Value chain · CLM-1458
In plain terms
The 2019 paper behind CASSIOPeiA's 1 kW/kg figure lists six modelled design variants, and only the two with the most concentrated sunlight reach that figure; the other four come in at 0.79 to 0.95 kW/kg. The paper does not show where the mass goes, and its statement that the design's operating principle was independently validated cites nothing and does not say what the check covered.
The claim as recorded
Ian Cash's 2019 CASSIOPeiA paper tabulates AC power and mass for six design variants, three levels of sunlight concentration in each of two orbits (Table 2, geosynchronous Laplace plane; Table 3, equatorial medium Earth orbit), which give 0.79 to 1.02 kW/kg when "Power (MWAC)" is divided by "Mass (T)"; only the two 4-sun solid-state symmetrical concentrator variants, one in each orbit, reach 1 kW/kg, and the other four give 0.79 to 0.95 kW/kg. The paper prints no subsystem mass breakdown for any variant. It attributes its 1 kW/kg figure to "detailed and conservative modelling" of a 2 GWAC variant of 2,000 T, and the sentence before that, "The operating principle of CASSIOPeiA has been independently validated by the University of Strathclyde, UK", carries no reference marker and does not say what the validation covered.
Scope and limits
All six figures are the designer's modelled values for unbuilt variants, and the paper does not say whether the masses are dry or include propellant. Later figures from the design's own team are for other variants and scales, not like-for-like updates of these tables: the designer's 2023 slides give the 4-sun variant as approaching 1 MW per tonne, the 2-sun planar as approaching 800 kW per tonne and the 1-sun as approaching 660 kW per tonne (SRC-590, PDF p.32), and a 2025 report by Frazer-Nash, Space Solar Engineering and Imperial College lists, as the makers' claimed values, 0.67 kW/kg for Space Solar's 650 MW large-scale design based on CASSIOPeiA, in geostationary orbit and available from 2040, and 0.58 kW/kg for its small-scale design (SRC-076, PDF p.11 and Table 1 on PDF p.12; PDF p.3). A subsystem mass breakdown for a de-risked CASSIOPeiA-derived variant, from Frazer-Nash's 2022 study for ESA, is in CLM-0539. No document behind the validation sentence was found among the sources held as of 2026-10-16; the held Strathclyde work is life-cycle assessment (SRC-212, SRC-016), which does not validate a design. That shows the paper names no document, not that none exists.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p.8 (printed p.177): Table 2, GLP orbital variants: 1-sun planar (quadrant) 1070 MWAC and 1350 T, 2-sun planar (full) 1470 and 1770, 4-sun SSSC 2050 and 2010; Table 3, MEO orbital variants: 688 and 866, 974 and 1020, 1310 and 1280. Power over mass gives 0.79, 0.83 and 1.02 kW/kg (GLP); 0.79, 0.95 and 1.02 kW/kg (MEO); 974 / 1020 = 0.9549. PDF p.5 (printed p.174) names SSSC as the solid-state symmetrical concentrator, modelled at 4 suns. PDF p.3 (printed p.172): the validation and modelling sentences quoted in the claim, one after the other; the same page carries reference markers [8] to [11] elsewhere, on Table 1 and the list of concept types, and none on the validation sentence.
Basis: specific power, kW/kg, from the tables' "Power (MWAC)" over "Mass (T)"; the paper does not say dry or wet mass
Related records
- Answers question
- QST-002 not published in this release
- Supersedes
- CLM-0507 not published in this release
Cite this
energyaperture.com/c/clm-1458
CLM-1458, Energy Aperture, as of 2019.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-026
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