manned Mission to Mars discussion

[Bad Bishop]

I have watched several episodes of Mars Rising on the Science Channel. The series makes it clear that a voyage to Mars would be too dangerous to the crew, given the current state of technology. Maybe the spacecraft could provide a kind of artificial gravity (by rotating part or all of the ship). Still, there would no way to provide protection for the crew against cosmic rays. Imagine all your astronauts returning home from Mars with the bones of 80-year olds plus cancer throughout their bodies.

I would favor further R & D, but not committing to manned voyage to Mars for at least another 50 years. Why not just concentrate on exploring the moon for the next few decades?

Incidentally, on the Fox News Channel today, Bill O'Reilly asked Rep. Barney Frank where the money for nationalized health care would come from. Frank suggested that he'd take money away from a manned Mars project (among other things like defense), though he does approve of unmanned space exploration. NASA, watch your wallet.

[chardman]

BB-

Not sure how to address this. NASA obviously knows whether or not they have the means to deal with cosmic rays, and it's not been presented as a major stumbling block in any of their manned Mars proposals thus far, so I assume they have a workable solution in mind. I've certainly heard a number of workable solutions presented in the past, so don't think this is a problem. Still, I imagine it gets mentioned in a lot of science/educational shows, as shows of this sort often exaggerate the danger, as it makes for more exciting and memorable television. The Discovery Networks (of which The Science Channel is a part) are especially guilty of indulging in blatant sensationalism.

And the gravity issue is pretty much moot as well, as you've presented the obvious solution (a centrifuge of some sort) in your post.

The only stumbling block you've alluded to, which I believe has any real merit, is the political aspect of funding the mission.

[FemurBone]

Bad Bishop wrote:

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I have watched several episodes of Mars Rising on the Science Channel. The series makes it clear that a voyage to Mars would be too dangerous to the crew, given the current state of technology. Maybe the spacecraft could provide a kind of artificial gravity (by rotating part or all of the ship). Still, there would no way to provide protection for the crew against cosmic rays. Imagine all your astronauts returning home from Mars with the bones of 80-year olds plus cancer throughout their bodies.

Christopher Columbus sailing across the Atlantic Ocean in a wooden sailing ship with no radio, electricity or GPS was far more dangerous than a manned mission to Mars would be.

As far as the effects of weightlessness on bones is concerned, Russian Cosmonaut Valeri Polyakov spent 14 months aboard the Mir space station and his bones are fine.

and I also believe this cosmic ray buisness is over exagerated.

[noknowes]

chardman wrote:

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So, what's your source for this? Cause thus far, the largest NASA estimate I've seen has been about $450bn, and that's for one of their most ambitious manned mission proposals. They have others mission plans which are far more modest and economical. So, again, link?

Again, I'll need some reliable evidence of the totally outrageous figure you've mentioned, but as far as propulsion systems go: The technology we have is proper. Sure, it would be great if someone invented the mythical "space drive", but it hardly makes sense to delay in anticipation of a technology that might not emerge for centuries, if ever. That's the pipe dream.

Thankfully, waiting for a quantum leap in propulsion isn't at all necessary, as the consensus among experts in the aerospace industry is that standard chemical rockets that we are building now are perfectly adequate for the job.

So, please explain why should we listen to you when the experts almost universally disagree with you?

The figure for 2 trillion is correct.Have you heard of cost over runs?

Just about EVERY single HIGH PRESTIGE project has always had cost over runs.Just look at the International Space Station cost over runs.

The cost over run were phenomenal.

By the time this project gets of the ground,which i seriously doubt,the cost will be conservatively at least 2 trillion.

Lower costs are being quoted to get funding then of course once it gets under way the price will skyrocket.

No politician in his right mind is going to vote for a $2 trillion Mars mission.

IF YOU DON'T BELIEVE ME LOOK AT ALL THE PREVIOUS HIGH PRESTIGE PROJECTS.

Find out the estimated quoted figures at the start and actual cost at the end.

[SilentP]

noknowes wrote:

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The figure for 2 trillion is correct.Have you heard of cost over runs?

Yes, people know of cost over runs, however, just a blanket statement of 2 trillion being the end correct cost isn't viable, since nothing has been attempted at all. Would you like to show how you got to a figure of 2 trillion? Calculations with sources, please.

[jefferiestubes8]

Since this is the Science and Technology forum I'd like to address the trip from Earth to Mars. I believe it will be the 7 month journey but to the astronauts it will feel like they are just on the Intl.Space Station and not moving.
Will any EVAs be required every 60 days for inspections of the hull? Will a robotic arm with an HD camera be able to do it?
Is a centrifuge like in "Mission to Mars" (2000), "Red Planet" (2000) and "2010" (1986) going to really happen?

Re: Budgetary/Funding discussion
I swear I am going to create a thread in the Misc. subforum for that!. Please can you get back to the Science and Technology of the topic? As science fiction fans we all are speculating on the science anyway...

[SilentP]

jefferiestubes8 wrote:

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Since this is the Science and Technology forum I'd like to address the trip from Earth to Mars. I believe it will be the 7 month journey but to the astronauts it will feel like they are just on the Intl.Space Station and not moving.
Will any EVAs be required every 60 days for inspections of the hull? Will a robotic arm with an HD camera be able to do it?
Is a centrifuge like in "Mission to Mars" (2000), "Red Planet" (2000) and "2010" (1986) going to really happen?

Re: Budgetary/Funding discussion
I swear I am going to create a thread in the Misc. subforum for that!. Please can you get back to the Science and Technology of the topic? As science fiction fans we all are speculating on the science anyway...

Agreed, I'll stick with the actual topic.

I'd definitely say that EVA walks will be necessary, even in addition to a robotic repair arm. I mean, what would you do if the arm itself was what needed repairing/inspection? How easy it would be to repair may be another matter, or the hull in fact.

I'm not sure about a centrifuge being used for such a journey, how big would a vessel have to be for the circular nature of the floor not to be unobtrusive (if that concern means anything)? Such curvature in a small vessel might make the actual design of the workspaces inflight more complicated to make the simulated gravity worth anything.

Unless say you were to have certain sections with a centrifuge, say the gynasium, which I'm pretty sure would be required in a vessel for such a long journey, if the astronauts are to keep up their muscular strength.

Such modularisation might require a lander module, for a dedicated landing and take off, while other modules are responsible for intra-planetary flight control and the like.

[Daedalus12]

chardman wrote:

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BB-

Not sure how to address this. NASA obviously knows whether or not they have the means to deal with cosmic rays, and it's not been presented as a major stumbling block in any of their manned Mars proposals thus far, so I assume they have a workable solution in mind.

http://www.theregister.co.uk/2007/11/29/nasa_mars/

Well yes NASA has mentioned as it a major stumbling block in their manned proposals. The other one being cost of course.

I can tell you for sure that NASA scientists now think it's one of the major engineering challenges. It's a stumbling block in the sense that NASA won't do a manned mission to Mars until the magnitude of the radiation risk is well-known. Right now there is a large uncertainty. If risk turns out to be great (which some of them already think so) then some sort shielding must be included in the final plan. No it can't be lead because of mass issue. There are plenty of technical documents (both public and private) from NASA dealing with this topic. No I don't get my information from the Discovery channel or any space news media.

[SilentP]

Daedalus12 wrote:

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I can tell you for sure that NASA scientists now think it's one of the major engineering challenges. It's a stumbling block in the sense that NASA won't do a manned mission to Mars until the magnitude of the radiation risk is well-known.

I may be incorrect, and they've actually done it, but wouldn't you have thought with all the probes being sent towards Mars and in that general direction, that they would have fitted the in-transit vehicle with some form of radiation sensors to get a feel for the amount of radiation present in the open vacuum?

[Daedalus12]

SilentP wrote:

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I may be incorrect, and they've actually done it, but wouldn't you have thought with all the probes being sent towards Mars and in that general direction, that they would have fitted the in-transit vehicle with some form of radiation sensors to get a feel for the amount of radiation present in the open vacuum?

The amount of radiation is well-known. The total amount of exposure expected for a 2.5 years manned mission is equivalent of about few hundred years here on Earth. It's the effect on human body that is not well-known i.e. how much is the increase in the risk of dying from cancer. The estimates vary widely and there is no good way to test it. I admit NASA is very much conservative on this front. Actually they are very conservative on most fronts. But the risk is real and not some figment of imagination.

[SilentP]

Daedalus12 wrote:

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The amount of radiation is well-known. The total amount of exposure expected for a 2.5 years manned mission is equivalent of about few hundred years here on Earth. It's the effect on human body that is not well-known i.e. how much is the increase in the risk of dying from cancer. The estimates vary widely and there is no good way to test it. In the end some sort of radiation protection will have to devised before any manned mission to account for the potential severe solar storm which we already know is lethal within the magnitude of hours. I admit NASA is very much conservative on this front. Actually they are very conservative on most fronts. But the risk is real and not some figment of imagination.

Gotcha.

As for a type of protection, you'd be correct in that lead would be right out, due to mass.

Would it perhaps be possible for a ship to carry a device to replicate the effect of a planet's magnetosphere? I'll admit right off that I don't know enough geology to know how the Earth create's it's mangentosphere or if it's possible to replicate on a small scale, but something like that could reduce the amount of radiation absorbed by the craft and crew...

[Daedalus12]

SilentP wrote:

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Gotcha.

As for a type of protection, you'd be correct in that lead would be right out, due to mass.

Would it perhaps be possible for a ship to carry a device to replicate the effect of a planet's magnetosphere? I'll admit right off that I don't know enough geology to know how the Earth create's it's mangentosphere or if it's possible to replicate on a small scale, but something like that could reduce the amount of radiation absorbed by the craft and crew...

For the more instantly lethal radiation events like a massive dose of fast traveling protons from a solar ejection a modest amount of aluminum would be enough. Although I don't know precisely all the details.

The higher priority placed by NASA admin. is on the type of radiation (coined HZE) that would pose more long-term health risks. Most of the risk uncertainty and technical challenge comes from these radiations. There has not been any technical demonstration but theoretically it could be as you said magnetic based.

You can read this paper if you have AIAA membership or if you are at an university with AIAA subscription. It's an old one but it's good.

HZE particle shielding using confined magnetic fields

[chardman]

noknowes wrote:

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The figure for 2 trillion is correct.Have you heard of cost over runs?

So no actual links, just some figures you pulled out of your ass, eh?

But assuming you are right this time, you've just proven that there's plenty of money for a NASA Manned Mars Mission. Because NASA has put forth less ambitious manned mission scenarios with estimated budgets of only about $30bn. Utilizing the noknowes magic cost overrun ratio of roughly 4.44 to 1, that gives us a grand total of less than $150bn to fund one of these alternate mission plans.

I also notice you've totally ignored addressing the propulsion issue.

Not at all surprised.

[Daedalus12]

Actually here I'll just provide the paper if the Mods would indulge this slight violation of AIAA rules on distribution.

Paper

[SilentP]

Hopefully they will, the first page view they allow on the website has me interested, but I couldn't follow it further.

I'll have to look at it when I get home however, since my work net won't allow access to 'Personal Network Storage' sites