mikelepage: Dragon-based spin-gravity testbeds (2014–2023)

Design summary

• 2014: DragonLab tethered to its own F9 second stage as counterweight, with a cable reel in the nose; cut the cable and land. This was mikelepage's first post mikelepage, 2014-03-14.
• 2014: two DragonLabs joined by an ISS-style solar array stowed in the trunks; deployment pushes them apart.
• <$50M; 12+ generations of mice over 2 years.
• A ~32 m array gives 1 g at 5.3 rpm and 0.38 g at 3.3 rpm mikelepage, 2015-02-27; mikelepage, 2015-02-26.
• 2014: single-Dragon lattice. DragonLab + second stage + an ISS-type folding array in an extended trunk: 84 m, ~42 m radius. Moon g at 1.87 rpm, Mars g at 2.84, Earth g at 4.61 mikelepage, 2015-04-01.
• 2015: tourism-funded Dragon v2 + BEAM + second stage (21 m, 11.3 t). Groups at 0, 0.08, 0.16 and 0.24 g for 2-month stays; ~$50M launch, $25M per person mikelepage, 2016-01-18. Paul451: Dragon v2 life support lasts ~1 week, and celebrity tourists want 0 g.
• 2019: 2-Dragon configuration for a 1-month, 3-person test, exploring adaptation at 2–8 rpm and 7.5–12.5 m radii mikelepage, 2019-04-13; mikelepage, 2019-04-16.
• 2023: Polaris-type two-Dragon testbed. mikelepage, 2023-12-28; mikelepage, 2023-12-30
• An extensible pantograph ("lazy tongs") node with two IDSS ports, launched in the Dragon trunk; radius ~9–11 m in the cabins.
• The IDSS tensile limit of 17.7 kN (pressurized) allows only 14.4% g with a 12.5 t Dragon. The unpressurized vestibule limit of 100 kN allows up to ~80% g, enough for lunar and Mars g.
• Target: Artemis hardware tests (10 m / 3.85 rpm lunar g) and adaptation data at 3–6+ rpm.

Critiques raised

• The IDSS load limits constrain g; Twark_Main discusses pantograph designs Twark_Main, 2023-12-28.
• Dragon needs its trunk for power and thermal, has no toilet, and has only 9.3 m³ Coastal Ron, 2019-04-13.

Open questions

• Would SpaceX fly a crewed two-Dragon spin test, and could IDSS be qualified for tension loads?

Related pages

• Research and testbeds · Tethered bolas · Seals and joints

Sources

Forum posts

• mikelepage, 2014-03-14 (reply #151, 1 like): DragonLab + stage. Post.
• mikelepage, 2015-02-26 (reply #424, 2 likes): Lattice damps resonance. Post.
• mikelepage, 2015-02-27 (reply #433): Two-DragonLab lattice. Post.
• mikelepage, 2015-04-01 (reply #561, 1 like): Single-Dragon lattice. Post.
• mikelepage, 2016-01-18 (reply #832): Tourism testbed. Post.
• Coastal Ron, 2019-04-13 (reply #1543): Dragon limitations. Post.
• mikelepage, 2019-04-13 (reply #1545): 2-Dragon test. Post.
• mikelepage, 2019-04-16 (reply #1555, 3 likes): Adaptation range. Post.
• mikelepage, 2023-12-28 (reply #4376, 1 like): Pantograph testbed (1 like). Post. Attachments: IDSS mated load limits.png, Dragon SpinG testbed_small.mp4, D2testbed_preview.png.
• Twark_Main, 2023-12-28 (reply #4378): Pantograph; 100 kN. Post.
• mikelepage, 2023-12-30 (reply #4387, 1 like): Load limits (1 like). Post. Attachments: Bimetal_coil_reacts_to_lighter.gif, dual spiral.png, Dragon SpinG testbed_small.mp4.