Astronaut Scott Kelly on the devastating effects of a year in space

[Flyaway]

Certainly points up how difficult colonising somewhere like Mars will be.

NASA astronaut Scott Kelly spent a year in space. His recollections of this unprecedented test of human endurance, and the physical toll it took, raise questions about the likelihood of future travel to Mars.

http://www.theage.com.au/good-weekend/astronaut-scott-kelly-on-the-devastating-effects-of-a-year-in-space-20170922-gyn9iw.html

 

[DWG]

Interesting, the blood pooling in the legs happens in a couple of earthbound disabilities, SCIs and POTS, so there's potential for synergistic research.

 

[Triton]

The article raises the concern that the human body may not be capable of enduring long-duration spaceflight due to physiology. All of the plans for manned spaceflight to Mars presume that human beings can tolerate a voyage in conditions similar to those found in the International Space Station. Will manned spacecraft also have to simulate gravity to prevent health problems for the crew? Are there health problems associated with visits to celestial bodies with lower gravity than Earth?

 

[kitnut617]

One thing I always bring up in conversations with friends on space travel is they'll have to go in something a damn sight bigger than a ISS size spaceship. Being cooped up in something that small for anything longer than what they do will turn people nuts -------

 

[Flyaway]

The article raises the concern that the human body may not be capable of enduring long-duration spaceflight due to physiology. All of the plans for manned spaceflight to Mars presume that human beings can tolerate a voyage in conditions similar to those found in the International Space Station. Will manned spacecraft also have to simulate gravity to prevent health problems for the crew? Are there health problems associated with visits to celestial bodies with lower gravity than Earth?

I’ve always thought we will not be totally able to colonise space until we are able to sufficiently ‘upgrade’ ourselves be it through technology or altering our own genetics, or we are going to have to invent things like artificially gravity and I know which option is the more likely.

 

[DWG]

'Artificial gravity' is pretty easy to fake, you just need to spin the habitat. We're building a little too small to do it at the moment, but there are multiple options that become practical at not a lot larger than the ISS.

 

[Orionblamblam]

'Artificial gravity' is pretty easy to fake, you just need to spin the habitat. We're building a little too small to do it at the moment, but there are multiple options that become practical at not a lot larger than the ISS.

There is a straightforward solution for the likes of the SpaceX interplanetary transporter: launch two of them into low Earth orbit. Fuel them up, stock them up with cargo and passengers, then launch them side-by-side (well, a mile or three apart) simultaneously towards Mars. Once they've shut down their engines and begin the months-long cruise, rendezvous, dock them nose to nose, then *slowly* start to spin them up. Connect them via a good stout tether, let the tether unreel for a half kilometer or so. You can build up whatever G-level you like (lunar or Mars would probably be good, no need to go full-G). Either cut the tether and fling the two craft in different directions at the end of the flight, or reel them back in, slow the tumble and stow the tether for re-use.

 

[DWG]

Twin-body spin is mechanically the simplest of the options, others are internal spinning 'hamster cages' and rotating hull sections. The twin-body cable-linked option also has a major advantage in that it can have a significantly larger radius of spin than the others, which means a lower rotation rate for the same rotational acceleration, which also has some phsyiological advantages.

 

[merriman]

Twin-body spin is mechanically the simplest of the options, others are internal spinning 'hamster cages' and rotating hull sections. The twin-body cable-linked option also has a major advantage in that it can have a significantly larger radius of spin than the others, which means a lower rotation rate for the same rotational acceleration, which also has some phsyiological advantages.

.... and. If the cable is from nose-to-nose the spin gravity is along the same line as earth gravity -- the floor is still the floor no mater if on earth or out in space. That simplifies accommodations.

David

 

[Dynoman]

NASA's Nautilus X concept with a rotating living-space structure is estimated to cost 3.7 billion and a build time of 64 months is an interesting concept which utilizes large inflatable structures for work, storage, and living space. They have also considered an ISS demo version of 80-150 million and a construction period of 39 months.

https://www.youtube.com/watch?v=hObbL4DCesI

 

[Hanse]

Either cut the tether and fling the two craft in different directions

I don't know that you'd want to *cut* the cable while under rotation. I'm reminded of a snapping tow-strap but on a much larger scale.

 

[DWG]

There are rotating tether concepts for orbital boost that effectively do just that on a much larger scale. There is energy in that rotational system, better to find a way to use it than to throw away more energy cancelling it out.

 

[Orionblamblam]

Either cut the tether and fling the two craft in different directions

I don't know that you'd want to *cut* the cable while under rotation. I'm reminded of a snapping tow-strap but on a much larger scale.

Done right, you'd cut both ends simultaneously. The tether would *already* be as stretched out as it is going to get, so as the counterweights zip away from it, the tethers oscillations would not be able to reach them.