Value chain · CLM-0751
In plain terms
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.
The claim as recorded
Arithmetic performed here over the IADC and ITU graveyard-orbit relation shows that the solar radiation pressure term is not a small correction for a large, light structure: across the area-to-mass range of 0.01 to 0.1 m2/kg that ITU-R S.1003-2 itself states as typical, and a reflectivity coefficient of 1 to 2, the required perigee increase ranges from 245 km to 435 km, so at the top of the source's own stated range the requirement is 1.85 times the 235 km constant; setting the radiation-pressure term equal to that constant gives Cr times A/m equal to 0.235, that is an area-to-mass ratio of 0.235 m2/kg at Cr = 1 or 0.1175 m2/kg at Cr = 2, which correspond to sun-facing areal densities of 4.26 and 8.51 kg/m2 respectively, so any structure whose sun-facing areal density falls below about 8.5 kg/m2 at Cr = 2 requires a radiation-pressure allowance larger than the entire protected-region-plus-perturbation constant.
Scope and limits
This is a sensitivity analysis of a published formula over the publishing source's own stated input range. It is NOT a finding about any SBSP design, and it may not be used to say that any proposed satellite fails, or would fail, the disposal requirement. No source held gives an aspect-area-to-dry-mass ratio for any SBSP satellite concept, so whether any design falls inside or outside the 0.01 to 0.1 range is not established here and is recorded as unevidenced. Per DN-3 this arithmetic may not support the words validated, safe, achieved, proven or demonstrated. The formula also has an alternative compliance route in SRC-226 and SRC-228 - a perigee high enough that perturbations do not return the payload to the protected region within 100 years - which this calculation does not evaluate.
What it assumes
That "areal density" here means dry mass divided by the aspect area exposed to the sun, which is the reciprocal of the A/m the sources define. It further assumes the three sources mean the same quantity by A/m, which is uncertain: SRC-227 and SRC-228 say aspect area exposed to the sun and SRC-226 says cross-section area, and for a kilometre-scale planar array in a fixed sun-pointing attitude those need not coincide. No SBSP design parameter is used anywhere in this calculation.
Where it comes from
This is the project's own working, shown in full:
Relation, from SRC-226 printed p.135: delta-H = 235 + (1000 x Cr x A/m) km, for initial eccentricity below 0.003. Stated typical range, SRC-227 printed p.4, verbatim: "(A/M will typically take a value between 0.01 and 0.1 depending upon the characteristics of the satellite.)" Reflectivity range, SRC-227 printed p.4, verbatim: "Cr : reflectivity coefficient of the satellite at beginning of life and will vary between 1 and 2 depending upon its surface characteristics". Arithmetic, four corners of the stated ranges: Cr=1, A/m=0.01 gives 1000 x 1 x 0.01 = 10, delta-H = 245 km; Cr=2, A/m=0.01 gives 20, delta-H = 255 km; Cr=1, A/m=0.1 gives 100, delta-H = 335 km; Cr=2, A/m=0.1 gives 200, delta-H = 435 km. 435/235 = 1.851. Break-even: 1000 x Cr x A/m = 235 gives Cr x A/m = 0.235; at Cr=1, A/m = 0.235 m2/kg and 1/0.235 = 4.255 kg/m2; at Cr=2, A/m = 0.1175 m2/kg and 1/0.1175 = 8.511 kg/m2.
Basis: minimum perigee increase, km; area-to-mass ratio, m2/kg; equivalent areal density, kg/m2
Related records
- Answers question
- QST-011 not published in this release
Cite this
energyaperture.com/c/clm-0751
CLM-0751, Energy Aperture, as of 2026-09-04.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-226
- CLM-0750The 2020 edition of the international debris guidelines says a retiring geostationary satellite should climb at least 235 km above its...CLM-0752ESA's 2026 report says that nothing naturally removes objects from geostationary orbit the way the atmosphere slowly clears low orbit, so a...CLM-0753ESA's 2026 report says the world is not clearing satellites out of orbit well enough, that even the usual 90 per cent success target would...CLM-0754ESA's 2026 report projects that collisions between existing pieces of debris will keep making more debris in low Earth orbit even if...CLM-0756The international space debris guidelines are advice, not law: ESA's own report says they are a starting point for national rules and...CLM-1183ESA's 2026 report counts about 960 catalogued objects in geostationary orbit at the end of 2025, about 800 of them satellites, but nearly...CLM-1188Over the past ten years, almost every satellite retiring from the geostationary belt has tried to move itself out of the way as the debris...
- Also from SRC-227
- CLM-0748The international radio standard says collisions in geostationary orbit happen at around 500 metres per second, far slower than in low...CLM-0749A 2010 international radio recommendation said the smallest object that could then be tracked in geostationary orbit was just under a metre...CLM-0750The 2020 edition of the international debris guidelines says a retiring geostationary satellite should climb at least 235 km above its...
- Also from SRC-228
- CLM-0750The 2020 edition of the international debris guidelines says a retiring geostationary satellite should climb at least 235 km above its...CLM-0756The international space debris guidelines are advice, not law: ESA's own report says they are a starting point for national rules and...