Value chain · CLM-1220
In plain terms
The receiving site sends a guide signal up to the satellite, and the satellite's many small transmitters use it to line up their beams on that site. The design uses 2.45 GHz microwaves.
The claim as recorded
SPS-ALPHA's transmitter is a retrodirective phased array: its many RF elements are made coherent by a pilot signal sent from the receiver site. All three cases in Table 7-16 (18 MW, 500 MW and 2,000 MW delivered) transmit at 2.45 GHz.
Evidence behind this: The concept author's own NIAC Phase 1 report; design choices, not test results.
Scope and limits
DESIGN CHOICES IN A PRELIMINARY STUDY. The retrodirective method "has already been proven at low TRL in several field tests" (PDF 20), not at SPS scale. Beam width and rectenna size are not given on these pages. The 2,000 MW case is Case_4B (CLM-0188 (low confidence)); the mass statement of CLM-1218 is Case_1.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF 20, raw: "SPS-ALPHA incorporates the concept of the retrodirective phased array, which allows a large number of individual RF elements to be controlled and their transmissions made coherent through the use of a "pilot signal" transmitted from the site of the planned receiver." PDF 83, Table 7-16, raw: "Power Delivered to Earth 18 MW 500 MW 2,000 MW WPT Transmission Freq. 2.45 GHz 2.45 GHz 2.45 GHz", for "DRM 3 / Case 1", "DRM 4 / Case_1" and "DRM 5 / Case_4B".
Basis: transmission frequency (GHz); beam control method
Cite this
energyaperture.com/c/clm-1220
CLM-1220, Energy Aperture, as of 2012-09.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-027
- CLM-0188 (low confidence)A 2012 NASA-funded concept study shows its own cost estimate falling from about $3.26 per kWh for a small near-term system down to about 9...CLM-1218SPS-ALPHA's design catches sunlight with a few thousand units of large, thin plastic-film mirrors. The mirrors are grouped into several...CLM-1219 (low confidence)SPS-ALPHA's mirrors concentrate sunlight about three times on the array. The report estimates that five times would save almost 15,000...CLM-1321The 2012 design study for SPS-ALPHA put the weight of its 2 gigawatt satellite at about 35,000 tonnes, about half of it in the transmitter.