Why have I not seen any spin gravity testing in space? Or, more accurately, artificial gravity created through centrifugal/centripetal force. I haven't heard of any tests in standalone spacecraft or attached to the ISS, or any station.
Many far future sci fis have massive spinning cylinder ships and stations, multiple km long. But what about the precursors to this... or simply those more realistic in terms of cost and materials needed, such as:
- Cheapest: wire tethered capsules, such as Mars Direct ideas by R Zubrin:
- 2nd Cheapest?: spinning stiff trusses with capsules at each end:
- Quite costly: spinning rings:
I've seen centrifuge tests done on the earth surface (which overpower Earth g but cannot eliminate it), but have seen none attempted in space so far. Space allows testing of Lunar and Mars levels of g. The tethered capsule could even be a very small setup for lab rats. This seems hugely important for longer duration space travel, considering all of the bad effects of microgravity. A tether could be sent up and attached to spin existing small containers or entire ISS modules. Or SpaceX Dragon capsule with its spent booster as counterweight.
The math and mechanics are not a problem. Getting materials strong enough at reasonable launch weights isn't a problem. Controlling the spin through motors and/or thrusters should not be a problem. Tests could start at days long, then weeks, then months, and so on.
Even small, relatively cheap steps haven't been taken to space, such as 1-2 tiny capsules of lab rats spun on say 30-50m of light cable, near the ISS (not even attached to it, to avoid any disruptions such as vibration). Or anywhere in LEO, with plenty of sensors and cameras inside to monitor things.
It seems very feasible... so I ask, why have I not seen spin gravity testing done in space? (I looked, I swear :D)