Debris Scattering to GEO

With regards to the Chinese test: I have not seen this being articulated in any of the websites I have seen on the subject but while LEO is indeed a very sensitive location at least for ISS, has anybody quantified how much of these debris flux would eventually migrate to GEO ? My point is that with debris of similar sizes, collision is likely to produce elements with a large angular deviation (like in neutron transport) and might produce a flux to GEO. GEO would be a problem for everybody not just the ISS or low earth orbit countries.



If one looks at this 1999 UN report, one can see that there are in fact few models that take into account both LEO and GEO and therefore I am expecting that very few have coupling between LEO and GEO models within these codes.

The LEGEND model developed at JSC seems to address this issue. LEGEND was produced...

..To continue to improve our understanding of the orbital debris environment, the NASA Orbital Debris Program Office initiated an effort in 2001 to develop a new model to describe the near-Earth debris environment. LEGEND, a LEO-to-GEO Environment Debris model, is a full-scale three-dimensional debris evolutionary model. It covers the near-Earth space between 200 and 50,000 km altitude, including low Earth orbit (LEO), medium Earth orbit (MEO), and geosynchronous orbit (GEO) regions. ... The main function of the LEGEND historical component is to reproduce the historical debris environment (1957 to present) to validate the techniques used for the future projection component of the model. The model utilizes a recently updated historical satellite launch database (DBS database), two efficient state-of-the-art propagators (PROP3D and GEOPROP), and the NASA Standard Breakup Model. .... A key element in the LEGEND future projection component is a three-dimensional collision probability evaluation model. It provides a fast and accurate way to estimate future on-orbit collisions from LEO to GEO. Since no assumptions regarding the right ascensions of the ascending node and arguments of perigee of objects involved are required, this model captures the collision characteristics in real three-dimensional physical space. It is a critical component of a true three-dimensional debris evolutionary model.

The typical projection period in LEGEND is 100 years. Due to uncertainties involved in the process (e.g., future launch traffic, solar activity, explosions, collisions), conclusions are usually drawn based on averaged results from 30 Monte Carlo simulations.

J-C Liou one of the researcher involved in the development of LEGEND explained a year ago that

The current debris population in the LEO region has reached the point where the environment is unstable and collisions will become the most dominant debris-generating mechanism in the future...Even without new launches, collisions will continue to occur in the LEO environment over the next 200 years, primarily driven by the high collision activities in the region between 900- and 1000-km altitudes, and will force the debris population to increase.

Downscatter from MEO to LEO seems to be well taken into account but I still wonder about upscattering from MEO to GEO or from LEO to GEO.