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Mars mission a sham

  1. Apr 29, 2006 #1

    wolram

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    Space weather.

    http://www.marstoday.com/news/viewpr.html?pid=17536

    Dr Foullon points to particular concerns about the radiation dangers of Solar Proton Events (SPEs) particularly those that follow Coronal Mass Ejections (CMEs - massive clouds of material ejected from the Sun that produce dangerous, high energy, charged particles). One of the largest such events ever recorded arrived at Earth in August 1972 right between NASA's Apollo 16 and 17 manned missions. Simulations of the radiation levels an astronaut inside a spacecraft would have experienced during this event found that the astronaut would have absorbed lethal doses of radiation within just 10 hours. It was simply good luck that this happened between the missions.

    Propulsion

    http://www.lascruces.com/~mrpbar/staifpaper.html

    Several studies (Paine 1986, Cohen 1989, and Stafford 1991) [sDH1]over the past decade have identified the difficulties of sending manned missions beyond the moon. Most prominent of these are the radiation levels between .01 to .02 Sv per week from galactic cosmic rays and the substantial decalcification of bone that occurs in a zero gravity environment. In addition, psychological problems associated with living in confined quarters for long periods of time have been indicated by incidents on board the Russian space station, MIR. The effects of all of these threats can be reduced substantially by reducing the total mission time to eight to ten months. To accomplish this and maintain a reasonable mass fraction for the Initial Mass in Low Earth Orbit (IMLEO) of the ship, a high thrust system with a specific impulse greater than 2000 seconds will be required. The gas-core fission rocket is the most likely candidate to achieve this performance in the near future.

    The Bush plan.

    Retiring the three remaining space shuttles in 2010, after the space station is completed. NASA does not yet know how astronauts would get to the space station in the four years between retiring the shuttles and starting to use the new spaceship.


    http://www.thespacereview.com/article/579/1

    Putting humans on Mars will require a quantum leap in both science and industry. The technical challenges are so daunting, in fact, that many of the leading scientists responsible for getting us from here to there doubt that it is possible. “What worries me most,” says Gentry Lee, a veteran of the Apollo missions and the lead systems engineer at NASA’s Jet Propulsion Laboratory, “is that I don’t think that we're smart enough to pull it off right now.”
     
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  3. Apr 29, 2006 #2

    wolram

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  4. Apr 29, 2006 #3

    Astronuc

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    Space missions are planned so as to avoid "Solar Active" periods, precisely to avoid SPE's. I just attended a conference where this was the topic of a paper.

    Not really. The matters are well known, and have been a major consideration since the beginning of manned-flight in space. I know several people who are currently working on shielding issues.

    It seems like some individuals in NASA do not know what others are doing. Our bureaucratic government at work. :rolleyes:
     
  5. Apr 29, 2006 #4

    wolram

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    Astro, could you tell me about the mission plan ? will it be a long or short
    option, are they using N power, if it is the long option have they solved
    bone probs, what are some dates for stage completion.
     
  6. Apr 30, 2006 #5
    For the bone problem there has been a device proposed that generates gravity through cytripical motion while exersizing the astronauts on a bike-like thing.
    -scott
     
  7. Apr 30, 2006 #6
    I work specifically on this problem. Like astronuc said, missions are planned around SPE events. Actually SPE events are not of concern for a Mars mission. They are relatively short duration and a radiation hardened chamber within the greater spacecraft would be enough given advanced warning. The greater risk is the constant background radiation of Galactic Cosmic Rays.

    There is also a lot of work being done on shielding materials.

    You can see one of the design tools that has come out of the CSMB at:

    http://sirest.larc.nasa.gov/index.html
     
  8. May 1, 2006 #7

    Integral

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    Just think about how much real science could be done with the money wasted on a manned Mars mission. We could probably put enough robots on the surface of Mars to explore the entire surface.

    What will we get from the manned mission? At best a video of low gravity golf and a suitcase full of rocks.
     
  9. May 1, 2006 #8

    Ivan Seeking

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    As you know Integral, I completely agree. The cold war is over, so let's look at what makes the most sense for good science. Also, let commercial ventures take regular folks to space.
     
  10. May 1, 2006 #9

    wolram

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    http://www.planetary.org/programs/projects/space_advocacy/budget_statement.html

    The Bush Administration's proposed 5-year budget for NASA, just submitted to Congress, is an attack on science. The proposed budget directs three billion dollars (over five years) away from robotic exploration of the solar system to continue to operate the shuttle. Last year the Administrator said, "not one thin dime" would be so directed. Now we learn it is 30 billion dimes.

    Science missions are being cut out of the program or delayed. Among them:

    * Rejection of a request from Congress for a new start for a mission to explore the ice-covered world of Jupiter's moon, Europa. Such a mission is the highest-priority objective outlined in the NRC/Planetary Science Community's most recent Decadal Survey: The under-surface ocean on Europa could be a habitat for life;

    * Delay of the Space Interferometry Mission -- a key effort contributing to the understanding of the universe and the search for other planetary systems;

    * Cancellation of the long-sought Terrestrial Planet Finder, a mission also supported in the original Vision for Space Exploration, to discover Earth-like planets and possible abodes for life around other stars;
     
  11. May 2, 2006 #10

    Chronos

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    Another vote for Integral. It is insane to even consider spending the kind of money it would take to launch a manned mission to mars. The very idea nauseates me.
     
  12. May 2, 2006 #11

    Astronuc

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  13. May 2, 2006 #12

    Astronuc

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    I'll dig around for my notes, which are somewhat old, but I plan to explore more recent mission analysis. Basically, the transit time depends on the mass of the craft, the available power, and the specific impulse of the propulsion system.

    As Norman mentioned, there is an active program to look at shielding of spacecraft. GCR is a concern as well as SPE's. For long missions, the spallation reactions in the structural materials (particularly Al) of the spacecraft hull are a concern. Surrounding the astronauts with water and propellant (liquified H2, NH3, or CH4, or solid LiH) would be one way of improving the shielding. The best shielding for ions is light elements like H and Li, while the best shielding for gamma and X-ray radiation is the heavier elements, which also increase mass, which increases the propulsive energy requirements.

    I don't believe a manned mission to Mars should be prohibitively expensive, if planned correctly, and it should not necessarily preclude other science programs. Some of the technology is relevant to terrestrial energy applications. In that sense, there are basic materials science and nuclear energy applications that apply to future terrestrial energy systems, as well as any manned or unmanned spaceflight missions.
     
  14. May 2, 2006 #13
    Why not? A quatum leap in secience and industry would be a good thing. It would be hard but that's what secience and engineering is for.
     
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