ORDEM 3.1 : OD Engineering Model
The latest version of the NASA Orbital Debris Engineering Model, ORDEM 3.1, 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 3.1 can also be used
as a benchmark for ground-based debris measurements and observations.
ORDEM 3.1 uses the same model framework as its predecessor, ORDEM 3.0, which was released in 2013.
It incorporates the latest high-fidelity datasets, as well as advanced data analysis techniques to
build and validate representative orbital debris populations encompassing low Earth orbit (LEO) to
geosynchronous orbit (GEO) altitudes for the years 2016-2050.
ORDEM 3-dimensional average cross-sectional area flux for a spacecraft assessment, mapped to a 2-D directional flux projection. Hot colors indiciate areas of high flux while cool colors are areas of low flux. Direction relative to the spacecraft is noted in coordinates (local azimuth & elevation), where azimuth runs along the horizontal from left to right and ranges from -180° to 180° and elevation runs vertically from bottom to top and ranges from -90° to 90°. Credit: NASA ODPO.
Incorporated in ORDEM 3.1 is a large set of observational data (both in-situ and ground-based)
that reflects the current debris environment. This data covers the object size range from 10 µm
to 1 m. The orbital debris environment is dynamic and must be periodically updated. As newer datasets
become available, they provide both more and updated information on the evolution of the orbital debris
environment.
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. New approaches
to analyzing the available data have been implemented in ORDEM 3.1 for large historical breakup clouds, in
situ impact data, and the GEO population.
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 3.1 User’s Guide
are included in the package. ORDEM 3.1 has been subjected to extensive verification and validation.
Currently, ORDEM 3.1 runs on Windows 7 and higher computers.
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 3.1, MSC-25457. To begin the process,
please press the "Request Now!" button in the
software catalog.
ORDEM 3.1 was developed by NASA’s Orbital Debris Program Office (ODPO) located at Johnson Space
Center, Houston, TX. Funding for the ODPO comes from NASA Headquarter’s Office of Safety and
Mission Assurance.