Value chain · CLM-1181
In plain terms
A student study built with the designer's input describes a small version, about 260 metres across and as tall as it is wide, for 24 megawatts. The surface is upright at the centre and leans over towards the rim, to about a third of a right angle.
The claim as recorded
A 2022 thesis gives one CASSIOPeiA variant as a helix 261.8 m in diameter and 261.8 m high, and tilts its surface by theta = arctan(h / (r pi)). Table 2-4, "extracted from the engineering model provided by" the designer, lists 28.8 MT, 24 MW, SSO (894 km), 5.8 GHz, 0.83 kW/kg, "Concentration Factor 2 sun", "Diameter 261.8 m Height 261.8 m". The thesis assumes "a regular helicoid which means that the diameter of the helicoid is equal to its height". It quotes the designer: modules "at the axis will have their deployed plane aligned vertically with this axis. Modules at the perimeter, however, will be tilted according to the height: circumference ratio, 2: [pi]". The tilt runs from 90 deg at the axis to 32.5 deg at the rim. Its Fig. 2-10 draws the helix from two sides, as an hourglass one way and a spindle the other.
Evidence behind this: A non-peer-reviewed MSc thesis whose variant data are stated to come from the designer's engineering model and personal communication. The designer's numbers through a student.
Scope and limits
ONE DEMONSTRATOR-SCALE VARIANT, NOT THE GEO SYSTEM: 24 MW in SSO. H = D is stated as the thesis's assumption on PDF 25. It agrees with Table 2-4 and with the designer's "2: [pi]" rim tilt, which equals arctan(H / (pi R)) only when H = D. THE RIM TILT APPEARS AS 32.5, 32.7 AND 34.5 DEG. 32.5 follows from r = 130.9 m (261.8 / 2); 32.7 follows from the page's own "0 to 129.6 m (radius = 261.8/2)", a slip, and is used on PDF 33-34 (own arithmetic, 3d-02 recheck2 (d)). 34.5 labels a CAD drawing (PDF 29) and has no stated cause. The designer's quote also says "half the radius (325 metres)", which implies a 1.3 km helix, a different variant from Table 2-4 (own arithmetic). The spindle side view rests on this thesis alone; no held Cash document draws it.
What it assumes
That the tilt is the slope of the module plane from the plane normal to the axis. PDF 30 says it is "measured with reference to the twist axis"; the values, 90 deg on the axis where the plane is vertical, fix the sense (3d-02 recheck2 (d)).
Where it comes from
PDF 24 [14], raw: "These characteristics were extracted from the engineering model provided by Ian Cash during a meeting."; Table 2-4, raw: "Mass 28.8 MT Power 24 MW Orbit SSO (894 km) Frequency 5.8 GHz Specific Power 0.83 kW/kg Concentration Factor 2 sun Diameter 261.8 m Height 261.8 m". PDF 25 [15], raw: "we assume the helicoid to be a regular helicoid which means that the diameter of the helicoid is equal to its height". PDF 30 [20], raw, transliterated: "Modules situated at the axis will have their deployed plane aligned vertically with this axis. Modules at the perimeter, however, will be tilted according to the height: circumference ratio, 2: [pi]." PDF 31 [21], Eq. 2-4 read at render: theta = tan^-1(h / (r pi)); raw: "the tilt angles that were obtained were varied from 32.5[deg] on the perimeter to 90[deg] on the twist axis". PDF 26 [16], Fig. 2-10 "Helicoid Side views": left plot a spindle, right plot an hourglass, both about 260 high and +/- 130 in radius (figure reading, 3d-02 recheck2 (b)).
Basis: helix diameter and height in metres; module tilt in degrees
Cite this
energyaperture.com/c/clm-1181
CLM-1181, Energy Aperture, as of 2022.
Connected records
Other published records linked to this one. A list, not a judgement.