Starship-based stations

Using whole Starships (or their predecessors ITS and BFR/BFS) as habitats, counterweights or structure. This was one of the thread's longest debates, from 2018 to 2025.

Key results

Configurations (Paul451's catalogue) Paul451, 2019-04-03

Configuration Rotation g-levels quoted
Single ship "hotdog" about long axis Mars g at 8 rpm, lunar at 6. Long-term unstable.
Single ship "tumbling pigeon" end-over-end, CoM mid-ship 1 g at nose at ~6 rpm; Mars ~3; lunar ~2
Two nose-to-nose "baton" end-over-end Similar rpm, with g in the right direction (the nose crane hardpoint carries it)
Two tail-to-tail end-over-end "Upside-down" g: 1 g at nose at 4 rpm, Mars at 2.5
Two side-by-side (dorsal) + nose cable + tunnel flat spin 1 g at 8 rpm; Mars under 4; lunar ~3. Stable unless engines are ≥80–90% of mass Paul451, 2019-04-06
  • Earlier BFS versions: two ships tail-to-tail (48 m each, 40 m to deck) give 0.4 g below 3 rpm; a single BFS end-over-end gives 0.4 g at ~4 rpm Paul451, 2018-07-17.
  • Tail-to-tail pairs on the way to Mars at ~2.5 rpm WH2OPaddler, 2019-03-27; WH2OPaddler, 2019-04-30.
  • Four Starships (a tail-to-tail pair plus two more nose-docked) at ~2 rpm give 0.38 g in the outer pair and 0.17 g in the inner pair: Mars and Moon g together punder, 2022-12-25.
  • Three Starships at 120° manage the moments of inertia better than two Twark_Main, 2023-01-08.
  • Nose-to-nose tethered. An 85 m tether at 2 rpm → Mars g, using the lifting hardpoints. Only two launches of capital, and the ships land at the end edzieba, 2019-04-09.
  • Single Starship with methane ballast in the lower tank to vary the radius, testing rpm against g rakaydos, 2018-08-04.

Structural loads

  • The steel tanks run at about 3.5 atm and see >3 g at launch, so they are strong in tension. Only the latches or nose-tether structure need reinforcing mikelepage, 2019-04-08; mikelepage, 2019-05-03.
  • Tail-to-tail clamps are designed for ~40 MN launch loads versus ~1.1 MN tension at 1 g (r = 48 m, 4.3 rpm) mikelepage, 2018-08-03.
  • Paul451: the tank walls already hang the engine section at 1 g; internal pressure is 600 kPa; the nose supports crane lifts; the thrust structure takes multi-g compression. "Starship is overengineered for use as a spin station" Paul451, 2022-12-26; Paul451, 2022-12-31.

Objections (mostly Coastal Ron)

Counterpoints

  • Contract services, not purchases, as with HLS or a GEOsat bus. SpaceX retains ownership, which avoids export issues. SpaceX bid a Starship-derived station for NASA's Commercial LEO Destinations program Paul451, 2022-12-31.
  • Shared development: comms, GNC, power, ECLSS and HLS lunar-g systems come "for free". Modules are replaced by new-generation ships Paul451, 2022-12-31.
  • Starship as a reflyable, reconfigurable temporary station: a micro-g lab one month, spin tourism the next, a 6-month lunar-g animal lab after that. This proves the market before dedicated stations Paul451, 2019-04-06.
  • HLS must include systems that work at 0.17 g and 0.38 g anyway. A Mars-transit Starship is a station punder, 2023-01-03.
  • mikelepage: Starship-derived designs are "pre-first-generation" mikelepage, 2022-12-29.

Starship as launcher and tool, not structure

Open questions

  • Will SpaceX ever lease whole ships for months? Its apparent interest in LEO-destination work (CCSC-2, 2023) suggests it might LMT, 2023-06-16.
  • Which configuration gives the best research value per launch?

Sources

Forum posts

  • Paul451, 2018-07-17 (reply #965): BFS pair tail-to-tail 0.4 g <3 rpm. Post.
  • mikelepage, 2018-08-03 (reply #1110): Clamps 40 MN vs 1.1 MN tension. Post.
  • Coastal Ron, 2018-08-03 (reply #1119, 1 like): BFS compression not tension; tanks boil off. Post.
  • rakaydos, 2018-08-04 (reply #1127): Single ship with ballast to vary radius. Post.
  • WH2OPaddler, 2019-03-27 (reply #1411): Two Starships tail-to-tail for Mars cruise. Post.
  • Paul451, 2019-04-03 (reply #1467, 3 likes): Single/pair Starship spin configurations (3 likes). Post. Attachments: BFS side-docked.png.
  • Paul451, 2019-04-06 (reply #1477, 1 like): Parallel config stability analysis. Post.
  • Paul451, 2019-04-06 (reply #1485): Starship as reconfigurable temporary station. Post.
  • mikelepage, 2019-04-08 (reply #1503, 1 like): Tanks 3.5 atm, >3 g launch → strong in tension. Post. Attachments: FHaccel.png.
  • edzieba, 2019-04-09 (reply #1511, 1 like): Nose-to-nose tether 85 m, 2 rpm, Mars g. Post.
  • WH2OPaddler, 2019-04-30 (reply #1565, 3 likes): Tail-to-tail render approaching Mars (3 likes). Post. Attachments: IMG_0001 (4).jpg.
  • mikelepage, 2019-05-03 (reply #1583, 1 like): Only latches/nose tether need reinforcement. Post.
  • clongton, 2019-05-03 (reply #1585): Propellant moves to nose; engines lose prime. Post.
  • Coastal Ron, 2022-10-04 (reply #1842): Starship 8 m × 17.24 m. Post.
  • Coastal Ron, 2022-10-10 (reply #1968): Starship User Guide payload. Post.
  • mikelepage, 2022-10-14 (reply #2077): Starship ~$10M per flight. Post.
  • lamontagne, 2022-12-12 (reply #2634): Extended 22 m payload option. Post. Attachments: fairing.PNG.
  • punder, 2022-12-25 (reply #2715, 1 like): Four Starships: Mars + Moon g at 2 rpm. Post.
  • Paul451, 2022-12-26 (reply #2718): Starship loads: overbuilt for spin. Post.
  • mikelepage, 2022-12-29 (reply #2720, 1 like): Starship-derived = pre-first-generation. Post.
  • Coastal Ron, 2022-12-30 (reply #2725): Three objections to Starship-derived stations. Post.
  • Paul451, 2022-12-31 (reply #2732, 1 like): Contract services; SpaceX bid Starship station (1 like). Post.
  • Paul451, 2022-12-31 (reply #2733): Shared development benefits. Post.
  • Paul451, 2022-12-31 (reply #2738): Only compressive parts matter; reversed loads fine. Post.
  • Coastal Ron, 2022-12-31 (reply #2744): HLS cost $2.89B → purpose-built modules instead. Post.
  • Coastal Ron, 2022-12-31 (reply #2745): Dead mass ratio; no iteration path. Post.
  • punder, 2023-01-03 (reply #2758, 1 like): HLS systems at partial g; lease and return ships (1 like). Post.
  • Coastal Ron, 2023-01-07 (reply #2799): Slosh and shear on nose docking. Post.
  • Twark_Main, 2023-01-08 (reply #2808): Three Starships at 120°. Post.
  • mikelepage, 2023-03-31 (reply #3566, 1 like): Starship OMS as spin-up anchor (1 like). Post.
  • Coastal Ron, 2023-04-09 (reply #3589): Ship stretch; want 8 × 10 m. Post.
  • mikelepage, 2023-04-11 (reply #3594): Payload doors may limit width. Post.
  • Twark_Main, 2023-04-15 (reply #3609): Door geometry analysis. Post.
  • Coastal Ron, 2023-04-27 (reply #3649, 2 likes): Earth-built modules via Starship = sweet spot (2 likes). Post.
  • InterestedEngineer, 2023-06-02 (reply #3767): Custom expendable Starship modules. Post.
  • Coastal Ron, 2023-06-02 (reply #3768): Custom Ships likely >$100M. Post.
  • Coastal Ron, 2023-06-09 (reply #3806): Near-term: Starship as cargo hauler, not component. Post.
  • DanClemmensen, 2023-06-11 (reply #3836): Launch 9 × 40 m tubes and weld. Post.
  • LMT, 2023-06-16 (reply #3877, 1 like): SpaceX Starship as LEO destination element (CCSC-2) (1 like). Post. Attachments: SpaceX LEO destination - Berger 6.15.23.png.
  • lamontagne, 2023-10-02 (reply #4107): Starship $25/kg LEO, $250/kg L5. Post.
  • mikelepage, 2024-07-23 (reply #4656): Rim-docked Starships provide propulsion. Post.

External references

  • SpaceX, Starship Users Guide v1 (2020).
  • NASA CCSC-2 announcement (June 2023): Blue Origin, Northrop Grumman, Sierra Space, SpaceX, Special Aerospace Services, ThinkOrbital, Vast.