraint” * to improve mobility over the previous Mercury suit when pressurized. The suit also provided thermal insulation and micrometeoroid protection. The suit relied on a 25-foot tether to supply oxygen from the spacecraft, communication, a medical telemetry link, and a mechanical attachment to the spacecraft. A sunvisor was attached to the helmet. The life support system was an open-loop design (breathing gas flowing into the suit and venting overboard). In addition to providing breathing oxygen for the crew member, the open-loop flow provided cooling and removed carbon dioxide and moisture. Cooling was controlled with a chest-mounted Ventilation Control Module. The suit operated at 3.7 psi.
Source(s):
Space Suit Evolution From Custom Tailored To Off-The-Rack
Joseph J. Kosmo, Space Suit Extravehicular Hazards Protection Development
JSC/EC5 U.S. Spacesuit Knowledge Capture (KC) Series Synopsis
A7L, all variants | 3/6/1969 – 2/3/1974 | Apollo, Skylab
The A7L was a custom-tailored spacesuit used for all the Apollo and Skylab spacewalks. It is sometimes called the “Moonsuit,” since it was used by everyone who walked on the moon to date. It was a “soft suit” since it did not rely on a rigid shell to retain its shape. Instead, various structural fabrics, straps, and cables maintained the shape while pressurized. Special joints at the ankles, knees, hips, shoulders, elbows, and wrists aided crew mobility. Later Apollo missions used the A7LB suit, which included neck and waist joints to allow the crew to operate the lunar rover. The suit was a closed-loop system that operated at a pressure of 3.7 psi and used a liquid cooling system for temperature control. When used on the moon and for other non-lunar Apollo EVAs, the suit included a backpack that contained the oxygen supply, carbon dioxide removal, batteries, cooling water, and radios. The Skylab-based EVAs did away with the backpack and used an umbilical.
Source(s):
Joseph J. Kosmo, Space Suit Extravehicular Hazards Protection Development
EMU, all variants | 4/7/1983 - present | STS, ISS
The EMU was used for the Space Shuttle Program and is currently in use on the International Space Station. The semi-rigid design includes a hard upper torso with the helmet and primary life support system (PLSS) backpack attached to it. The flexible lower torso, arms, and legs use straps, cables, and pressure bearings to control ballooning and increase flexibility while pressurized. Unlike the early NASA spacesuits that were custom tailored for each crew member, the EMU uses interchangeable components and resizing mechanisms to allow use by various crew members. The suit is a closed-loop system operating at a pressure of 4.3 psi and uses a water sublimation system for cooling. The PLSS is designed to support the crew for up to eight hours. A secondary oxygen pack provides additional oxygen in case of an emergency.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Joseph J. Kosmo, Space Suit Extravehicular Hazards Protection Development
Space Suit Evolution From Custom Tailored To Off-The-Rack
Space Suits & Related Products
Berkut (Golden Eagle) | 3/18/1965 | Voskhod 2
The Berkut was used by Alexi Leonov to perform the world’s first spacewalk. Its design was based on the Vostok Sokol-1 suit, which had been used as a launch and entry suit to protect the crew members in case the capsule developed a leak. Modifications for use during spacewalks included the addition of a backpack life support system, a thermal protection layer on the outside, a sun visor on the helmet, and a safety tether to connect the suit to the capsule. The steel safety tether also provided backup oxygen, a mechanical load-relieving device, biomedical and suit telemetry, and a communication link with the capsule. The life support system was an open-loop design (breathing gas flowing into the suit and venting overboard) consisting of a backpack supplying 45 minutes of oxygen and a seven-meter umbilical that attached to backup supply of oxygen. In addition to providing breathing oxygen for the crew member, the open-loop flow provided cooling and removed carbon dioxide and moisture. The suit normally operated at a pressure of 5.88 psi, but could be reduced to 3.67 psi for contingency operations.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Yastreb (Hawk) | 1/16/1969 | Soyuz 4&5
The Yastreb suit was developed based on the lessons learned from the first Russian EVA and was used for the second Russian EVA – a transfer by spacewalk of two crew members from Soyuz 4 to Soyuz 5. A system of built-in restraints was used to control the ballooning that was experienced with the Berkut suit. Another design change was to remove the life support pack from the back of the suit and instead affix it to either the chest or leg to make it easier for the crew to get in and out of the spacecraft. The suit relied on a steel safety tether, which also provided backup oxygen, a mechanical load-relieving device, biomedical and suit telemetry, and a communication link with the capsule. The life support system was an open-loop design (breathing gas flowing into the suit and venting overboard) consisting of a pack supplying 45 minutes of oxygen and a seven-meter umbilical that attached to a backup supply of oxygen. In addition to providing breathing oxygen for the crew member, the open-loop flow provided cooling and removed carbon dioxide and moisture. The suit normally operated at a pressure of 5.88 psi, but could be reduced to 3.67 psi for contingency operations.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Orlan (Sea Eagle), all variants | 12/20/1977 – present | Salyut, Mir, ISS
The Orlan spacesuit replaced the Yastreb as the Soviet/Russian EVA spacesuit. The suit is a semi-rigid design (i.e., a hard upper torso with attached helmet and backpack). The suit simplifies donning by having the backpack double as a hatch. The flexible lower torso, arms, and legs use straps, cables, and pressure bearings to control ballooning and increase flexibility while pressurized. Where feasible, redundant pressure bladders, seals, and systems are used. The suit also differs from the Berkut and Yastreb suits in that it uses a closed-loop ventilation system and a liquid cooling system for thermal control. The initial design of the Orlan used a tether to supply oxygen, electrical power, and voice and data communications. Later models incorporated the oxygen supply, power (batteries), and radios (voice and data telemetry) into the suit to eliminate the need for the umbilical. In place of the umbilical, the crew uses safety tethers to connect the suit to the spacecraft or space station. The Orlan operates at a pressure of 5.8 psi.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
G4C
A7L, all variants
EMU, all variants
Berkut
Yastreb
Orlan, all variants
EXECUTIVE SPONSOR
TEAM LEAD
RESEARCH & INFOGRAPHIC DESIGN
GRAPHIC DESIGNER
Gail Skowron, Ph.D.
Scott Johnson
Patrick Huckaby
Dennis Pate
Joanna Opaskar
Faisal Ali
OTHER CONTRIBUTORS
Andy Foster
Dennis Arnold
Everett Cole
Rufus Jackson
Gary Johnson
Tim Kassebaum
Barbara Kress
Jennifer Reister
David Salvador
Meredith Smith
Tieva De Koninck
Paula Smith
PAST CONTRIBUTORS
Bob Bobola David Bradt Stuart Monteleone Phillip Lewis Rusty Sheier Erin Stevenson Keith Tischler Ashley Tomi Amaris Vigil Ed Weissblatt Bill Wood Nigel Packham
The JSC SMA Flight Safety Office (FSO) created this graphic to highlight the risks of space exploration and to provide engineers with a summary of past experience. The chart depicts incidents during EVAs in orbit and on the lunar surface, which caused or could have caused injury, death, or the loss of the mission. Our goal is to encourage everyone to learn from the past to make present and future missions safer.
Incidents on the chart meet one or more of the following criteria:
ALSEP
APFR
CMG
DTO
EMU
ERCA
EVA
EV
FSO
HCM
HST
IRIS
ISS
IUS
IVA
JKO
JSC
LEM
LCVG
LRV
MMU
MWS
NASA
NSI
PE
PLSS
RCC
RS
S&MA
SAFER
SAIC
SCU
STS
ULF
U.S.
Apollo Lunar Surface Experiments Package
Articulating Portable Foot Restraint
Control Moment Gyroscope
Developmental Test Objective
Extravehicular Mobility Unit
EMU Radio Frequency Camera Assembly
Extravehicular Activity
EVA Crew Member
Flight Safety Office
Hand Control Module
Hubble Space Telescope
Incident Reporting Information System
International Space Station
Inertial Upper Stage
Intravehicular Activity
JSC Knowledge Online
Johnson Space Center
Lunar Excursion Module
Liquid Cooling and Ventilation Garment
Lunar Roving Vehicle
Manned Maneuvering Unit
Mini-Workstation
National Aeronautics and Space Administration
NASA Standard Initiator
Principal Expedition
Primary/Portable Life Support System
Reinforced Carbon-Carbon
Russian
Safety and Mission Assurance
Simplified Aid for EVA Rescue
Science Applications International Corporation
Service and Cooling Umbilical
Space Transportation System
Utilization Logistics Flight
United States
https://sma.nasa.gov/sma-disciplines/mishap-investigation
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1960s
25 hours = 24 U.S. + 1 Russia
18 EVAs = 16 U.S. + 2 Russia
1970s
121 hours = 116 U.S. + 5 Russia
32 EVAs = 29 U.S. + 3 Russia
1980s
145 hours = 69 U.S. + 77 Russia
33 EVAs = 13 U.S. + 20 Russia
1990s
557 hours = 231 U.S. + 326 Russia
107 EVAs = 35 U.S. + 71 Russia
2000s
900 hours = 755 U.S. + 144 Russia + 1 China
144 EVAs = 113 U.S. + 30 Russia
2010s
558 hours = 400 U.S. + 158 Russia
88 EVAs = 63 U.S. + 25 Russia
2020s
44 hours = 44 U.S.
7 EVAs = 7 U.S.
------Yastreb (Soyuz)
Orlan (Soyuz, Salyut, Mir, ISS)
------Berkut (Voskhod)
Feitian (Shenshou)------
CHINA
A7, A7LB (Apollo, LEM)
---G4C (Gemini)
EMU (Space Shuttle)
------A7LB (Skylab)
ISS EMU (International Space Station)
Voskhod 2
3/18/1965
Salyut 6 PE-1, EVA 1
12/20/1977
Salyut 6 PE-3, EVA 1
8/15/1979
Salyut 7 PE-1, EVA 1
7/30/1982
+
Salyut 7 PE-3, EVA 6
8/8/1984
+
Mir, PE-2, EVA 1
4/11/1987
Mir, PE-6, EVA 1
7/17/1990
Mir, PE-8, EVA 3
1/26/1991
Mir, PE-9, EVA 6
7/27/1991
+
Mir, PE-10, EVA 1
12/20/1992
Mir, PE-13, EVA 1
4/19/1993
Mir, PE-14, EVA 3
9/28/1993
Mir, PE-14, EVA 4
10/22/1993
RS EVA 9A
6/24/2004
RS EVA 10
8/3/2004
RS EVA 20A
7/10/2008
RS EVA 21A
3/10/2009
Voskhod 2 | 3/18/1965
During the March 18th 1965 EVA, the spacesuit the crew member was wearing while performing the EVA ballooned, causing an increase in the suit’s stiffness. After completing the EVA, the crew member entered the airlock head first and discovered that the suit would not bend enough to allow him to turn around and close the hatch. The crew member was forced to lower the pressure inside the suit, risking the potential onset of dysbarism (“the bends”). The struggle to enter and seal the airlock led to the crew member overheating, nearly to the point of heatstroke, due to the workload exceeding the cooling capacity of the early EVA suit.
Source(s):
http://www.astronautix.com/v/voskhod2.html
Salyut 6 PE-3 | 8/15/1979 | EVA: 1
After performing the EVA on August 15th, one of the crew members noticed a small puncture in the suit’s pressure bladder. The cause of the puncture was possibly a sharp wire on the KRT-10 antenna that the crew members removed from the Salyut 6 station.
Source(s):
Salyut 6 PE | 12/20/1977 | EVA: 1
On December 20th while performing an EVA from the Salyut 6 docking port, one crew member partially left the docking port without attaching the safety tether. While the crew member was untethered, the suit umbilical was still attached and prevented him from accidentally floating free of the station.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Mir, PE-2 | 4/11/1987 | EVA: 1
During the April 11th EVA, the Russian Orlan-DM spacesuit in use by one of the crew members experienced a minor pressure drop. The cause of the pressure drop was quickly determined to be an incorrect switch position, which was corrected, allowing the EVA to continue.
Source(s):
Salyut 7 PE-3 | 8/8/1984 | EVA: 6
During the August 8th EVA, one of the Russian Orlan-D spacesuits used for the EVA experienced a cooling water pump failure. The crew member was able to overcome the failure by operating the primary and backup circulating fans simultaneously and occasionally resting. A physician later reported that the hands of both EVA crew members were injured.
Source(s):
Salyut 7 PE-1 | 7/30/1982 | EVA: 1
During the July 30th EVA, the hand of a crew member testing an experimental wrench went numb. When using the tool, the crew member’s wrist was pressed against the suit wrist ring which caused the numbness.
Source(s):
Mir PE-14 | 10/22/1993 | EVA: 4
The October 22nd EVA had to be terminated early when a problem occurred with the oxygen flow system of an EVA crew member’s Russian Orlan-DMA spacesuit. The suit had been worn 13 times and had exceeded its recommended operational lifespan. The suit was declared non-operational for further EVAs and was jettisoned out the airlock on a subsequent EVA.
Source(s):
Mir, PE-14 | 9/28/1993 | EVA: 3
The September 28th EVA had to be terminated early due to a failure of the cooling system of one of the Russian Orlan-DMA spacesuits. Ground control considered having the other EVA crew member complete the EVA alone, but decided against the idea.
Source(s):
Mir, PE-13 | 4/19/1993 | EVA: 1
During the April 19th EVA, telemetry from one of the Russian Orlan spacesuits indicated that the suit’s ventilation system was not functioning properly. Despite the anomaly the EVA was allowed to continue as planned, and all tasks were completed.
Source(s):
Mir, PE-10 | 12/20/1992 | EVA: 1
At the beginning of the February 20th EVA, the heat exchanger of one Russian Orlan spacesuit clogged, forcing the crew member to remain near the Kvant 2 Special Airlock Compartment so that an umbilical from the Kvant 2 module heat exchanger could be attached to the suit. Because the umbilical was needed, the EVA crew member’s range of movement was limited, and the other EVA crew member had to conduct portions of the EVA alone.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Mir, PE-9 | 7/27/1991 | EVA: 6
During the July 27th EVA the heat exchanger of one of the Russian Orlan spacesuits ran out of water. The lack of cooling water and the EVA workload resulted in that crew member’s helmet visor fogging from the increase in moisture in the suit. The affected crew member was guided back to the airlock by the other EVA crew member.
After the EVA, the crew members reported bruises on their hands, elbows, and shoulders.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Mir, PE-8 | 1/26/1991 | EVA: 3
During the January 26th EVA, one of the crew members inadvertently kicked the Kurs docking antenna, knocking off one of the parabolic dishes. The issue was not discovered until a subsequent EVA on April 25th was conducted to determine why the visiting Progress M-7 failed to get a lock on the Kurs antenna.
Source(s):
Mir, PE-6 | 7/17/1990 | EVA: 1
At the beginning of the July 17th EVA, the EVA crew members inadvertently turned the airlock hatch handwheel farther than they were supposed to, violating the Kvant-2 airlock egress procedure and damaging the airlock. The normal procedure was to turn the handwheel until a 1-2 mm (0.04-0.08 in) gap opened around the lip of the hatch opening, allowing air to escape before the retaining hooks were released. Because the crew members turned the handwheel too far, the hooks released prematurely while there was still pressure in the airlock, causing the airlock to spring back against its hinges with 400 kg (880 lbs) of force. At the end of the EVA the crew members entered the airlock (after exceeding the 6-hr Russian Orlan-DMA suit safety limit) and discovered that they could not close the airlock
Source(s):
RS EVA 21A | 3/10/2009
During the March 10th EVA, the EVA crew members were working close to the port side Service Module solar array. While translating past the array to the EVA worksite, NASA ground controllers noticed the array was still rotating. Per flight rules the solar arrays should have been in the parked position for the EVA to prevent inadvertent contact with the crew member. Russian flight control was notified, and the array was placed into the parked position prior to the EVA crew members moving past it again.
Source(s):
RS EVA 21A Execute Shift Report
RS EVA 20A | 7/10/2008
During the July 10th EVA, a planned jettison of the Soyuz thruster cover resulted in the cover colliding with one of the U.S. radiators. Because of the impact to the radiator, a survey was requested to check for damage. During the survey, damage was noted to the S1 radiator, but it was not determined if the damage came from the impact from the thruster cover.
Source(s):
RS EVA 10 | 8/3/2004
During the August 3rd EVA, the ISS went into free drift while both of the crew members were conducting the EVA and no crew members remained inside. The three active Control Moment Gyroscopes (CMGs) that control the orientation of the ISS neared their saturation level. As a result the station entered free drift, resulting in a temporary loss of communications with mission control (S-band). Once the crew members had moved away from the area around the service module, the inhibited thrusters were re-enabled and fired to desaturate the CMGs.
Source(s):
Expedition 9 Crew Prepares for Final Spacewalk
RS EVA 9A | 6/24/2004
The June 24th EVA was cut short due to a primary oxygen tank pressure anomaly with one of the Russian Orlan-M spacesuits. The cause of the anomaly was traced to an open oxygen flow switch on the suit. The switch was not fully placed into the normal flow position, which caused an unexpected flow of oxygen into the suit and a depletion of the Orlan suit’s oxygen supply at the beginning of the EVA. Crew EVA procedures were updated to ensure the handle is in the proper position to prevent a future recurrence of this issue.
Source(s):
Gemini 4
6/3/1965
Gemini 9
6/5/1966
+
Gemini 10, EVA 1
7/19/1966
+
Gemini 10, EVA 2
7/20/1966
Gemini 11, EVA 1
9/13/1966
Apollo 11, EVA 1
7/20/1969
Apollo 12, EVA 2
11/2/1969
Apollo 15, EVA 2
7/31/1971
Apollo 15, EVA 3
8/1/1971
Apollo 16, EVA 1
4/21/1972
Apollo 16, EVA 2
4/22/1972
Apollo 16, EVA 3
4/23/1972
Apollo 17, EVA 1
12/11/1972
+
Skylab 2, EVA 2
6/7/1973
Skylab 3, EVA 3
9/22/1973
Skylab 4, EVA 1
11/22/1973
Skylab 4, EVA 2
12/25/1973
Skylab 4, EVA 3
12/29/1973
Skylab 4, EVA 4
2/3/1974
STS-41B, EVA 1
2/7/1984
STS-41C, EVA 1
4/8/1984
STS-41C, EVA 2
4/11/1984
STS-51I, EVA 2
9/1/1985
STS-37, EVA 1
4/7/1991
STS-37, EVA 2
4/8/1991
STS-57, EVA 1
6/25/1993
STS-61, EVA 2
12/5/1993
STS-63, EVA 2
2/9/1995
+
STS-80, EVA 1
11/29/1996
STS-86, EVA 1
10/1/1997
STS-96/2A.1
5/27-6/6/1999
STS-97/4A, EVA 1
12/3/2000
+
STS-98/5A, EVA 1
2/10/2001
STS-100/6A, EVA 2
4/22/2001
+
STS-100/6A, EVA 3
4/24/2001
+
Iss Exp-9 US EVA ops
5/19/2004
STS-121/ULF1.1, EVA 2
7/10/2006
STS-116/12A., EVA 1
12/12/2006
STS-118/13A.1, EVA 3
8/15/2007
STS-120/10A, EVA 3
10/30/2007
STS-126/ULF2, EVA 2
11/20/2009
STS-126/ULF2, EVA 4
11/24/2008
STS-125HST, EVA 4
5/17/2009
STS-127/21A, EVA 3
7/22/2009
STS-128/17A, EVA 3
9/5/2009
STS-130/20A, EVA 1
2/1/2010
STS-130/20A, EVA 2
2/14/2010
STS-130/20A, EVA 3
2/17/2010
U.S. EVA 15
8/7/2010
U.S. EVA 16
8/11/2010
STS-134/ULF6, EVA 1
5/20/2011
STS-134/ULF6, EVA 3
5/25/2011
+
U.S. EVA 18
8/30/2017
U.S. EVA 22
7/9/2013
U.S. EVA 23
7/16/2013
U.S. EVA 24
12/21/2013
U.S. EVA 25
12/24/2013
U.S. EVA 32
10/28/2015
U.S. EVA 35
1/15/2016
U.S. EVA 38
1/6/2017
U.S. EVA 41
3/30/2017
U.S. EVA 42
5/12/2017
U.S. EVA 46
10/20/2017
Apollo 12 | 11/2/1969 | EVA: 2
During the November 19th EVA, the crew members reported that the Extravehicular Mobility Unit’s (EMU or EVA suit) integrated thermal meteoroid garments were severely worn by the abrasive nature of the lunar dust. During the ascent to lunar orbit, the dust that was tracked into the Lunar Excursion Module became weightless, causing the crew members to experience difficulty breathing and requiring them to put on their helmets.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
James R. Gaier, The Effects of Lunar Dust on EVA Systems During the Apollo Missions
Apollo 11 | 7/20/1966 | EVA: 1
While egressing the Lunar Excursion Module (LEM), one of the crew members experienced difficulty crawling through the hatch due to tight clearances between the LEM hatch and the Portable Life Support System attached to the back of the suit.
Source(s):
Gemini 11 | 9/13/1966 | EVA: 1
During preparation for the September 13th EVA, the crew member that would be performing the spacewalk became overheated in the suit prior to egressing the capsule. Difficulty attaching the helmet visor contributed to the exertion and overheating. Because the life support oxygen cooling system heat exchanger could only operate in a vacuum, the crew member was not able to receive cooling from it. The EVA proceeded, but the crew member that remained in the capsule during the EVA brought the spacewalking crew member in early, noting that the crew member was sweating and not able to see well.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 10 | 7/20/1966 | EVA: 2
While moving over to the Agena docking target, the EVA crew member dislodged a sharp-edged electrical discharge ring that had the potential to damage the suit or its umbilical. After returning to the Gemini capsule, the EVA umbilical blocked one of the crew members from seeing the control panel, preventing the crew member from reporting the status of fuel to ground control. The difficulty that the crew members had with the umbilical also led to the radio accidentally being shut off for a brief time.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 10 | 7/19/1966 | EVA: 1
While executing the July 19th EVA, the crew member conducting the spacewalk experienced eye irritations causing the EVA to be terminated early. The cause of the irritation was traced to lithium hydroxide used for carbon dioxide absorption leaking into the helmet when both suit fans were operating simultaneously.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 9 | 6/5/1966
During the June 5th EVA, the crew member conducting the spacewalk experienced difficulty maneuvering around the outside of the capsule. While moving around during the EVA, the crew member’s suit became damaged, resulting in the crew member having thermal burns on his back from the sunlight striking the torn areas of the suit. The workload that the crew member experienced also exceeded the cooling capacity of the suit.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Gemini 4 | 6/3/1965
On June 3rd 1965 the crew of Gemini 4 experienced difficulty closing the capsule hatch after completion of the EVA. The crew was finally able to get the hatch closed when one crew member pulled on the other crew member while turning the hatch handle. While struggling to close the hatch, the crew member performing the spacewalk exerted himself beyond the cooling capacity of the suit, leading to slight fogging of the helmet visor.
Source(s):
http://www.astronautix.com/g/gemini4.html
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 2/3/1974 | EVA: 4
While performing the February 3rd EVA, one crew member’s suit cooling system developed a leak similar to the one experienced on EVA 2. The crew member switched to minimum cooling, minimizing the amount of cooling water leaking, and completed the tasks assigned for the EVA. A later investigation determined that the probable cause of the leaking was due to the connectors being exposed to the cold environment of space and a small side load being placed on the connector.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 12/29/1973 | EVA: 3
During the December 29th EVA, a cooling water leak caused ice to form on the front of one crew member’s suit. A later investigation determined that the probable cause of the leaking was due to the connectors being exposed to the cold environment of space and a small side load being placed on the connector.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 12/25/1973 | EVA: 2
During the December 25th EVA, a cooling water leak caused yellow ice to form on the front of one crew member’s belly-mounted pressure control unit. The color of the ice indicated that the leak was from one of the two water connectors (quick disconnects) of the composite connector at the interface of the life support umbilical/pressure control unit. The leak was too small to fully deplete the cooling water supply. A spare unit was used on subsequent EVAs. A later investigation determined that the probable cause of the leaking was due to the connectors being exposed to the cold environment of space and a small side load being placed on the connector.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Skylab 4 | 11/22/1973 | EVA: 1
During the November 22nd EVA, the crew members experienced difficulty keeping their suit umbilicals separated. This cost them time and effort to keep the umbilicals under control and could have presented a risk of severe entanglement.
Source(s):
Skylab 3 | 9/22/1973 | EVA: 3
During the September 22nd EVA, the airlock module suit cooling system suffered leaks and was inoperable for the EVA. The physically undemanding nature of the tasks to be completed allowed the EVA to proceed with only air cooling.
Source(s):
Skylab 2 | 6/7/1973 | EVA: 2
During the June 7th EVA, the Skylab primary EVA heat exchanger module suffered from minor clogging, but the EVA was able to continue. The clogging of the heat exchanger led engineers to design a new module that would serve as a backup. The new backup module was delivered to Skylab in July 1973 by the next crew.
Source(s):
Apollo 17 | 12/11/1972 | EVA: 1
During the December 11th EVA, one of the crew members suffered contusions to his hand while extracting a core sample. The device used to obtain the core samples became stuck, despite a design that was supposed to ease removal of the core sample. During the EVA, part of the Lunar Rover fender was broken off, but taped back in position. On the way to the first geological survey station the “repaired” fender fell off and showered the crew members with dust.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 16 | 4/23/1972 | EVA: 3
During the EVA on April 23rd, the Lunar Rover suffered a temporary navigational computer failure. The crew members used the sun’s position to determine their location, allowing them to locate the Lunar Excursion Module. An investigation later revealed that the most probable cause of the issues with the navigation system was improper wire crimps on the flight vehicle when compared with the solder connections used in the test vehicle on the ground. The improper crimps allowed the wires to loosen when exposed to cold temperatures, causing loose connections.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 16 | 4/22/1972 | EVA: 2
During the EVA on April 22nd one crew member’s Portable Life Support System radio antenna struck the Lunar Excursion Module’s hatch frame, breaking off a portion of the antenna. The damage to the antenna caused a small drop in signal strength, but the EVA was allowed to continue.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 16 | 4/21/1972 | EVA: 1
During the April 21st EVA, one of the crew members tripped over the heat flow sensor cable connected to the Apollo Lunar Surface Experiments Package (ALSEP), tearing it loose. Mission control elected not to repair the cable on the subsequent EVA due to concern that the repair would take too much time and could possibly short-circuit the ALSEP.
One of the crew members attempted to jump and salute the flag they had placed, but slipped and fell onto the Portable Life Support System (PLSS). However, no significant damage was done to the PLSS, which remained operational.
After ingressing the Lunar Excursion Module, the crew members reported the same problems that previous flights had with the lunar dust – stuck zippers and disconnects, and scratched indicators that were difficult to read.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 15 | 8/1/1971 | EVA: 3
During the August 1st EVA, the vertical Portable Life Support System (PLSS) radio antenna snapped off of one crew member’s PLSS. The other crew member taped it back into a horizontal position. While navigating back to the Lunar Excursion Module (LEM), the crew members experienced difficulty navigating until they encountered their outbound tracks, which led them back to the LEM. An investigation later revealed that the most probable cause of the issues with the navigation system was improper wire crimps on the flight vehicle when compared with the solder connections used in the test vehicle on the ground. The improper crimps allowed the wires to loosen when exposed to cold temperatures, causing loose connections.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
Apollo 15 | 7/31/1971 | EVA: 2
During the July 31st EVA, while driving the Lunar Roving Vehicle, the front steering failed. The crew member driving was able to steer the rover with only the rear steering. Also during the EVA, one of the crew members’ drink bags failed to operate, causing the crew member to become dehydrated. After completing the EVA, the crew members discovered that the abrasive lunar dust made the Portable Life Support System (PLSS) connectors tight and difficult to operate. In addition, the crew members also experienced pain in their fingers caused by their fingernails pressing against their glove fingertips.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
STS-51I | 9/1/1985 | EVA: 2
During the September 1st EVA when the EVA crew members were handling a satellite from opposite sides, a lack of sight between them hindered visual cues and posed a potential threat of collision with Space Shuttle Discovery. The lack of visual cues caused the EVA crew members to impart opposite motions into the satellite.
Also during the EVA, one of the EVA crew members became very cold and shut off water flow to his Liquid Cooling and Ventilation Garment. With the water flow turned off, the crew member’s Extravehicular Mobility Unit (EMU or spacesuit) helmet began to fog.
Prior to the EVA the lithium hydroxide canisters used during the previous EVA to scrub carbon dioxide from the EMU were inadvertently placed back into the EMUs instead of being changed for new canisters.
Source(s):
STS-41C | 4/11//1984 | EVA: 2
During the April 11th EVA, one of the crew members experienced a minor urine containment anomaly, but the Liquid Cooling and Ventilation Garment (LCVG) absorbed most of the leakage. The crew member also noticed some helmet fogging. The fogging was due to adjustments made to the flow of cooling water to the LCVG when the crew member became too cold.
Source(s):
STS-41C | 4/8//1984 | EVA: 1
During the April 8th EVA, hardware configuration differences prevented the EVA crew member from capturing a satellite as planned. A grommet, which was on the satellite but did not appear in the blueprints, prevented the Trunnion Pin Attachment Device jaws from closing onto one of the satellite’s berthing docking pins. The failed attempts caused the satellite to lose sun-lock and begin to tumble. The EVA was forced to end early when readings indicated that the Manned Maneuvering Unit nitrogen propellant supply was low.
Source(s):
STS-41B | 2/7/1984 | EVA: 1
During the February 7th EVA, one of the quick-release pins (pip-pin) pulled free from the bracket used to secure the EVA slidewire, which allowed crew members to freely move in the payload bay while remaining safely tethered to the shuttle. The most probable cause of the pip-pin pulling free was an inadvertent pull on the push-pull type t-handle, possibly from an EVA tether, which would unlock the detent balls holding the pin in place and release it from the bracket.
Source(s):
David F. Portree and Robert Trevino, Walking to Olympus
STS-96/2A.1 | 5/27-6/6/1999
During the flight of STS-96, the Simplified Aid for EVA Rescue (SAFER) NASA Standard Initiator (NSI) inadvertently fired sometime between May 27th and June 6th. The event likely happened either as crew members were egressing the airlock or after the EVA when removing the SAFER. The firing of the NSI resulted in the pyrotechnic isolation valve opening, causing a loss of gaseous nitrogen. Post-EVA checkouts were not part of the planned post-EVA operations, so the anomaly was not noticed until ground inspections occurred following the flight. The anomaly would have had minimal, if any, impact on the crew member’s ability to perform self-rescue during an EVA, because of the low observed leakage rate through the SAFER thrusters. If a worst-case leak rate happened on all thrusters before an EVA, a very low amount of gaseous nitrogen might have been left at the end of the EVA, which could have compromised the ability to perform self-rescue if required.
Source(s):
STS-86 | 10/1/1197 | EVA: 1
A SAFER pyro failed to fire during the SAFER developmental test objective (DTO). The pyro valve failure was not discovered until a post-flight inspection of the SAFER hardware, since the DTO was performed with the crew member in a foot restraint. The failure triggered an investigation into the pyro and the redesign of the pyro system. Had this failure occurred during a self-rescue, the crew member would have been lost due to the latent design issue.
Source(s):
STS-80 | 11/29/1996 | EVA: 1
The November 29th EVA was terminated before the EVA crew members could leave the airlock. They were unable to unlatch the outer airlock hatch. Post-flight inspection determined that the failure was caused by a loose screw lodged within the hatch actuator mechanism gears.
Source(s):
STS-63 | 2/9/1995 | EVA: 2
The February 9th EVA was terminated early after the crew reported experiencing “level 3”cold (“unacceptably cold”) on a 1 to 8 scale created before launch.
After the EVA, when one crew member removed their helmet, the crew member noted an odor and suffered burning eyes. An air sample was taken, and the crew member washed their eyes with water. Post-flight analysis revealed no contaminants, and the most likely cause was contact with the anti-fogging soap solution.
Source(s):
STS-61 | 12/5/1993 | EVA: 2
During the December 5th EVA, one of the EVA crew members experienced difficulty receiving radio communications from Space Shuttle Endeavour and the ground. The other EVA crew member served as a relay, instead of the first crew member switching to a backup that would prevent downlinking of biomedical data to the ground.
Source(s):
STS-57 | 6/25/1993 | EVA: 1
During the June 25th EVA, while the EVA crew members were away from the payload bay and oriented toward space, they became cold enough to start shivering and experienced numbness and pain in their hands.
Also during the EVA, an untethered piece of Inertial Upper Stage tilt table equipment was almost lost, but was retrieved by one of the crew members.
Source(s):
STS-37 | 4/8/1991 | EVA: 2
After the April 8th EVA, the second consecutive EVA on STS-37, the exhausted EVA crew members recommended against performing future EVAs on consecutive days because of time constraints and fatigue.
Source(s):
STS-37 | 4/7/1991 | EVA: 1
During post-flight inspection it was discovered that the palm bar in the right hand glove worn by one crew member had shifted and punctured the restraint and glove bladder. It was determined that the palm bar was in an incorrect position due to insufficient restraints in the palm restraint tunnel allowing it to penetrate through a non-reinforced area of the palm restraint strap tunnel. To prevent recurrences of this anomaly, the palm bar strap was modified with stitching to prevent the bar from moving within the tunnel.
Source(s):
STS-128/17A | 9/5/2009 | EVA 3
During the September 5th EVA, the Extravehicular Mobility Unit (EMU or spacesuit) camera and light detached from the EMU helmet. The camera and light were prevented from floating away by the electrical cable, mitigating a risk for collision with ISS.
Source(s):
JKO EVA history STS-128 EVA 3
STS-127/2JA | 7/22/2009 | EVA 3
During the July 22nd EVA, the crew members’ high metabolic rates exceeded the design limitations of the Extravehicular Mobility Unit (EMU or spacesuit) carbon dioxide scrubbing system, resulting in one of the EVA crew members experiencing elevated carbon dioxide levels. The EVA was terminated after only two of four new ISS batteries had been installed, leaving the ISS in a configuration with limited operational capability.
Source(s):
STS-125/HST | 5/17/2009 | EVA 4
Near the end of the May 17th EVA, a tear in the palm bar of one EVA crew member’s Extravehicular Mobility Unit (EMU or spacesuit) glove triggered an early termination. Because the termination happened during the cleanup phase of the EVA, there were no additional operational impacts.
Source(s):
JKO EVA history STS-125 EVA 4
STS-126/ULF2 | 11/24/2008 | EVA: 4
The November 24th EVA was terminated as the crew members were entering the airlock at the end of the EVA after one of the EVA crew members experienced higher than acceptable levels of carbon dioxide.
Source(s):
STS-126/ULF2 | 11/20/2008 | EVA: 2
The November 20th EVA was terminated early after one of the EVA crew members experienced higher than acceptable levels of carbon dioxide. Once the crew member had returned to the airlock, the carbon dioxide returned to acceptable levels.
Source(s):
https://wiki.jsc.nasa.gov/eva/index.php/STS-126/ULF-2_EVA_2
STS-120/10A | 10/30/2007 | EVA: 3
After the October 30th EVA, one Extravehicular Mobility Unit (EMU or spacesuit) was deemed unusable due to a degraded sublimator. The sublimator water outlet temperature was higher than expected and had been trending upward on two prior EVAs. After the EVA the EMU was declared unusable for additional planned EVAs. Prior to the failure, the sublimator was used for STS-115 and STS-117 and had also shown high exit temperatures during those EVAs.
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STS-118/13A.1 | 8/15/2007 | EVA: 3
The August 15th EVA was terminated early per flight rules after a small hole was discovered in the Vectran layer of on crew member’s glove during a routine glove check between tasks. The cause of the glove damage was unable to be determined after an extensive review of the video from the EVA.
Source(s):
https://wiki.jsc.nasa.gov/eva/index.php/STS-118/13A.1_EVA_3
STS-116/12A.1 | 12/26/2006 | EVA: 1
During the December 12th EVA, one crew member’s Simplified Aid for EVA Rescue (SAFER) Hand Controller Module (HCM) inadvertently deployed during airlock egress. The other EVA crew member re-stowed the HCM on the second attempt. The inadvertent deployment of the HCM caused the SAFER NASA Standard Initiator, or pyro, to accidently fire, which pressurized the SAFER thrusters and could have led to an inadvertent firing of the thrusters inside the airlock. The on-board spare SAFER was used for the subsequent EVAs. Flight rules were established after this flight for the crew to check the status of the SAFER after EVA if the HCM was inadvertently deployed.
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STS-121/ULF1.1 | 7/10/2006 | EVA: 2
During the July 10th EVA, left side upper latch of one crew member’s Simplified Aid for EVA Rescue (SAFER) came unlatched, resulting in it disengaging from the Extravehicular Mobility Unit (EMU or spacesuit). The EVA was suspended until the SAFER could be secured by the other crew member to prevent losing the SAFER unit. The unlatching was attributed to accidental contact with the latch in a tight working space, and Kapton tape was used on the subsequent EVA to make sure the SAFER latches remained closed.
Source(s):
ISS Exp-9 | 5/19/2004 | U.S. EVA Ops
During pre-EVA checkout operations on May 19th, an anomaly occurred with the Extravehicular Mobility Unit (EMU or spacesuit) cooling loop. The cause of the failure was contamination in the cooling water, which caused the EMU water pump rotor to jam. The failure resulted in the loss of U.S. EVA capability aboard the ISS until November 2005. Analysis performed on hardware returned to the ground helped to develop a process to maintain the on-orbit system. The process involves using a filtration system before and after EVA operations to maintain the quality of the loop coolant and to clean the EMU coolant water before storage.
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STS-100/6A | 4/24/2001 | EVA: 3
During the April 24nd EVA, one of the EVA crew members experienced two instances of eye irritation similar to what was experienced on the prior EVA. The crew member observed that water escaped from the in-suit drink bag and was floating near the visor. The eye irritation was likely caused by water from the in-suit drink bag leaking and contacting the helmet visor and then the crew member’s eyes. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
STS-100/6A | 4/22/2001 | EVA: 2
During the April 22nd EVA, one of the EVA crew members experienced an irritation in one eye and was told to perform a helmet purge to clear any particulates. The purge did not help the irritation, which eventually spread to both eyes. Approximately 30 minutes later the irritation began to subside due to natural eye tearing. The irritation was believed to have been caused by water from the in-suit drink bag leaking and contacting the helmet visor and then the crew member’s eyes. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
STS-98/5A | 2/10/2001 | EVA: 1
During the February 10th EVA, one of the EVA crew members was sprayed with ammonia from a leaking connector (quick disconnect). The EVA crew completed suit decontamination procedures prior to ingressing the airlock. These procedures consist of the crew members staying in the sun for a period of time, also known as a “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
STS-97/4A | 12/3/2000 | EVA: 1
During the December 3rd EVA, one of the EVA crew members coughed shortly after taking a sip of water. This caused liquid to bounce off the helmet visor, landing in the crew member’s right eye and causing a burning sensation. The crew member was instructed to ingress the airlock and purge the helmet to remedy the irritation. The cause of the eye irritation is believed to be the anti-fog agent used inside the helmet. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
U.S. EVA 46 | 10/20/2017
During U.S. EVA 46 the SAFER was inadvertently activated. A SAFER checkout was performed after the EVA which confirmed that the pyro valve had fired during the EVA and resulted in the depletion of the nitrogen gas tanks. No rescue capability exists after depletion. In this case a crew member who inadvertently detached would have had no self-rescue capability.
Source(s):
U.S. EVA 42 | 5/12/2017
ISS Increment 51: During U.S. EVA 42 the ISS EMU Service and Cooling Umbilical (SCU) leaked during the EVA pre-breathe, causing a "softball sized" water bubble. Flight rules allow the crew member to go EVA with only one SCU available, but that means one crew member has to depressurize and repressurize without cooling and EVA duration may have to be shortened due to more time on battery power during depress. The crew reported almost unbearable temperatures during depress. In the event of an early EVA termination when no cold-soak time is available, crew members may be exposed to extreme temperatures during repress as well when only one SCU is available. The SCU was redesigned with strain relief to avoid future leaks and reduce the likelihood of one level of cooling capability being unavailable at the start of an EVA.
Source(s):
US EVA 42 S/G Debrief Transcript – FINAL
(Restricted Access – contains PII (personally identifiable information) protected under the Privacy Act of 1974, as amended)
U.S. EVA 41 | 3/30/2017
During U.S. EVA 41, helmet lights detached from the helmet, but were held captive by the electrical cable. This is a recurrence of an event in September 2009. This failure could have impaired the crew member’s ability to perform nominal and emergency tasks, such as rapid emergency ingress during insolation.
Source(s):
U.S. EVA 38 | 1/6/2017
During U.S. EVA 38, EV2’s right glove was used in a hammer-like motion to free a work light. Ground teams could not determine whether the glove had been internally damaged, so the gloves were restricted from further flight use (downgraded to class C) after the EVA.
Source(s):
U.S. EVA 35 | 1/15/2016
The January 15th EVA was terminated early after water was observed in one EVA crew member’s helmet. The Extravehicular Mobility Unit (EMU or spacesuit) used for the EVA was the same one which had experienced previous water-in-helmet anomalies on EVAs 22 and 23. After this incident the EMU was declared unusable for future EVAs. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
NASA making progress on EVA-35 water leak incident _ NASASpaceFlight.com
U.S. EVA 32 | 10/28/2015
During depressurization for U.S. EVA 32, the feedwater switch of EMU 3010 was inadvertently switched on prior to the airlock being at vacuum. This allowed water to flow into the sublimator prior to the airlock environment reaching the triple point of water, which could have caused significant damage to the sublimator, resulting in loss of cooling capability and possible internal and external water leaks posing a hazard to the crew member. Subsequent failure or inability to quickly return to the airlock could lead to loss of crew. The EVA proceeded, but flight rules were subsequently updated to document that an inadvertent feedwater switch activation prior to 0.5 psia requires EVA termination.
Source(s):
U.S. EVA 25 | 12/24/2013
During the December 24th EVA, the EVA crew members experienced difficulty disconnecting ammonia fluid lines and reported seeing ammonia flakes escaping a valve while disconnecting the lines. The quick-disconnect button on the valve could not be pushed, requiring the crew to use a tool called the Bail Control Tool, that had been developed after previous issues with quick disconnects. The crew successfully demated the quick disconnect, replaced the failed Pump Module, and completed the necessary suit decontamination procedures before entering the ISS. The decontamination procedures consist of the crew members staying in the sun for a period of time prior to ingressing the airlock, also known as a “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
ISS Expedition 38 US EVA 25 Updates - Spaceflight101
U.S. EVA 24 | 12/21/2013
After returning to the airlock at the end of the December 21st EVA, one crew member accidentally actuated the Extravehicular Mobility Unit’s (EMU’s or spacesuit’s) Feedwater Switch for 2-3 seconds. Water flooded the sublimator, which can cause irreparable damage to the EMU, and the suit was declared unusable for EVA until proper drying procedures were performed.
Source(s):
U.S. EVA 23 | 7/16/2013
On July 16th about 44 minutes into the EVA, one crew member reported water in the helmet of the Extravehicular Mobility Unit (EMU or spacesuit). The EVA ground team and the crew member were unable to determine the source of the water. While the EVA continued, the amount of water in the helmet increased and eventually migrated from the back of the crew member’s head to his face. Approximately 1 to 1.5 liters of water had entered the EMU’s ventilation loop and collected in the EMU helmet. At this point the EVA was terminated and the crew member was able to find the way back to the airlock, despite the water obscuring his vision. All EVA crew members safely entered the airlock and re-pressurized.
Source(s):
Suit Water Intrusion Mishap Investigation Report
U.S. EVA 22 | 7/9/2013
During the August 30th EVA, telemetry sent back to the ground controllers indicated that one of the Extravehicular Mobility Units (EMUs or spacesuits) was experiencing an unexpected cooling water temperature increase. Following the EVA the EMU suit was declared unusable for future EVAs and returned to Earth for investigation. The investigation determined that the cause of the temperature increase was a degradation in sublimator performance due to contamination from an unknown source.
Source(s):
Suit Water Intrusion Mishap Investigation Report
U.S. EVA 18 | 8/30/2012
During the August 30th EVA, telemetry sent back to the ground controllers indicated that one of the Extravehicular Mobility Units (EMUs or spacesuits) was experiencing an unexpected cooling water temperature increase. Following the EVA the EMU suit was declared unusable for future EVAs and returned to Earth for investigation. The investigation determined that the cause of the temperature increase was a degradation in sublimator performance due to contamination from an unknown source.
Source(s):
STS-134/ULF6 | 5/25/2011 | EVA: 3
During the May 25th EVA, one of the EVA crew members experienced eye irritation. The most probable cause was the helmet anti-fogging agent. Irritation to the crew member’s eyes during an EVA can causing tearing, resulting in the tears collecting around the eyes and impairing vision.
Source(s):
Realtime coverage of STS-134 EVA No. 3
STS-134/ULF6 | 5/20/2011 | EVA: 1
Near the end of the May 20th EVA, one of the EVA crew members received the “Carbon Dioxide Sensor Bad” message. Because of the failure of the carbon dioxide sensor, the EVA was terminated early. The most likely cause of the failure was high humidity in the vent loop due to high oxygen use rates, along with the EVA taking place in a cool thermal environment. The sensor was dried out prior to the next EVA and functionality was restored.
Source(s):
Realtime coverage of STS-134 EVA No. 3
U.S. EVA 16 | 8/11/2010
During the August 11th EVA, one of the EVA crew members was exposed to ammonia from a leaking connector (quick disconnect) and experienced difficulty actuating the quick disconnect. The quick disconnect was eventually de-mated successfully, allowing for the subsequent removal and replacement of the failed coolant pump. Because the amount of leaking ammonia was small, the time required to finish the EVA allowed the ammonia to sublimate off the suit and decontamination procedures were not required at the end of the EVA.
Source(s):
CBS News Space Place - Space News ISS-24
U.S. EVA 15 | 8/7/2010
During the August 7th EVA, one of the EVA crew members was exposed to ammonia from a leaking connector (quick disconnect) and experienced difficulty actuating the quick disconnect. The EVA crew completed suit decontamination procedures prior to ingressing the airlock. These procedures consist of the crew members staying in the sun for a period of time, also known as “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
STS-130/20A | 2/17/2010 | EVA 3
During the February 17th EVA, large water droplets were observed in one EVA crew member’s helmet. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
STS-130/20A | 2/14/2010 | EVA 2
During the February 14th EVA, one crew member was exposed to ammonia from a leaking connector (quick disconnect). The EVA crew completed suit decontamination procedures prior to ingressing the airlock. These procedures consist of the crew members staying in the sun for a period of time, also known as a “bakeout.” The ammonia used in the ISS External Thermal Control System poses a serious health risk (eye/throat irritation, inflammation of the respiratory tract, or death) if allowed to enter the ISS habitable area.
Source(s):
STS-130/20A | 2/1/2010 | EVA 1
During the February 11th EVA, one of the EVA crew members noticed water in the Extravehicular Mobility Unit (EMU or spacesuit) helmet and in the EMU boots. Excessive water in the suit presents a hazard to the crew member’s vision, hearing, and breathing.
Source(s):
JKO EVA history STS-130 EVA 1
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