LMT: Richie-class ITS/BFS stations, Terrestation and Deimostation (2018–2023)

Design summary

  • ITS 1 g station (2018). 2 ITS cargo ships (150 t of water each) + 2 crewed ITS + a free-flying telescoping hub, giving a 200 m diameter and 1 g at 3 rpm. It has >90% GCR shielding with a ≥40 cm water cushion LMT, 2018-07-13.
  • Hub: water resistojets, a JWST-type Telescopic Tubular Mast (Ti, ~4 MN × 2), Dextre-class telerobotics, <20 t. "First spin-up conceivable circa 2022" LMT, 2018-07-16.
  • It could supplant the Lunar Gateway by moving to a lunar halo orbit LMT, 2018-07-16.
  • "Richie-class" stations for concurrent AG tests LMT, 2018-07-31; LMT, 2018-07-31; LMT, 2018-08-01:
  • A 7-ship configuration, reduced to 5 ships using a 45 m CoM offset: at 2.5 rpm, 1 g on the lighter craft and 0.38 g on the heavier.
  • Richie-5 adds lunar g and Deimos g.
  • The "Richie Number" is the average number of ships in orbit per experimental run.
  • Concurrent tests: 1 BFS at 0 g, a pair at Mars g, 4 ITS + hub at Earth g LMT, 2018-07-18.
  • Terrestation. 782 m radius, 90 s period (Mars g), plus 1 g elevator gyms on booms LMT, 2018-07-06.
  • 20–25 ITS cargo flights for the marshalling-yard shell; telerobotic assembly; ISEP drag compensation; 12-step staging LMT, 2018-07-11.
  • A 1564 m EVLEO hemispherical shell of Mars FeNi plates LMT, 2023-01-07.
  • Dock on the fixed axis LMT, 2023-01-24.
  • Deimostation. Terrestation built in EVLEO; >90% of ~500 kt wet mass is ASCENT propellant (96% trawled O₂/N₂); 6.5 km/s to Deimos L1; tethered 14 km to Deimos LMT, 2023-01-14.
  • Other contributions. Lorentz-force spin-up LMT, 2023-04-02; electrodynamic drag cancellation LMT, 2018-07-06; autonomous tumble-docking research LMT, 2024-02-24.

Critiques raised

  • Paul451: wasteful; a single BFS end over end or two nose-to-nose would do (1 g at ~6 rpm) Paul451, 2018-07-16.
  • Paul451: it needs 4 BFS out of service for ≥2 years, effectively buying them Paul451, 2018-08-02.

Open questions

  • Is a multi-ship "Richie" formation practical given the propellant needed to hold 45 m CoM offsets?

Sources

Forum posts

  • LMT, 2018-07-06 (reply #884, 1 like): Terrestation. Post.
  • LMT, 2018-07-06 (reply #886, 1 like): ISEP. Post.
  • LMT, 2018-07-11 (reply #908): Terrestation staging. Post.
  • LMT, 2018-07-13 (reply #920): ITS 1 g station. Post.
  • LMT, 2018-07-16 (reply #941, 1 like): Hub details. Post.
  • LMT, 2018-07-16 (reply #947): Supplant Gateway. Post.
  • Paul451, 2018-07-16 (reply #950): Wasteful. Post.
  • LMT, 2018-07-18 (reply #979): Concurrent tests. Post.
  • LMT, 2018-07-31 (reply #1068, 1 like): Richie-class. Post.
  • LMT, 2018-07-31 (reply #1082): Configs. Post.
  • LMT, 2018-08-01 (reply #1102): Richie-5. Post. Attachments: RichieNumberTemplate.xlsx, Richie_Number__Simple_Example.png.
  • Paul451, 2018-08-02 (reply #1103): Buying ships. Post.
  • LMT, 2023-01-07 (reply #2803): Red Gold plates. Post. Attachments: Kalpana-24_Ba2-1920.jpg.
  • LMT, 2023-01-14 (reply #2894): Deimostation. Post. Attachments: Omaha_Trail_2021.png.
  • LMT, 2023-01-24 (reply #3057): Dock on fixed axis. Post. Attachments: QD.jpg.
  • LMT, 2023-04-02 (reply #3571, 1 like): Lorentz spin-up (1 like). Post. Attachments: 400 km geomagnetic field at 0 N 0 E.png.
  • LMT, 2024-02-24 (reply #4484): Tumble docking. Post.