Understanding the debris population at GEO and the fate of elderly satellites

Geostationary satellites carry our TV channels, weather monitoring and communications (and military observations), and are a vital resource as we develop space technologies. Their altitude of 36000km has always suggested that the effects of debris would be small. However, in the last few months 2 geostationary satellites have literally broken apart. Furthermore, as spacecraft at GEO are too distant to de-orbit, towards the end of their operational lifetimes they are ejected out of the GEO into the so-called graveyard orbits. Here they are literally turned off and left to age. What happens to them past this point is conjecture: it is expected that they age and given the hostile space environment this itself could lead to breakup. However we are starting to expect that these spacecraft can be differentially acted upon by the solar wind, hence causing the spacecraft to start spinning. On a short timescale this could also lead to breakup.

This proposal is about identifying the constitution of the debris field at GEO and also studying the effects of radiation field on the state of elderly satellites.