SRC-227

Recommendation ITU-R S.1003-2, Environmental protection of the geostationary-satellite orbit, 6 pp.

Commissioned by ITU-R. Who paid for a study is recorded because it bears on how its conclusions should be read, not because it makes them wrong.

Published claims resting on this source

• CLM-0748 The international radio standard says collisions in geostationary orbit happen at around 500 metres per second, far slower than in low orbit, so they are less catastrophic, but it also says a satellite has little chance of surviving any collision.
• CLM-0749 A 2010 international radio recommendation said the smallest object that could then be tracked in geostationary orbit was just under a metre across, against 30 centimetres in low orbit, so smaller debris up there went unseen, and it said other break-ups at that altitude had quite likely gone unnoticed.
• CLM-0750 The 2020 edition of the international debris guidelines says a retiring geostationary satellite should climb at least 235 km above its working orbit, plus an extra allowance that depends on how large and light it is, and the 235 km is made of 200 km of protected zone plus 35 km for the way gravity nudges the orbit back down.
• CLM-0751 Working the international disposal formula through by hand shows that for a very large and very light satellite the extra height it must climb at retirement is dominated not by the fixed 235 km allowance but by the push of sunlight on it, and that for anything lighter than about 8.5 kilograms per square metre facing the sun that sunlight term is the larger of the two.

Cite this