Value chain · CLM-1409
In plain terms
A 1977 NASA study of how to hold up the receiving station's panels was told the ground underneath had to stay farmable, with a metal mesh of small diamond-shaped holes. It compared eleven ways of building it, some raised about 5 metres, high enough for farm machines underneath, and found the more usable the land below, the more the structure costs.
The claim as recorded
NASA's 1977 rectenna structure study required the ground beneath to stay usable, specified a ground plane with 1 by 2 cm openings, and found that cost rises with usable land. The study criteria included "Ground surface area covered by the rectenna is required to be usable for other purposes such as crop production" and "The groundplane will have a pattern of diamond-shaped openings 1 cm by 2 cm". Of 11 structural systems (Fig. IV-D-7), systems 5 and 6 "are elevated to provide clearance below the structure" and systems 7 to 9 "are elevated to provide clearance for vehicles or machinery to operate below the structure"; system 10 is "a series of towers". The finding: "within a limited space between columns, little cost difference exists between the different configurations. As the usability of the land increases (larger column spacing), the structural cost increases significantly." Fig. IV-D-7 dimensions systems 7 and 8 with a 16.0 ft clearance under the structure and columns 36.0 ft apart (about 4.9 m and 11.0 m, our conversion).
Evidence behind this: NASA JSC's 1977 report of a contracted structural study (Bovay Engineers, NAS9-15280); gross quantities and costs, not a detailed design.
Scope and limits
NO COST FIGURE FOR THE RAISED SYSTEMS IS QUOTED HERE: Tables IV-D-3 to IV-D-5 hold the quantities and costs and were not read. Fig. IV-D-7 was read at a render on 2026-10-09 for systems 7 and 8 only; Systems 7 and 8 are used because they are the two the figure dimensions with a clearance under a raised deck; System 9, which the text also lists as elevated for machinery, is drawn as a sawtooth 11.1 ft high overall with no clearance dimension. The 16.0 ft clearance is the study's design for vehicles and machinery in 1977, and no held source says whether it clears modern farm machinery. The drawing is a poor-quality reproduction; the dimensions of systems 1 to 6, 9 and 10 are not recorded here. The 1 x 2 cm openings are a study criterion, not a tested mesh; the optical transparency they give is not stated on these pages (CLM-1102 has 75-80% for the 1978 reference mesh). The study's site is 31 degrees latitude, with a cost rise of 20 to 45 per cent at 40 degrees.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF 156 [IV-D-16], raw: "(3) Ground surface area covered by the rectenna is required to be usable for other purposes such as crop production."; normalised (line-end hyphen kept, layer's "l" for 1): "(4) The groundplane will have a pattern of diamond-shaped openings 1 cm by 2 cm and must be electrically conductive"; "systems 5 and 6 are elevated to provide clearance below the structure. Systems 7 through 9 are elevated to provide clearance for vehicles or machinery to operate below the structure." (normalised: the layer has "c1eara~ce" for "clearance") PDF 157 [IV-D-17]: Figure IV-D-7 "STRUCTURAL SYSTEMS" (title read in the text layer; the drawings read at a render, below). PDF 158 [IV-D-18], raw: "System 10 is a series of towers"; normalised (line-end hyphen in "diff-erent" closed): "within a limited space between columns, little cost difference exists between the different configurations."; "As the usability of the land increases (larger column spacing), the structural cost increases significantly." PDF 157 [IV-D-17], Fig. IV-D-7 "STRUCTURAL SYSTEMS" (Bovay drawing), render read at zoom 2.5: System No. 7, a flat deck on columns, dimensioned 16.0' high and 36.0' between columns; System No. 8, a deck on a truss, 16.0' to the underside (the text layer garbles the drawings' labels).
Basis: structural systems (11); ground-plane opening size in cm; cost against column spacing
Related records
- Answers question
- QST-007 not published in this release
Cite this
energyaperture.com/c/clm-1409
CLM-1409, Energy Aperture, as of 1977.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-549
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