Extended ISS missions

idiom · 2004-04-23 20:02:38

Just make yer tether longer.

Eventually you get down to the same corilis force experienced standing on the surface of Earth. Which would be twice as bad on the surface of Mars.

Also, if you rotated at say, 1.5 or 2g, isn't reasonable to expect that your heart and muscles would get stronger and that your bones would uber-calcifiy.

Imagine what two months on a 2g space station would do for a sports team...

GCNRevenger · 2004-04-23 21:37:43

But a continuous corolis force? For months on end, being unable to walk level unless you compensate for it... and then when its gone, you will just snap back to normal? Don't know about that...

The problem with making the cable longer is that the tension on the cable overall increases with length, so the cable must be stronger and heavier. Not to mention it increases the trouble of ship design.

idiom · 2004-04-24 02:33:38

I dunno. Maybe it the body would respond better than it does to wieghtlessness. Under those conditions you go nauseous until your brain switches your sense of balance of entirely (or just ignores it compeletly. It can take days for a returned astronauts brain to start listening to the inner ear again, so for that time period they are a bit of a danger to themselves.

If subjected to corolis perhaps you will feel nauseous when ever you turn you head sharply, but perhaps you brain will eventually filter those sensations as "garbage" because they don't corroborate the other senses.

Because you feel those sensations so little on earth it may take an extended period for your brain to trust those singals from your inner ear.

But could it really be worse than having no sense of balance at all?

GCNRevenger · 2004-04-24 07:36:25

Actually it could... if your brain is used to compensating for a force for that long, then it may not switch back to normal as readily as going from zero-G to Martian gravity.

bolbuyk · 2004-04-24 12:58:24

"I need power now, Scotty!!!"
"We can't go to warp for another 30 years, sir! I'm giv'n 'er all I've got!"
"Dammit Jim, our bones will decalcify...our muscles will shrink down to nuth'n!"
"Captain, the logical conclusion, under the present circumstances would be to spin the ship to create artificial gravity while using our chemical thrusters to guide us to our destination."
"Make it so."
"Who...let...Captain Pickard...on my.........ship?"

You're great!

bolbuyk · 2004-04-24 13:17:01

Doing the whole spinning spaceship thing is harder than it sounds and would add additional failure modes to the vehicle. Also, i'm not sure if putting astronauts under the Coriolis force for 4-6mo+ is a good idea.

I agree. At first glance, spinning seems the egg of Columbus, but working it out, problems arise. People moving from lower to upper parts of the ship undergo difference's in g. Course-corrections and navigation, even shielding are tough jobs with such a thing. Beside that, it should be stopped when preparing for decent.

A good part of the problems of zero-g arise at the first days of experiencing it. Vomiting, water-regulation of the body, that things. This can also have effect on the mental aspects of the astronauts.

Further, I think the zero-g problems are over-estimated. Muscle can be kept strong by excersising. The problem is more that cosmonauts refused this as much as was possible, so they came sometimes in troubles. Polyakov, a doc, who also co-designed the excersise-scheme of the cosmonauts, declared he did his two stay's without physical problems. About the decalcifying: As far as I know, their are reasons to assume this would stop after some months. One of the reasons to stay longer in space is to make data of that. Radiation has to be shielded, so there's no problem.

The only that remains are psychological aspects. A crew, together and also alone, no possibilitie to return immediately to a safe environment and no real-time communication with anybody outside the space-ship. Beside that no privacy, cramped space and, during a big part of the trip, even when they are some weeks on the martian surface, a very boring task.

This last aspect has to be researched with long-time submarine expeditions, IMO, because much of the aspects mach. Maybe a mission on the back of the Moon is an idea.

GCNRevenger: I didn't want to say staying long in space is practical or even physical not heavy. Smiling cosmonauts..... more and more becomes clear about what they went through. But all this said, long stay's are not a real problem. Much cosmonauts, and even NASA's Michael Foale do long stays for the second time.

Ian Flint · 2004-04-24 13:31:51

OK, most of this "spinning spaceship" discussion is just conjecture. Do we all at least agree that we should test one in orbit? Or, should we just assume that it is too hard or too unhealthy and do something else?

Ad Astra · 2004-04-24 13:57:47

If we did launch Mars Direct, we would have to fly precursor missions, such as a long-duration test (in earth orbit) of life support and artificial gravity of the Mars Direct habitat. From a fiscal point of view, it would be foolish to count on artificial gravity to work perfectly the first time you tried it; thus hurling $30 billion at Mars Direct and hence wasting it. Let's start small by testing artificial gravity on small animals with a bio-sattellite (I know I expose myself to attack by PETA by saying this.) The preliminary results will tell us which way to go. However, ISS is not the ideal place to be performing artificial gravity research.

Ian Flint · 2004-04-24 14:08:23

Ad Astra,

Umm...I hope you're referring to the Biosatellite that the Mars Society already has in the works. If not, you're about a year late and a mouse short.

I'm not sure how well the Biosatellite is progressing but I haven't heard any terrible news about it. So, they are probably still just trying to raise the money to launch it ($15 million).

Ad Astra · 2004-04-24 15:38:46

Indeed, I was talking about the Mars Society biosatellite, but I've heard conflicting reports about how it was progressing and whether it was a free-flyer or an ISS payload. I also spoke with someone who'd seen MIT's winning design in early 2002 and said he "wasn't impressed." I want to see somebody succeed with this project, but I won't be surprised if the Mars Society's effort fails.

Ian Flint · 2004-04-24 15:58:17

Well I hope it works. One thing I can't stand is how the Mars Society and other organizations don't report on what the heck is going on. I never know how much money has been raised or how much a project is progressing until they "unveil" the final product. It's like how the USSR hid it's launches until they were in orbit.

Give me some real progress reports, Zubrin (MIT, whoever)!!!

idiom · 2004-04-24 20:43:34

As I recall Mars Direct is designed to survive the tether braking and recover from the spin.

So if spinning fails so what, you still get to mars in six months.

You test it on mice and you get odd results... so you test it on monkeys...

15 years later your funding gets cut.

Can you imagine doing an apollo 10 to Mars? At Mars with all the equipment to land and live for two years... but no wait. We are going to ABORT just to check that we CAN.

Apollo style incremental stuff just won't work with Mars. It is way to long between runs. You just design it so that stuff like artifical gravity is really neat but not crucial, and so that the mission will survive it failing.

To expand on this... Maybe two years in deep space is really really bad. Lets assume that. Now the astronaut who discovers this may only discover this and wind up in a wheel chair for the remaining months of his life. period. Or he/she may get to walk on Mars then come back and die. Would you rather discover the bad news with no reward?

Mark Friedenbach · 2004-04-24 22:05:50

Can you imagine doing an apollo 10 to Mars? At Mars with all the equipment to land and live for two years... but no wait. We are going to ABORT just to check that we CAN.

The lunar module on apollo 10 wasn't finished. It was an early design that was too heavy to have returned from the lunar surface after landing.

idiom · 2004-04-24 22:51:43

Cost the same to launch as Apollo 11, and 8. Slightly more than eight, adding the cost of the lcm.

It was justifible during the 60's especially when 11 would fly only two months later.

It is a really expensive way of doing things though.

Ad Astra · 2004-04-25 13:13:49

Humans to Mars will require precursors to check out the hardware. I advocate a long-duration earth orbit mission to test the life support and artificial gravity, followed by a Mars flyby mission and finally a human landing. That's not to say these missions will be a waste of time and money. For instance, the flyby mission could use Zubrin's "Athena" flight profile, and the astronauts would control robots on Mars in real time. But I think we're inviting disaster if we send humans to Mars in untested hardware.

Mad Grad Student · 2004-04-25 14:41:31

Can you imagine doing an apollo 10 to Mars? At Mars with all the equipment to land and live for two years... but no wait. We are going to ABORT just to check that we CAN.

Huh? I don't think that's what Apollo 10 was about. Nor was it an old model too heavy to lift off the Moon, I believe that the mission plan from the start was to get within about five miles of the surface, test out how the LEM handled, and then get back up to the CSM without risking a touchdown. It was intended as a final shakedown run of the LEM before the real first attempt with Apollo 11. Naturally, this wouldn't work for a Mars mission, it would be a huge waste of time.

When you compare the difficulties of extended zero-g versus that of centrifugal gravity, the latter seems much more appealing. Compared to bone loss, heart weakening, muscle loss, and a host of other problems, the Coriolis effect is nothing. Really, artificial gravity is the best and safest bet we have right now.

Mark Friedenbach · 2004-04-25 14:42:55

Ad Astra and Mad Grad Student are correct. Engineering is an iterative process, and there's a lot that goes wrong. Even with today's computer simulations the only way to know if you won't have problems is to go out and test it. I would also add a moon flyby to the list as well, to test the trans-mars booster stage and high speed reentry/aerobraking.

idiom · 2004-04-26 00:59:47

I think we are highlighting a split in two schools of thought.

I can see going out and around the moon once and back, doing an "Earth direct" as a good way of testing Mars Direct hardware. However how many time will you test the Hardware?

Exploration is not an iterative process. You go as far as you can, as fast as you can. Currently we are doing that with rovers.

Research, is go a bit, come home, learn, go a bit further ... etc.

I am in the school of old style explorers I guess. Nasa is charged with doing research. If I had been in Apollo 10, I would have never made it home... I would probably have died on the surface.

PLIND · 2004-04-27 10:13:31

Tell you what we do, we strap a couple of kick ass rockets onto the ISS. We blast the whole station off to Mars (heh, the ISS is tested..it seems to be sound enough). Ahead of the ISS we have cargo ships of fuel etc. Of course, we'll need to send a CEV out ahead as well.
In addition to all this we hook up a rotating appendage to the ISS so that the astronauts can experience gravity along the way.
This sure would cut down on the budget issues AND put the ISS to real good use?

GCNRevenger · 2004-04-27 20:40:07

*shudders* Nooooo an ISS Mars ship? ...Give a guy nightmares...

The ISS is heavy. Too heavy. A Mars ship must be optimized for mass to keep the fuel demand down, and not for maximum scientific volume and electrical supplies. The "slap rockets on" is also a much, much harder proposition than it sounds considering the huge amount of fuel you would have to bring up to power them. The cost for modifying and fueling the thing for one trip would probably be in the hundreds of billions of dollars.

And sending ahead cargo that hasn't been designed yet in a vehicle that hasn't been designed yet for a mission that hasn't been designed yet... the crew transfer part isn't all that hard compared to the rest of the mission design.

dicktice · 2004-04-28 09:14:02

The ISS is not a space ship, any more than a railway station is a train. Empty fuel tanks boosted into orbit can be welded, etc. into dynamically balanced configurations suitable for rocket propulsion, by spacemen working out of the ISS, like trainmen assembling railcars, including the equivalent of a caboose for the habitat to live inside during the trip.

RobS · 2004-04-28 12:16:27

Whatever Mars mission hardware is selected, I wouldn't test it first by sending it to Mars. The surface stuff can be tested, partially, on the lunar surface. The rockets can be tested by sending stuff to the moon and back. The interplanetary habitat can be tested in Earth orbit, or it could be set up at L1 to serve as a waystation for a year or two (if L1 Gateway becomes an important travel node, it'll need a small space station; might as well use the interplanetary habitat for Mars). Once all the pieces are tested you send a crew to Mars. If they get in trouble on the way, you abort. If they get to Mars, they try out the landing equipment and set up the surface base.

ISS may prove to be a testbed for the technology, but it ain't going to Mars; it's eventually heading for the south Pacific, or it'll be reconditioned and become a Hilton.

-- RobS

idiom · 2004-04-28 15:28:41

Thats mostly stuff out of the clunking to Mars thread.

I don't see why you would test stuff on the moon, rather than Mars?

If something break you are still along way from Earth. Wouldn't you test it by re-entering and landing in Antartica or Australia?

Mark Friedenbach · 2004-04-28 18:18:28

don't see why you would test stuff on the moon, rather than Mars?
If something break you are still along way from Earth. Wouldn't you test it by re-entering and landing in Antartica or Australia?

gravity. mars structures would collapse under their own weight on earth

Euler · 2004-04-28 18:53:39

gravity. mars structures would collapse under their own weight on earth

No, because they would be small enough and over-engineered enough that they would do just fine with Earth's gravity.

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#26 2004-04-23 20:02:38

Re: Extended ISS missions

#27 2004-04-23 21:37:43

Re: Extended ISS missions

#28 2004-04-24 02:33:38

Re: Extended ISS missions

#29 2004-04-24 07:36:25

Re: Extended ISS missions

#30 2004-04-24 12:58:24

Re: Extended ISS missions

#31 2004-04-24 13:17:01

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#32 2004-04-24 13:31:51

Re: Extended ISS missions

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#38 2004-04-24 22:05:50

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#42 2004-04-25 14:42:55

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#47 2004-04-28 12:16:27

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