Value chain · CLM-0441
In plain terms
A normal geostationary satellite needs a small, regular fuel-based nudge every year to stay in place. One 2019 design proposes cutting most of this fuel need for a solar power satellite by placing it in an orbit tilted by about 8 degrees that resists being pushed off station, and keeps the satellite pointing the right way passively using its symmetric shape and sunlight pressure.
The claim as recorded
Conventional geostationary satellites typically require about 50 m/s of delta-v correction per year for station-keeping against lunar and solar gravitational perturbations; the CASSIOPeiA concept states that a high area-to-mass-ratio satellite such as an SPS also has to contend with photon pressure, and proposes a Laplace plane orbit, which it says is "highly resilient to perturbation, requiring minimal (if any) station-keeping propellent", as its alternative for station-keeping to the active-thruster approach in CLM-0330 to CLM-0332; separately, for attitude, it uses a rotationally symmetric mass distribution that minimises gravity-gradient torque and a small sun-facing reflective area forward of the centre of mass whose photon pressure gives a restoring torque.
Scope and limits
A design PROPOSAL, not a flown or fully modelled result; the paper does not quantify a residual propellant requirement (if any) for the passive approach, so it cannot be compared in kg/year terms to CLM-0330/0331.
What it assumes
The "~50 m/s/yr" figure is presented as general background knowledge about conventional GEO satellites, not derived or cited to a specific reference in the excerpt read.
Where it comes from
printed p.177 (PDF 8): "Geostationary satellites require around 50 m/s Delta-v correction per year to maintain station-keeping in the presence of perturbations; principally lunar and solar gravitational effects. A high area-to-mass ratio satellite such as an SPS also has to contend with photon pressure..."; printed p.175 (PDF 6): "a small (in-proportion) additional sun-facing reflective area forward of the system centre of mass provides passive stability; any angular misalignment error tends to be corrected by the restoring torque generated...". Printed p.177 (PDF 8): "Laplace plane orbits are highly resilient to perturbation, requiring minimal (if any) station-keeping propellent [15]" ("propellent" is the page's spelling). Printed p.174 (PDF 5): "Having a rotationally symmetric mass distribution minimises microgravity torsional effects" (ligature fold). Printed p.177 (PDF 8), the sentence after the Laplace plane sentence, says the precise orbital inclination (printed as 7.7 to 8.7 degrees) "can be chosen according to the SPS's Sun-facing area/mass ratio", to minimise the effect of photon pressure.
Basis: delta-v per year, m/s, conventional GEO satellite baseline
Related records
- Answers question
- QST-002 not published in this release
- Supersedes
- CLM-0335 not published in this release
Cite this
energyaperture.com/c/clm-0441
CLM-0441, Energy Aperture, as of 2019.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-026
- CLM-0004The author of the 2019 CASSIOPeiA paper states the beam's strongest point is about 230 watts per square metre, and says that figure was...CLM-0006None of the five main studies mentions the international radio-frequency exposure limits, or any safety standard, or a restricted area...CLM-0013The paper that modern UK studies rely on for the beam figure calls anything below 1 kilowatt per square metre safe, with 230 watts per...CLM-0336Different design studies over four decades have each simply assumed a different working lifetime for a solar power satellite, from about 15...CLM-0339A 2019 paper said solar power satellites are often assumed to need visits in orbit for repairs and refuelling, but that no system yet...CLM-0504None of the main CASSIOPeiA-related documents in the register mentions any named safety or exposure standard, or describes any restricted...CLM-0660The 2019 CASSIOPeiA paper does not discuss electric propulsion for getting the satellite to its orbit. It only prices delivery using...CLM-1175The design would control its orientation without fuel. Small mirror panels near its front carry a coating whose reflection can be changed...More on the source page.