Peter_GST: Gravity Space Technologies (GST) station (2025)

Design summary

v1. r = 42 m, 3.5 rpm, 0.61 g. The ring supports non-rotating microgravity R&D and manufacturing sections, because "AG alone has no near-term business case" Peter_GST, 2025-04-10.
All modules fit the Starship payload envelope, with structural simulations for axial and lateral loads.
LEO 450 km, i = 23.4°, inertial, spin axis normal to the ecliptic; altitude boosts every ~50 days tied to J2 nodal-regression reset.
A 1:72 printed model of a 30k-component CAD; gravity-space-technologies.com.
Mechanics. The ring is mechanically decoupled via bearings and 2 motors and rotates about its max-inertia axis. Heavy structure; water ballast; CMG attitude control. The ring is edge-on to the sun with PV outside and radiators inside Peter_GST, 2025-04-11; Peter_GST, 2025-04-13.
Business. A 50-page business plan with 7-year financials Peter_GST, 2025-04-13.
Escape. Dragon capsules as escape vehicles; "plan C" dumb lifeboat modules Peter_GST, 2025-04-13; Peter_GST, 2025-04-14.
Stability outcome. The rigid-body z MoI ratio is only 1.05. The High Frontier dual-spinner model gave 1.54 with ring "soil depth", but with soil depth 0 the ratio is 0.99: a potential catastrophic failure mode. Peter_GST called it a "bad design" and shelved it Peter_GST, 2025-04-20; Peter_GST, 2025-04-21; Peter_GST, 2025-04-21.
rev2 (Aug 2025): the two industrial modules were reduced and moved in Peter_GST, 2025-08-31.

"1": the real danger is a mass offset shifting the rotation axis off the wheel centre, pulling on the industrial section so it flexes like a bow 1, 2025-04-14.
Coastal Ron: a non-rotating section coupled via a bearing transmits wheel tilt; W:D:H near 1:1 is dangerous Coastal Ron, 2025-04-14.
Paul451: the pull is circular and induces rotation of the "non-rotating" section; long-axis instability Paul451, 2025-04-15.
A non-rotating hub on a bearing vibrates unless perfectly balanced Peter_GST, 2025-04-11.

Peter_GST, 2025-04-10 (reply #4844, 5 likes): GST station (5 likes). Post.
Peter_GST, 2025-04-11 (reply #4850): Mechanics. Post.
Peter_GST, 2025-04-13 (reply #4856): Detail. Post.
Peter_GST, 2025-04-13 (reply #4858): Business plan. Post.
Peter_GST, 2025-04-13 (reply #4861): Escape. Post.
Coastal Ron, 2025-04-14 (reply #4866): Bearing transmits tilt. Post.
Peter_GST, 2025-04-14 (reply #4872): Plan C. Post.
1, 2025-04-14 (reply #4876, 2 likes): Mass offset danger (2 likes). Post.
Paul451, 2025-04-15 (reply #4877, 1 like): Induced rotation. Post.
Peter_GST, 2025-04-20 (reply #4887): Stability outcome. Post.
Peter_GST, 2025-04-21 (reply #4888, 1 like): Ratio 0.99. Post. Attachments: pures.jpg, pure2s.jpg, pure3s.jpg.
Peter_GST, 2025-04-21 (reply #4889, 1 like): Shelved. Post.
Peter_GST, 2025-08-31 (reply #4928, 3 likes): rev2 (3 likes). Post. Attachments: GST01_rev2_small.jpg.