This article originally appeared in Orbital Debris Quarterly News, Volume 18, Issue 1, January 2014.

The latest version of the NASA Orbital Debris Engineering Model, ORDEM 3.0, has been released. The model is appropriate for those engineering solutions requiring knowledge and estimates of the orbital debris environment (debris spatial density, flux, etc.). ORDEM 3.0 can also be used as a benchmark for ground-based debris measurements and observations.

ORDEM 3.0 incorporates significant improvements over its predecessor, ORDEM2000, which was released in 2002. For the first time, ORDEM includes uncertainties in the flux estimates. The model includes material density classes. It has also been extended to describe the orbital debris environment from low Earth orbit past geosynchronous orbit (200 to 38,000 km altitude).

ORDEM 3.0 is based on a large set of observational data (both in-situ and ground-based) that reflect the current debris environment. These data cover the object size range from 10 µm to 1 m. Analytical techniques (such as maximum likelihood estimation and Bayesian statistics) are employed to determine the orbit populations used to calculate population fluxes and their uncertainties. The model output lists fluxes of debris in half-decade size bins by distinct material characteristics (i.e., intact objects, high-, medium-, or low-material density objects, and NaK droplets) either by direction and velocity for an encompassing ‘igloo’ (for spacecraft) or by range bins (for a sensor beam on the Earth’s surface), depending on the user’s chosen operational mode.

The program graphical user interface (GUI), executable, data files, and an ORDEM 3.0 User’s Guide are included in the package. ORDEM 3.0 has been subjected to extensive verification and validation. Currently, ORDEM 3.0 runs on Windows XP or more recent PC operating systems. Although approved for public release, NASA regulations require that a software usage agreement must be obtained to acquire a copy of the NASA-developed software, ORDEM 3.0, MSC-25457. To begin the process, please email your request to <jsc-techtran@mail.nasa.gov>.

ORDEM 3.0 was developed by NASA’s Orbital Debris Program Office (ODPO) located at Johnson Space Center, Houston, TX. Funding for the ODPO comes from NASA Headquarters’ Office of Safety and Mission Assurance.

A more detailed description of ORDEM 3.0 can be found on Page 5 of the newsletter.