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#40
by
Jim
on 03 Sep, 2006 00:06
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8-10 m
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#41
by
rumble
on 03 Sep, 2006 16:41
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Space Lizard - 1/9/2006 1:37 AM
NASA and anyone else won't go to Mars or elsewhere beyond the Moon without first testing long duration human flights in Earth orbit.
If it is not onboard a multipurpose space station, then it could be onboard a Mars vehicle staying in Earth orbit... and looking a lot like a space station with very few visitors.
Does anyone remember how tough it was to experiment anything in space when we had no Salyut, no Skylab, no Shuttle, no Spacelab, no Mir, no ISS?
Just take an empty Ares-V EDS and build a station along the lines of Skylab. Just bigger.
Would an Ares V core stage + SRBs be enough to orbit a mostly-empty EDS?
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#42
by
kraisee
on 03 Sep, 2006 19:44
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Absolutley.
The ESAS CaLV could loft roughly 106mT to LEO without the EDS. I suspect the RS-68 powered Ares-V could do broadly the same thing, gie or take a few mT.
Skylab massed 76mT, but they also lofted a bunch of supplies onboard at the start, so final launch mass was more like 100mT.
We could do it again if there were a requirement, and funding.
Ross.
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#43
by
mike robel
on 04 Sep, 2006 02:21
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We have already demonstrated long duration space flight of sufficient length to simulate a Mars mission on the ISS with the six months stays of crew. It can be done. The Russians demonstrated stays in excess of one year. We know what to do to counteract the weightless effects.
What must be done is build the spacecraft and test it for that period. Better yet, find a way to safely and consistantly produce G forces by rotationg the spacecraft.
Space Lizard - 1/9/2006 2:37 AM
NASA and anyone else won't go to Mars or elsewhere beyond the Moon without first testing long duration human flights in Earth orbit.
If it is not onboard a multipurpose space station, then it could be onboard a Mars vehicle staying in Earth orbit... and looking a lot like a space station with very few visitors.
Does anyone remember how tough it was to experiment anything in space when we had no Salyut, no Skylab, no Shuttle, no Spacelab, no Mir, no ISS?
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#44
by
CuddlyRocket
on 04 Sep, 2006 16:07
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mike robel - 4/9/2006 3:08 AM
We have already demonstrated long duration space flight of sufficient length to simulate a Mars mission on the ISS with the six months stays of crew. It can be done.
A Mars mission will take years, not six months. We have not demonstrated keeping a spacecraft functioning for that length of time without external supply - particularly of spare parts. I think people are going to want to see that accomplished before we launch humans to Mars.
I suppose you could test this on the Moon and/or in lunar orbit as part of some really extended lunar mission. Or they may demonstrate it on the ISS before its decommissioned.
The Russians demonstrated stays in excess of one year. We know what to do to counteract the weightless effects.
We know what to do to
slow down the deterioration caused by weightlessness. But astronauts now have only up to six-month stays on the ISS for a reason - and that's on the basis they return to 1g after the six months. Although lunar missions, again, should give us some pointers on the effects of lower, but non-zero gravity.
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#45
by
kraisee
on 05 Sep, 2006 02:09
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Mars gravity is 38% of Earths.
Is that going to be enough to keep Humans healthy? Would that offer sufficient g so that the 6-month sortie on the surface would repair 'damage' from the 9-month outbound trip, and offer a recuperation period prior to the 9-month return flight too?
I'd guess not, but with the space suits I'm thinking the active mass they'll be moving around on the surface will be fairly close to Earth-norm without the suit - and that's not a bad thing.
Ross.
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#46
by
Space Lizard
on 05 Sep, 2006 05:51
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mike robel - 4/9/2006 4:08 AM
We have already demonstrated long duration space flight of sufficient length to simulate a Mars mission on the ISS with the six months stays of crew. It can be done. The Russians demonstrated stays in excess of one year. We know what to do to counteract the weightless effects.
What must be done is build the spacecraft and test it for that period. Better yet, find a way to safely and consistantly produce G forces by rotationg the spacecraft.
Going to Mars and back is a two-year trip. This hasn't been demonstrated yet. Moreover, we need to demonstrate this hardware flight capability without visiting crews and resupply ships.
Artificial gravity is a tricky thing, as you need very long rotation radius to limit quite disturbing effects on people's vestibular system (you don't want to vomit each time you stand up and bump into walls each time you walk). Coriolis has some peculiar effects...
Large radius means you need to connect your habitat module to a counterweight. This makes a highly unmaneuverable vehicle with major structural issues...
There's still a lot to test in Earth orbit (not necessarily LEO) and a permanent flexible multipurpose manned platform will be required.
On a medical point of view, you don't do demonstrations with a dozen people, you need hundreds to understand what's going on.
How many astronauts have already achieved a fully medically-documented 9-month flight?
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#47
by
mike robel
on 06 Sep, 2006 03:32
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Going to Mars and back is a six month trip, a 1 year stay, and a six month trip back. The ISS is crewed for six months at a time now, so we know that Astronauts can last 6 months in a zero G environment. The Russians had cosmonauts in Mir for over a year in some cases.
The Russians proposed to NASA after Columbia to extend the stay to a year for the crews on the ISS. NASA demurred.
It seems to me that the thing to do - now - to begin gathering data for long duration space flights and prove out equipment, is
Put the ISS crew up for 6 months. After that, bring them down and have them spend 1 year in one of the Mars Society Stations or in Antarctica. Follow the completion of a year, send them back to the ISS for six months.
Eventually, for lunar missions do the same thing. The crew moves to the ISS for six months. At the end of that time, its off to the moon for a year, followed by six more months on the space station.
When we have a mars ship ready for testing, put that puppy either next to the ISS for six months, or send it on long looping orbits half a million miles or more from the earth for six months. Again, landing on the moon, then doing the same before returning to earth.
But my basic point is, flight time to Mars is about 6 months and the ISS crews have already shown that can be done. I certainly didn't say that we could do this tomorrow, although all Mars planning is always 20 - 30 years in the future. Its depressing.
Mike
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#48
by
mike robel
on 06 Sep, 2006 03:44
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OK,
Reviewing the thread to see what the consensus was for CEV use after 2016:
1. I forgot CEV Cargo flights in my straw man manifest from 2010 - 2016 - I guess there could be 2 per year for a 12 launches. Plus a maximum of 12 launches for crew rotations, assuming the Ares I and CEV are ready to fly in 2010. A not very likely possibility in my mind. However, one would think we would be able to sustain 4 Ares I launches per year.
By the way, in all the hoola, has anyone seen plans/concepts for the Cargo CEV's? Is there a published schedule for its development?
2. It seems to me COTS will come to nought and it will most likely not be cost effective.
3. After 2016, expect a two year hiatus of US Manned Space Flight as there will be no ISS to fly to and Ares V will not be ready for lunar rehearsals. What would program goals be for Orion flights in the interim?
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#49
by
Jim
on 06 Sep, 2006 03:55
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mike robel - 5/9/2006 11:31 PM
By the way, in all the hoola, has anyone seen plans/concepts for the Cargo CEV's? Is there a published schedule for its development?
There is no real difference between a cargo and a manned CEV. One has seats and the other doesn't. Actually, just most of the crew support systems have been removed.
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#50
by
CuddlyRocket
on 06 Sep, 2006 12:34
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mike robel - 6/9/2006 4:19 AM
Put the ISS crew up for 6 months. After that, bring them down and have them spend 1 year in one of the Mars Society Stations or in Antarctica. Follow the completion of a year, send them back to the ISS for six months.
That's not an adequate simulation, as the time spent in the Mars analogue station is on Earth at 1g.
For a Mars mission, the year will be at 1/3g. We don't know what the effect of spending time in a lower gravitational field is, but intuitively it should slow down any degeneration, and may even cause it to stop at some point. But at what point? The degeneration can't be allowed to go below a certain amount, as the astronauts may have to face a further six months at 0g, which would certainly lead to further degeneration, perhaps to dangerous levels.
A better simulation would be to send them to the Moon for a year. If they survice the process at 1/6g, they should be able to handle Mars. If not, we'd have to think of something else. (Realistically, we'd build up to these levels!)
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#51
by
bad_astra
on 06 Sep, 2006 16:14
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That makes sense to me. If the Lunar program has a bearing on lifescience for Mars, that's it
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#52
by
mike robel
on 06 Sep, 2006 21:09
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CuddlyRocket - 6/9/2006 8:21 AM
mike robel - 6/9/2006 4:19 AM
Put the ISS crew up for 6 months. After that, bring them down and have them spend 1 year in one of the Mars Society Stations or in Antarctica. Follow the completion of a year, send them back to the ISS for six months.
That's not an adequate simulation, as the time spent in the Mars analogue station is on Earth at 1g.
For a Mars mission, the year will be at 1/3g. We don't know what the effect of spending time in a lower gravitational field is, but intuitively it should slow down any degeneration, and may even cause it to stop at some point. But at what point? The degeneration can't be allowed to go below a certain amount, as the astronauts may have to face a further six months at 0g, which would certainly lead to further degeneration, perhaps to dangerous levels.
A better simulation would be to send them to the Moon for a year. If they survice the process at 1/6g, they should be able to handle Mars. If not, we'd have to think of something else. (Realistically, we'd build up to these levels!)
I agree that the best simulation would be go to the moon. However, since we are not going to the moon anytime soon, send them to the Antarctic, and once we have the stuff to keep them on the moon for a year, do that....
