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Old 2009-05-16, 09:21   #1
ixfd64
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Default manned Mars mission - your thoughts?

Over the decades, there have been numerous manned missions to Mars have been proposed, but so far none of them have been carried out due to technological limits and budget constraints. However, some of the recent proposals, such as those related to Bush's Vision for Space Exploration, seem much more promising. Despite our technological advances, a manned mission to Mars still poses daunting challenges.

The Moon is about 238,855 miles away from Earth, but the distance to Mars is almost 35 million miles at the minimum. A round trip to Mars will take many months (in fact, many such proposed missions are over two years long) and require a large amount of supplies. I've seen estimates that well over 100 tons of cargo (fuel, food, air and water) will be needed to support six astronauts over 500 days. However, I've also heard about proposals that involve generating fuel from the Martian atmosphere, which can definitely decrease the cost. In-situ resource utilization (ISRU) works in theory, but has anyone actually put it to the test? If astronauts were to use an ISRU system on Mars, it had better work perfectly the first time. I've also heard proposals that involve converting solid wastes back into food and water via closed loop processing, but I don't think many people will find the idea of food derived from bodily wastes very appetizing. Some have also proposed growing food in space, but this technology is far from perfect. Until we can solve these problems, we will just have to ferry all these supplies (as well as the scientific equipment) to Mars and back.

There is also the problem of getting back to Earth. Since Mars' gravity is over twice that of the Moon, a spacecraft will require more powerful propulsion to leave the planet. That means we can't just rely on simple boosters, like the ones on the Apollo lunar modules. Astronauts would also have to set up a launch pad and make sure it works properly.

On such a long mission, the chances of something going wrong are much higher than on a mission to the Moon. If a vital system were to fail, the astronauts could be in big trouble. For this reason, many proposals call for double or triple redundancy systems to serve as backup. For example, if a mission involves using ISRU to create fuel for the return trip, it may not be a bad idea to bring extra fuel, especially on the first mission. That way, if the ISRU system does not work as planned, the astronauts can still get back home. (On the other hand, if it does work, they can always leave the manufactured fuel, or the fuel they brought, for the next crew.) The same goes for the water, oxygen and food. What if an astronaut forgets to turn the water off after taking a bath? What if a collision with space debris causes an oxygen leak?

There are psychological concerns as well. A spacecraft can be very crowded, and in some cases, the living conditions are not much different from being in prison. In fact, some prisoners have it better. For example, some correctional facilities allow visits from relatives, and prisoners may be lucky enough to taste a home-cooked meal. Unfortunately, these things are pretty hard to get when you're 70 million miles from Earth. In comparison, prisoners often get to exercise in the courtyard, whereas astronauts are stuck in a rocket 24/7 - at least until they reach Mars. Since prisons often have large populations, the prisoners often have many chances to socialize. Unfortunately, astronauts are stuck with three to five fellow crew members - unless they don't mind the long delay between communications with Earth due to the large distance. These living conditions will surely drive many people insane. The lack of, a-hem, people of the opposite gender, may also pose a problem.

There is also a social issue. While most Americans support a manned mission to Mars, such a mission would be extremely costly. There will certainly be people who will be opposed to their tax dollars being used for "frivolous" purposes. Indeed, if the money for a manned Mars mission were used towards charity, it could definitely put a dent in world hunger.

So, what are your thoughts on a manned Mars mission? Do you think it will take place before 2037, as Michael Griffin hinted? Will it even be possible?

Personally, I think it will work this time. I am quite excited, even though I have to wait 28 years for it. I think it will be an even "bigger" event than World War II.
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Old 2009-05-16, 09:42   #2
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Waste of time and money. Better to create robots for exploring. Robots are much cheaper, don't have the body waste problems, don't complain if left folded up in a small capsule, etc. Plus you can send hundreds of robots for the same cost as one human. And not just Mars, look at Voyager I and II, that is money well spent.

The downside is, of course, robots are stupid. But with time scales like 28 years we can send dozens of robots to Mars for less cost and learn little bits of information slowly without risking lives and large amounts of money on one manned mission.

Send robots there (anywhere, not just Mars) first to create fuels and oxygen and whatever else. Once that is all in place only then start thinking about sending humans when the robots can not do any more for us.

Last fiddled with by retina on 2009-05-16 at 09:43
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Old 2009-05-16, 12:12   #3
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Originally Posted by retina View Post
Send robots there (anywhere, not just Mars) first to create fuels and oxygen and whatever else. Once that is all in place only then start thinking about sending humans when the robots can not do any more for us.
Just don't make them too smart so they want to come back for revenge...

Last fiddled with by Jeff Gilchrist on 2009-05-16 at 12:13
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Old 2009-05-17, 16:08   #4
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Quote:
Originally Posted by ixfd64 View Post
In-situ resource utilization (ISRU) works in theory, but has anyone actually put it to the test? If astronauts were to use an ISRU system on Mars, it had better work perfectly the first time.
It would first be tested on the Moon (using modules for Moon-available resources) and in unmanned Mars missions, I'm sure.

Quote:
There is also the problem of getting back to Earth. Since Mars' gravity is over twice that of the Moon, a spacecraft will require more powerful propulsion to leave the planet. That means we can't just rely on simple boosters, like the ones on the Apollo lunar modules.
Why not (with over twice the thrust)?

Quote:
Astronauts would also have to set up a launch pad
Why can't the lander be designed for launching as well?

Quote:
On such a long mission, the chances of something going wrong are much higher than on a mission to the Moon.
Personally, I think the toughest problem is going to be radiation shielding. Earth's magnetic field shields the ISS from solar wind.

Quote:
There are psychological concerns as well.
That's something that Mir/ISS have been able to help investigate -- perhaps the best argument for manned space stations.

Quote:
A spacecraft can be very crowded, and in some cases, the living conditions are not much different from being in prison. < snip > These living conditions will surely drive many people insane.
The space travelers will be volunteers and there will be extensive psychological tests before acceptance. Not so in prisons.
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Old 2009-05-18, 12:59   #5
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Quote:
Originally Posted by ixfd64 View Post
...The lack of, a-hem, people of the opposite gender, may also pose a problem.
Maybe some male astronouts (a-hem, blush) could be persuaded to join the women on their epic journey? Or are men considered too inept for such an undertaking?
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Old 2009-05-18, 15:26   #6
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Quote:
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... and there will be extensive psychological tests before acceptance.
So we just end up sending autistic people.
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Old 2009-05-18, 15:53   #7
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Maybe some male astronouts (a-hem, blush) could be persuaded to join the women on their epic journey? Or are men considered too inept for such an undertaking?
A woman needs a man like a fish needs a bicycle
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Old 2009-05-18, 16:00   #8
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I think the Apollo missions were a good idea, but came too soon in the sense that the technology for building a base on the moon -- particularly the computer and power technology -- was lacking. Future exploration should be more about putting down bases and infrastructure, which, though mind-blowing in terms of initial cost, will make long-term navigation around the solar system much cheaper.

If in-situ resources can't do everything, then we're in a situation of having bases which are unmanned much of the time, given the tremendous cost of launching food, water, and everything else to the moon or Mars. But this is still better than launching a manned vehicle to one point on Mars, messing around for a few months, and then returning the people while leaving tons of material which will never be used.

Any future manned missions should focus on laying down infrastructure on the moon, Mars, or a satellite of Jupiter (Europa?).

Robotic probes are getting so good and reliable, and are so cheap compared to even a single shuttle launch, that the benefits of manned exploration relative to the costs are still low. This will change as propulsion and shielding technology improves: sure, it takes a lot of energy to move from one body to another, but it's mostly a matter of containing and releasing that energy intelligently.

Also, because robotic probes are so sophisticated, I doubt we'll learn much about Mars from the first few manned Mars missions. Instead, we'll learn about human psychology and how do mitigate the effects of long-term stress and isolation. I like a vacation as much as anyone, but having to wait at least 20 minutes to communicate with friends and family from another planet, where you're living under unrelenting stress in an enclosed structure, makes for a hell of a challenge.
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Old 2009-05-18, 16:30   #9
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Quote:
Originally Posted by FactorEyes View Post
Instead, we'll learn about human psychology and how do mitigate the effects of long-term stress and isolation. I like a vacation as much as anyone, but having to wait at least 20 minutes to communicate with friends and family from another planet, where you're living under unrelenting stress in an enclosed structure, makes for a hell of a challenge.
That is so much a recent development!

Back in the good old days, yet still within living memory, it took weeks to communicate with friends and family on a different continent. Only 20 minutes communication would have been astounding for almost everyone around 50 years ago.

As for lengthy round trips confined in a small vessel with limited company and bad food, consider how large chunks of the earth were explored --- again, not so long ago.

The youth of today don't know how cushy a life they lead. When I were a lad...


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Old 2009-05-18, 20:00   #10
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Back in the good old days, yet still within living memory, it took weeks to communicate with friends and family on a different continent.
I have been idly pondering examples of true isolation, without instantaneous human communication outside a tiny group. The best historical examples seem to be epic sailing voyages and, even better, polar exploration.

Some of the sailing -- say, Magellan or Cook -- was isolating or at times terrifying, but I believe they were never away from land of some sort for more than a few weeks at a stretch, even if land was a vacant island. Probably the present-day solo circumnavigators, even with radio equipment, are under more strain, because they are alone in small vessels.

Shackleton's 1909 expedition -- the one less famous today -- included a trip to the polar plateau by a party of four, who travelled alone for several hundred miles, without any communication and no margin for error. You missed a depot? Kiss life goodbye!

The Belgica expedition of the 1890s included Roald Amundsen, and made for some strange psychological strains during a winter spent locked in the ice. And Bird (?) spent a winter alone in Antarctica, at one point experiencing hallucinations.

It could be that nothing about Mars will be any tougher on the human brain than this. There are few hints as to anyone having a breakdown on the space station.

What new difficulties does Mars throw at humans?
  • No possibility of rescue within a year or two
  • No possibility of stepping outside to get some air
  • Everyone, and everything, you have ever cared about will be on a tiny bright object in the evening or morning sky

But at least there won't be scurvy, and starvation is not likely.

Last fiddled with by FactorEyes on 2009-05-18 at 20:01
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Old 2009-07-19, 04:09   #11
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Originally Posted by ixfd64 View Post
There is also the problem of getting back to Earth. Since Mars' gravity is over twice that of the Moon, a spacecraft will require more powerful propulsion to leave the planet. That means we can't just rely on simple boosters, like the ones on the Apollo lunar modules. Astronauts would also have to set up a launch pad and make sure it works properly.
It would be logical to plan a one-way trip, leaving the astronauts to die at the end of the mission. This would require a craft or crafts capable of delivering into Mars orbit the crew, sufficient supplies for the duration of the mission, and a lander capable of taking the crew + supplies to the surface. A return trip, by contrast, would require a craft or crafts capable of delivering into Mars orbit a craft capable of returning the crew to earth, additional supplies for the return journey, and a lander capable of landing the crew + supplises, and returning the crew to orbit.

The latter option would undoubtedly require many additional millions of full-time worker-years to engineer, with consequent loss of many more lives.
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