A new orbital debris engineering model, ORDEM2000, has been developed by the Orbital Debris Program Office at NASA Johnson Space Center. The new model uses a more rigorous mathematical method to derive debris populations from observation and measurement data. It also uses a direct approach to build the debris environment. This new approach eliminates several limitations and assumptions utilized in the previous model (ORDEM96). The new model provides a better description of the current debris environment than ORDEM96 does. It is expected that ORDEM2000 will soon replace ORDEM96 as the standard model to evaluate the debris risk for the International Space Station (ISS) and for future Shuttle missions.