Value chain · CLM-0023
In plain terms
In the 1978 reference design, two limits set the size of the transmitter and the receiving site: how much heat the transmitter can shed, and an upper limit on beam strength taken from studies of the ionosphere.
The claim as recorded
The 1978 Reference System sizes its transmit antenna and rectenna from two limits: a thermal dissipation limit of approximately 21 kW/m2 on the transmit antenna, and the 23 mW/cm2 ionospheric beam limit, which together with a desired rectenna power output fix the transmit antenna and rectenna diameters.
Scope and limits
Applies to the 1978 reference architecture. Later architectures may size differently, and CASSIOPeiA in particular claims near-invariant areal power density, which may change the relationship.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
Verbatim, SRC-085 p124: "Thermal dissipation limits set a heat density value on the transmit antenna of approximately 21 kW/m2. For the operating frequency of 2.45 GHz, studies have indicated that the power density of the SPS beam should not exceed 23 mW/cm2. ... With these two limits, and a desired value of power output at the rectenna, transmit antenna size and rectenna size can be traded."
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0023
CLM-0023, Energy Aperture, as of 1978.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-085
- 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-0020The original 1978 design set the beam at 230 watts per square metre in the middle of the receiving site, about one twenty-third of that at...CLM-0039The 1978 report set the figure to protect radio and navigation systems from a disturbed ionosphere, called the number theoretical and...CLM-0045The apparent conflict between 12 and 23 was not an error. The underlying study gave a range, and the figure adopted sits near the top of it.CLM-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0137In four major space solar power studies from 1978 to 2007, none put a number on how much of the beam's energy would be lost if the beam...CLM-0138The original 1978 government design for beaming power down from space adds up all the expected energy losses to get 63% overall efficiency...CLM-0182When two different research teams assessed the exact same 1978 space solar power design, the older accounting method (which spreads...More on the source page.