Value chain · CLM-0430
In plain terms
Each of the 228 power converters in this old design needed a radiator bigger than a tennis court just to shed its own waste heat and stay within its operating temperature band.
The claim as recorded
In the 1978 US DOE/NASA reference design, each of 228 antenna DC-DC power converters is assumed to take 5.443 MW of input power at 96% conversion efficiency, reject 218 kW of waste heat, and operate at 0 to 70 degrees C using a dedicated 322.8 m2 thermal radiator, equivalent to about 1.5 m2 of radiator per kW of waste heat rejected.
Scope and limits
This is a 1978 ASSUMED point-design specification for one subsystem module, not a measured achieved result, and not a whole-satellite thermal figure. The 0-70 degrees C operating band is specific to this converter design and should not be read as a general SBSP electronics operating-temperature limit.
What it assumes
The reference design's specific converter technology and radiator design (aluminum slotted-waveguide-adjacent radiators, per the same figure) are assumed to perform as specified; no degradation over the assumed 30-year system life is included in this figure.
Where it comes from
"DC-DC CONVERTERS - PIN 5.443 Mw/CONVERTER .96 ... POUT 5.226 Mw/CONVERTER HEAT LOSS 218 kw/CONVERTER OPERATING TEMP. - 0 TO 70 C ... TOTAL NO. CONVERTERS - 228 THERMAL RADIATOR AREA = 322.8 m2/CONVERTER" (SRC-085, PDF page 286, Figure B-13 "MPTS DC-DC Converter"). 322.8 m2 / 218 kW = 1.48 m2/kW (arithmetic derived from the figure, not stated verbatim in the source).
Basis: per-unit figures for one DC-DC converter module in the 1978 reference 5 GW photovoltaic point design; 228 such converters are assumed in the full antenna
Related records
- Answers question
- QST-002 not published in this release
- Supersedes
- CLM-0205 not published in this release
Cite this
energyaperture.com/c/clm-0430
CLM-0430, 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-0023In the 1978 reference design, two limits set the size of the transmitter and the receiving site: how much heat the transmitter can shed...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...More on the source page.