View Full Version : Humans in Space

2004-Dec-07, 12:53 PM
Hi all,

I know a deal of research has been done on the effects of humans in space. How long could we survive in zero gravity? I know that a lack of gravity can affect our bones and obviously prolonged exposure to claustrophobic conditions would affect us mentally.

Can anyone furnish me with the information, and their thoughts please?

Many thanks,

Jake B)

2004-Dec-07, 02:51 PM
Remember we evolved and have our current being in space on spaceship earth, so the answer is, provided we continue to "outwit" chance, indefinitely. But not without simulated gravity or some fortutious planned mutation. As we continue to learn more about the long term exposure to low gravity and dangerous levels of radiation, we will discover/invent solutions such as using centrifuges to simulate gravity. It will be as easy, perhaps easier, for us to build (assemble in earth geosynchronous orbit) sufficiently large spaceships to adequately serve our needs as it is for the moundbuilding termites to build their mounds. This requires us to remain eternally vigilant about the types and number of "aardvarks" the universe has in store for us.

2004-Dec-07, 09:00 PM
Originally posted by Jakenorrish@Dec 7 2004, 12:53 PM
Hi all,

I know a deal of research has been done on the effects of humans in space. How long could we survive in zero gravity? I know that a lack of gravity can affect our bones and obviously prolonged exposure to claustrophobic conditions would affect us mentally.

Can anyone furnish me with the information, and their thoughts please?

Many thanks,

Jake* B)
Are you saying, it'll probably take longer for us to get to Mars than is generally assumed?? That along with many other problems will slow us down. Yup, I agree! :D

Check out this link:
http://www.smithsonianmag.si.edu/smithsoni.../phenomena.html (http://www.smithsonianmag.si.edu/smithsonian/issues04/jun04/phenomena.html)

2004-Dec-08, 03:30 PM
Hi Ulgah,

I think that humans travelling beyond the moon will not happen in my lifetime (I'm 32 by the way), but I've yet to hear what a scientist thinks about how long humans can survive in space. I think (as always!) that Gourdehead's answer is excellent. I think that space travel is hugely difficult, risky, and isn't even beyond the embryo stage into its infancy yet. I think that if (as some people do) we class the Earth and Moon as a double planet then we've yet to leave our own surroundings for another alien world yet, if you get my drift!!

Many thanks,


2004-Dec-08, 09:47 PM
Agreed. I believe it will be sometime after 2100 before we can land man on Mars, unless of course there are some unexpected breakthroughs in technology. If there are going to be breakthroughs, we had better start having some. The propulsion system is a real challenge, although probably the least difficult of the problems. Just point a giant rocket towards Mars and touch it off! LOL. There seems to be a little more to it than that. There are plenty of dreamers, we just need some doers. I am one of the former. :D

2004-Dec-09, 05:16 AM
It is seldom mentioned, but there is no need to tolerate longterm zero-g conditions. Two spacecraft can be joined by a moderately long cable and rotate around their common center. Rotating in a large circle will reduce Corriolis Effects, which are often overstated anyway. Apollo 13 illustrated that having a spare Spaceship can come in kind of handy!

Another serious obstacle is radiation. Just as the Earth is protected by a magnetic field, so can spacecraft emit a magnetic field that will deflect most charged particles from the sun; this doesn't solve the whole problem, but it is a good start.

Yet one more difficuly is carrying enough fuel to get off the Martian surface for the return trip. Personally, I think we should lower a cable from whichever Martian Moon's orbit most closely synchronizes with the rotation of the surface. The lander could land on the low-gravity moon and descend the cable down toward the surface. It would then fly from the end of the cable to the surface and land. It would return to orbit by first flying up to rendezvous with the cable and crawl back up the cable to the Moon using a small fraction of the fuel of a rocket-only approach. Such cables while currently infeisible with todays materials on Earth would work just fine for Mars. By the way, taking enough hydrogen there is easy, its the oxygen that is very heavey; however this can be easily manufactured on the Martian surface. With the discovery of water, perhaps even the hydrogen can be produced.

I think that people looking at a one-shot Mars mission have never moved beyond the Apollo Program paradigm. Going to Mars might not be so expensive if we have a reusable vehicle that simply ferries between Earth-orbit and Mars Orbit. Indeed, it is possible to set up a Space Station that actually orbits around the sun in a highly eliptical orbit that regularly takes it past Earth and Mars. Mars landers would remain in orbit around Mars, not carted back and forth to and from the Earth. Travel to Earth orbit would be in cheap Soyuz-type capsules powered entirely by reusable solid rockets. We would still be on the moon if we had used this approach.

Incidentally, some say that the Space Shuttles should be refitted as interplanetary explorers since the tiles are their achilles heel upon rentry into Earth's atmosphere, which will no longer be necessary.

Last but not least Helium 3 exists in abundance on Earth's Moon. We already have the technology to develop economical fusion using it if we were just committed to going and getting it. That would power flights throughout the Solar System in a matter of weeks not to mention solve Earth's energy and green house gas problems.

2004-Dec-09, 08:53 AM
Hi Scott

We also have the problem that if we travel to Mars, the chances are it'll either be a very short stopover or one of two years due to Mars' longer year, and us catching up and overtaking it. Like you I think that its a way off yet. I heard somewhere recently that the use of Phobos as a ready made space station could be considered along the lines of what you're suggesting.

Humans in space? I also think that we're more likely to make it to Mars when someone decides there's money to be made from it. I think that Nasa can gain what they need through the robotic probes they have been sending. No doubt these will get more sophisticated over the years, so private enterprise seems to be the way forward don't you think?

Jake B)

2004-Dec-09, 08:05 PM
Great ideas Scott, they actually sound somewhat workable. :)

Ola D.
2004-Dec-09, 10:26 PM
I can't estimate exactly when humans will be able to land on Mars, but i am expecting a long period of time though. Robotic missions are doing fine and highly contributed to our understanding of the martian surface and the rest of the planets. Until we have a fully-equipped technology in the future, i guess we should increase robotic missions.

2004-Dec-10, 12:40 AM
:P Now come on you must be jokeing. You sagest it will be 2100 before man lands on Mars. Concider this, from the time the Wright Bros., took to the air in that odd thing they called a airoplane, to the landing on the moon was about 63 years or so. How and why do you think it will take so long to reach Mars? We have the tecknoldgy now. Just the budget is requiered and zoom, of we go. All of those problems you speek of could be solved in a blink, with the funding required. Shielding from the cosmic and solar winds, no problem.. Centrafuge type craft designe, no problem. explain please?

Darth Maestro
2004-Dec-10, 01:32 AM
If we can put together a mission to confidently send Humans to land on Mars in less than 100 years from now... I think that is making pretty good time (at least I would be proud to have accomplished it in such a short timeframe). If i understand astromark correctly, I agree that it could be very possible for us to do it in less, yet I don't think that will happen.

2004-Dec-10, 02:15 AM
Tell them theres oil there and wotch them throw money at it then.

2004-Dec-10, 05:07 AM
technology is rapidly getting better. scientists are coming up with different ways to cure cancer and space radiation for austronuts. i think that by 2030-2050, we'll be able to land on mars.

2004-Dec-10, 06:33 AM
It seems to me that the problems of extended space mission are just that: problems. And prob-lems almost always have solutions.

Take weightlessness, for instance; there are at least four approaches: selection of people who are least sensitive to the effects of weightlessness, exercise, drugs and centrifugal force. People more or less routinely spend as long in weightlessness on the International Space Station as the journey to Mars would take. Combinations of these approaches may be more effective than any single one.

I think this problem has lots of potential solutions.

Humans, for millennia, have dealt with boredom and psychological problems due to isolation. The ISS is a good example, and there are submarines, arctic and Antarctic researchers, light house keepers of two centuries ago, well known sailing expeditions of the 15th, 16th, 17th, 18th, and even 19th centuries, castaways, and many other examples of well functioning groups.

Space travelers will have these big advantages over sailing expeditions that took place before the 20th century: continuous, high quality communication with home base; as much entertainment, news and education as anybody could want; and they not only will know where they’re going; they’ll be able to see it.

We can experiment with isolation issues as much as we want on Earth, but it hardly seems necessary since we already have so much experience.

Radiation is, I think, a manageable problem with drugs, predictions, and shelters. Other ap-proaches with magnetism or something else may also be possibilities.

Just because we don’t know all the answers today doesn’t mean we are dealing with insuperable problems, or even problems that are very difficult.


Dave Mitsky
2004-Dec-10, 06:58 AM
Barring some exotic advance in propulsion, a trip to Mars may be far more difficult than most people think:

http://www.smithsonianmag.si.edu/smithsoni.../phenomena.html (http://www.smithsonianmag.si.edu/smithsonian/issues04/jun04/phenomena.html)

Dave Mitsky

2004-Dec-10, 07:27 AM
With all the lack of knowledge of man's earlier travels and explorations of earth.........whether it be to the highest mountain or setting sail across the seas, in what we know today, the human desire of curiousity to set forth out into space, will exceed what ever pitfalls may lay before us. So it was in our past.......and so.....shall it be in our future. :)

2004-Dec-10, 09:21 AM
I think everyone has a fair point on this. Dave Mitsky's information is excellent. I think it will be a while before we overcome those problems. After all, the difference between getting a man to the moon or mars is a couple of hundred days. The environment on the spaceship would also have to be self sufficient in many ways. Not easy!!

2004-Dec-16, 06:13 AM
Re: Isolation

Send mathematicians-- they won't notice (or care) whether there's anyone else on board. S

2004-Dec-16, 09:08 AM
Sending mathematicians would have its plus points. If you needed to send any of the crew in to a deep sleep, then they'd be able to do that at the drop of a hat!


Jake B)