Value chain · CLM-1203
In plain terms
Caltech's receiving station on the ground is a circle about 1.6 kilometres across, just large enough to catch the whole central spot of the beam. Batteries keep its output steady through the short eclipse seasons and the dips while the craft turn.
The claim as recorded
The Caltech space solar power design (CSSPS) sizes its ground rectenna to the first null of the beam's Airy disk, a diameter of 1,637 m, and assumes base-load operation with batteries covering the equinox eclipse periods, angle-dependent output and the modules' "bi-daily" manoeuvres.
Scope and limits
A DESIGN FIGURE. A rectenna sized to the first null catches the main lobe only, so the collection efficiency is bounded by that choice (the paper's own "illumination efficiency at the ground station" is 83.8%, Table 1, PDF 6, not restated here). No site, land area or rectenna element design is given on this page; the paper defers the rectenna array to its references.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF 6: "It has diameter Dg = 1,637 m: sized to the first null of the beam's Airy disk. We assume the system operates as a base-load and provides the grid with constant power. The system thus uses batteries to compensate for dark periods during predictable vernal/autumnal equinoxes, variable angle-dependent output power, and bi-daily module maneuvers". The text layer gives "1; 637 m"; read at zoom 5 from the crop named in src. Own check: 2.44 x 0.0300 m x 35,786 km / 1,600 m = 1,637 m, the first-null diameter at 10 GHz from GEO for the 1,600 m aperture (CLM-0296), matching CLM-0889's 1,636 m.
Basis: metres, rectenna diameter
Cite this
energyaperture.com/c/clm-1203
CLM-1203, Energy Aperture, as of 2025-05-13.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-006
- CLM-0179This 2025 paper's own numbers show that with today's technology, their space solar power design would cost about $7.78 per kWh - far more...CLM-0180The low headline cost figure in this paper depends on using a very low 2% discount rate borrowed from a US home-energy-efficiency...CLM-0181The 9.4-cents and 3.8-cents per kWh figures both depend on launch prices that do not exist yet - they are extrapolated 10 and 20 years into...CLM-0296A 2025 peer-reviewed study from Caltech modelled its own space solar power design and calculated three costs of electricity: about 778 US...CLM-0297The low electricity costs in a 2025 Caltech study rest on two assumptions among others. First, it assumes that SpaceX's Starship will in...CLM-0670Caltech has two different space-solar-power efforts. One is a paper design that assumes a normal rocket-fuel-based trip to a high orbit...CLM-1201Caltech's design has no single large structure. Many separate square craft, each 60 metres across, fly side by side in geostationary orbit...