Unfortunately nothing like gravity is so simple. supplies would have to be loaded from the axle and this really shouldn't be turning, but could with difficulty. moving anything around would cause balancing problems which must be compensated for, even walking from one end of a tube to the other would create dynamic loads which would then create other loads etc, until the station starts to tumble if not corrected. For a simple central-fugal machine to work it must be attached to something solid at its axis. To simulate Mars gravity on the moon is a definite possibility. This is not to say it cannot be done, but it is very complex. As a test you could build a spinning top on earth and try to keep it balanced with moving parts unbalancing it. Hmmm anyone want to try that?
I wouldn't propose a vehicle that is spinning at all stages of the flight.
There are lots of robust structures with which we are very familiar, and which are made from traditional materials - buildings, bridges and the rest - and all tend to be over-strong. Some of these even move. The true cost of AG in space is simply the launch cost - if we can build massive objects in space at moderate cost then we don't fall down the over-design hole - better is always the enemy of good enough.
My point is that you don't need to build a truly massive object in space in order to get a useful amount of gravity. Nor do you need special construction - just standard docking.
Quote from: Russel on 11/12/2018 04:41 amMy point is that you don't need to build a truly massive object in space in order to get a useful amount of gravity. Nor do you need special construction - just standard docking.These issues are already being discussed and debated on an existing thread - Realistic, near-term, rotating Space StationI suggest moving this discussion over there.
Quote from: Coastal Ron on 11/12/2018 06:14 amQuote from: Russel on 11/12/2018 04:41 amMy point is that you don't need to build a truly massive object in space in order to get a useful amount of gravity. Nor do you need special construction - just standard docking.These issues are already being discussed and debated on an existing thread - Realistic, near-term, rotating Space StationI suggest moving this discussion over there.Two examples of pragmatic artificial gravity that don't really fit in the realistic rotating space station:
- dealing with things sensibly and realistically in a way that is based on practical rather than theoretical considerations.
Bone loss in spinal cord injury is more severe than has ever been seen in space, so there is a substantial basis of experience here on earth. Bone density is maintained by physiological feedback mechanisms based not on gravity as an external force but rather on loading by muscles. This load can be reproduced by resistance exercise, which was one of the motivations behind various resistance exercise devices that have been flown. However some of the Russian long duration crewmen did not exercise at all and did have considerable bone loss. In one case one of the Russians resumed an intense regimen of running shortly after return and was reported to have suffered a stress fracture. The same thing has happened to paraplegics placed abruptly in full weight bearing in some early experimental rehab programs. Bone requires three to six months to gain significant strength when loading in increased, it responds m ore slowly than muscle. However bone loss is of significance only if it results in fracture. The risk of fracture after return is low even with long duration spaceflight without countermeasures, and moderate resistance exercise during spaceflight can limit it to levels that do not pose a significant risk. Artificial gravity may well be useful for control of floating objects or passenger comfort, but it is not essential for crew health.
That thread started with a post that is specifically about fixed space stations.
Its also mutated into building space stations into asteroid hollows.
I started this thread to talk about providing some level of artificial gravity to vehicles whose main purpose is transit between Earth space and Mars space.
Quote from: Russel on 11/12/2018 11:04 pmI started this thread to talk about providing some level of artificial gravity to vehicles whose main purpose is transit between Earth space and Mars space.Then I suggest the thread title be changed to "Realistic, Near-term, Rotating Spaceships".
That thread [...] mutated into building space stations into asteroid hollows.
For a simple central-fugal machine to work it must be attached to something solid at its axis.
Quote from: Russel on 11/11/2018 01:36 pmI wouldn't propose a vehicle that is spinning at all stages of the flight.Current experience suggests it takes a while (several days) for an astronaut to get used to 0 G. Regular exposure to that switch may improve it, or they may end up in a state of permanent disorientation...
However bone loss is of significance only if it results in fracture.
(1) I have always thought that the tiny radius AG shown in 2001 might in fact be reasonable for bone health for dedicated astronauts. Rather than actually having a convincing gravity environment, it could aim for say merely moon gravity, but it can also be used as a jogging track. Running in the right direction increases gravity.
Dizziness from turning your head is largely avoided by.. not turning your head.