Mars

[betafox]

Hi JonClarke.<br /><br />What do you think about this article:<br /><br />Can People Go to Mars?<br />http://science.nasa.gov/headlines/y2004/17feb_radiation.htm<br /><br />"But astronauts traveling to Mars will be "out there" for a year or more. "We can't yet estimate, reliably, what cosmic rays will do to us when we're exposed for so long," he says."<br /><br />It sounds strange with regard to rovers could already measured the radiation exactly as it is there on Mars...<br /><br />Read also this attentively:<br /><br />"The body of our planet, looming large, intercepts about one-third of GCRs before they reach the ISS. Another third is deflected by Earth's magnetic field. Space shuttle astronauts enjoy similar reductions."<br /><br />See that "Earth's magnetic field"?<br />This field mostly ptotects us on the Earth. <br />But on Mars it's very weak. Dangerous for people due to that fact.

 

[telfrow]

Just for a bit of background, here's some information on Jon. He's the right guy to ask. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[brandbll]

Yeah, well no wonder he's a little biased. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[JonClarke]

Space radiation hazards are to reduce that risk to manageable levels. Good spacecraft design (placing consumables and bulky equipment round the periphery of the craft) can lower exposures considerably, as does maximising the time on the surface of Mars and minimising transit times. Additional shielding can be supplied to key areas to provide a storm shelter. Good space weather forcasting will also mean that crews won't be caught out on the surface of the Moon or Mars during a solar flare or CME. Not much can be done about cosmic rays however, they are too energentic for any pratical shielding except living underground. They will just have to be put up with on exploration missions.<br /><br />My understanding is that, using current technologies, a the crew of 1000 day Mars mission will still be within current exposure limits for astronauts. This means that both human expeditions and permanant stations are possible. <br /><br /> Long turn settlements with people living their lives on the surface are problematic because of cosmic rays, unless people are prepared to spend 96% of the lives underground, accept a much higher cancer morbidity, or there is a breakthough in treatment of radiation damage.<br /><br />But I will happily settle for expeditions and stations!<br /><br />Jon<br /> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[JonClarke]

Or maybe I just know enough about the subject to be dangerous.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[telfrow]

<img src="/images/icons/laugh.gif" /> <br /><br /><img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[betafox]

JonClarke: "Not much can be done about cosmic rays however,"<br /><br />That means you admit this. I suppose.<br /><br />From the article:<br />"If the extra risk is only a few percent… we're OK. We could build a spaceship using aluminum and head for Mars." (Aluminum is a favorite material for spaceship construction, because it's lightweight, strong, and familiar to engineers from long decades of use in the aerospace industry.)<br /><br />"But if it's 19%… our 40something astronaut would face a 20% + 19% = 39% chance of developing life-ending cancer after he returns to Earth. That's not acceptable." ...<br /><br />The error bars are large, says Cucinotta, for good reason.<br />...<br />"<br /><br />Dangerous, too expensive, too complicated. Impossible?<br />Like to the Moon?

 

[brandbll]

Can you explain how NASA determined that a Mars Mission at 1,000 days would be safe? Your talking like its just some protocol trip when it's about 3 times as long as any stay in space ever. And that's with the Earth's magnetic field's protection. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[telfrow]

<font color="yellow">Dangerous, too expensive, too complicated. Impossible? Like to the Moon?</font><br /><br />For the second time, please, don't try to insert that topic in this, or other, threads in ATA. <br /><br />If you want to discuss the moon landing "hoax," please open another thread. There are any number of posters here who would be happy to discuss it with you. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[betafox]

brandbll: "And that's with the Earth's magnetic field's protection."<br /><br />That's what I'm talking about. I think he know a few about such things. hmmm... underground on Mars... Very strange theory!

 

[betafox]

telfrow: "For the second time, please, don't try to insert that topic in this, or other, threads in ATA."<br /><br />It is a part of my sentence. A part of my thought. I cannot just cut it off. Understand?

 

[telfrow]

Please see my previous post. <div class="Discussion_UserSignature"> <strong><font color="#3366ff">Made weak by time and fate, but strong in will to strive, to seek, to find and not to yeild.</font> - <font color="#3366ff"><em>Tennyson</em></font></strong> </div>

 

[brandbll]

betafox what are you talking about? <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[betafox]

JonClarke: "Long turn settlements with people living their lives on the surface are problematic because of cosmic rays, unless people are prepared to spend 96% of the lives underground, accept a much higher cancer morbidity, or there is a breakthough in treatment of radiation damage. "<br /><br />So to live on the surface is problematic because of cosmic rays. <br />Underground???<br />Today's technology can't manage such expensive effort on Mars I think.

 

[TheShadow]

Stevehw33 says: <i> No one has yet designed a stable, self contained habitat, which can exist long term without substantial inputs of materials and energy sources. </i><br /><br />Only because it has never been necessary. As long as it has been easier to re-supply astronauts, the investment in designing a self-sufficient CELSS has never been necessary. I believe we could build such a system with current technologies if we really wanted to. It is mostly an engineering problem, integrating several current technologies into a single system.<br /><br />However, a 100% self-sufficient system in not necessary, even on a mission to Mars. Robotic cargo vessels can be used to carry supplies to Mars in advance of the astronauts. Without life-support systems and requirements for short transit times, robotic cargo ships can carry relatively large amounts of supplies economically, and land them at the proposed landing site or sites. People often forget that on of NASA’s mandates is finding such landing and/or colonizing sites.<br /><br />That being said, although possible, it would not be practical to grow food either on the spacecraft or (initially) on Mars. Most of the food would have to be taken along, or sent ahead. A great deal of weight can be saved by using freeze-dried foods. If you have ever eaten freeze-dried foods created for backpacking campers, you will know that it is really excellent. Almost any meal you can imagine can be preserved that way. Astronauts could literally have a different dinner every day for their entire mission.<br /><br />Stevehw33 says: <i> People outside of gravitational fields lose muscle mass and bone calcium. If they do not return to normal gees within several months, the NASA limit is 4 mos., there is NO full return to normal earth gravity functioning. </i><br /><br />Perhaps you can provide credible proof of that claim. You also might want to inform returned long term astronauts that they aren’t supposed to be doing so well, that it is <div class="Discussion_UserSignature"> <p> </p><p> </p><p> </p><p> </p><p><font size="1" color="#808080">Who knows what evil lurks in the hearts of men, the Shadow knows. </font></p> </div>

 

[JonClarke]

Cosmic ray risk: You will just have to put up with it. Cosmic ray risk on Mars is about the same as cosmic ray risk in LEO. It's an acceptable risk for LEO, it will be acceptable on Mars, at least for the time frames we are talking about.<br /><br />Cosmic rays risks have not precluded missions to LEO or to the Moon. Thus they do not preclude missions to Mars. <br /><br />Jon <br /><br /><i>edited for spelling</i> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[JonClarke]

What's strange about the possibility of permanant settlements on Mars being underground? It has been discussed in the literature for decades. Not only does it eliminate cosmic radiation hazards, it also minmises temperature fluctuations. It makes a lot of sense for the Moon also.<br /><br />As for cost, it is too expensive for today's priorities. However 20 - 30 years down the track priorities may be different and technology will certainly have advanced in that time.<br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[nexium]

Underground living quarters MAY be too costly on the moon or Mars. We have equipment that can locate natural caves below the surface of both Moon and Mars So the probability is at least fair that caves will be suitable at low cost.<br />Living 10 centimeters underground 96% of the time (for 50 years) may be correct, but my guess is 50% is ok 10 meters below ground of either moon or Mars. A small percentage of the galactic cosmic rays penetrate more than 10 meters of regloth etc. Neil

 

[JonClarke]

The caves might be difficult to find, may not be in the right location or of the right size, and could need considerable engineering work (cleariong of rubble, reinforcing, shaping of entrances) before they are suitable for habitation. Cutr and fill techniques may be simpler, although that will depend on how easy it is to excavate lunar and martian regolith. Burial of surface structures is also a possibility, simply mounding regolith over the top.<br /><br />Jon<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[brandbll]

You have to remember landing sites. I doubt there is a cave anywhere near the places NASA is going to be considering for safe landing sites. <div class="Discussion_UserSignature"> <p><font size="3">You wanna talk some jive? I'll talk some jive. I'll talk some jive like you've never heard!</font></p> </div>

 

[danyopizzle]

Ive either made this up in my head or its allready made up, but i believe that mars has had life a long time ago just like us, mars core is the same core that the earth has but the core stopped spinng so now mars is a desalated planet, the earths core is slowing down as well. the earth will look like mars when the earths core stops spinning

 

[qso1]

There has been much speculation about Mars supporting life eons ago. I suspect Mars never supported more than microbiological organisms mainly because Mars may once have had an atmosphere, one probably not as thick as Earths. And over time, Mars atmosphere slipped away because Mars gravity is not enough to hold an atmosphere for long.<br /><br />Extremophiles may well be present on Mars to this day but we won't know till we get samples of such organisms.<br /><br />One person who is well known for his theories of ancient life like us or in this case, more advanced is Richard Hoagland. But as his case rests upon the alleged image of a face on Mars, known here at SDC as FOM. He's probably more interested in writing and selling his works rather than actually using scientific methods to develop a workable theory because he has developed some pretty outlandish theories on other solar system bodies.<br /><br />This would not really be possible until we can do field work such as investigating the FOM locally. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[mollygirlmn]

I keep receiving emails saying that next month, Mars will be the closest it's been to Earth in eons and that it will be like having a 2nd moon. This can't be right, can it?<br /><br />Let me know . . . . <br /><br />

 

[mollygirlmn]

Ok, disregard this posting. I read down the list and found same question. I have my answer now. Thanks!

 

[qso1]

Definetely not right, Mars never gets close enough to Earth to appear as the moon does if thats whats meant by having a second moon. And the last closest approach was in 2003 around August IIRC. That was the closest approach in 60,000 years. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>