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"Dr. Tsou devised a way to capture comet particles and bring them back to Earth for NASA’s Stardust mission and has been suggesting a similar method for a space

by jmpe 13y ago

"Dr. Tsou devised a way to capture comet particles and bring them back to Earth for NASA’s Stardust mission and has been suggesting a similar method for a spacecraft that would fly through Enceladus’ plumes and then return to Earth for scientists to examine. The challenges are to make sure that the interesting particles would not break apart, to take precautions that any alien life would not infect Earth, and to fit it into the $500 million budget of one of NASA’s lower-cost planetary missions." Why bring it back to earth? Wouldn't it be safer & less expensive to return it to ISS instead, (or is that what's implied) ? Didn't know the carbon & nitrogen part of the story, read the article thinking only 1 thing: "when are you going to mention Europa".

maaku 13y ago
> Why bring it back to earth? Wouldn't it be safer & less expensive to return it to ISS instead, (or is that what's implied) ? No, that would involve a very complicated and expensive breaking maneuver to slow down the spacecraft, not to mention getting in exactly the right orbit to rendezvous with the ISS. It's much, much easier to just the payload sturdy enough to survive atmospheric entry and a crash landing.
- mkingston 13y ago
  Expensive breaking is precisely what they're trying to avoid! (Sorry, normally I wouldn't nitpick spelling when the meaning is clear, it was just a funny error!)
  - maaku 13y ago
    Hah! I had to reread twice to spot the mistake. That's too awesome; I'm going to leave it as-is.
- rkuykendall-com 13y ago
  What about crashing it into the moon? Higher cost, but much less chance of earth contamination. We could then check it out with cheap robots.
  - didgeoridoo 13y ago
    An object coming in from a rendezvous with Saturn would be traveling at a ludicrous speed. You would probably vaporize on lunar impact. The Earth's atmosphere can help slow it down to a reasonable velocity--otherwise you have to carry a lot more fuel to burn in a slow-down maneuver.
    - hrjet 13y ago
      Similar to how a swing-by is used to accelerate a space-vehicle, I wonder if a swing-by could be used to decelerate as well.
      - vilhelm_s 13y ago
        According to Wikipedia, the MESSENGER mission to Mercury used a complicated series of fly-bys of Earth, Venus and Mercury to slow down.
      - Tuna-Fish 13y ago
        It can. The boost is proportional to the cos(final exit trajectory in relation to the planet, velocity of planet) -- so if the probe leaves the planet opposite to the direction it goes around the sun, it slows down. (that is, the probe as whole can still orbit the sun in the same direction as the planet, it just needs to do it slower.
    - BrandonMarc 13y ago
      Ludicrous speed?! I bet they have hyperjets on that thing! (ducks)
- fit2rule 13y ago
  Send two missions, one with the capture device, the other with a functioning remote-controlled robot laboratory. Leave them close to the region, set them up to explore for 50 years or so. I know, I know, budgets. It'll 'never' happen. But what if we just send a nano-factory with its own assembly/disassembly abilities? Feasible, 5 - 10 years on from now? Well anyway, the point is: why bring it back, really? Just send more machines to do better jobs in space.
TrainedMonkey 13y ago
I doubt in orbit rendezvous with ISS would be safer and cheaper. It might be safer from planetary contamination standpoint, but complexity of such maneuver would handily offset that. On top of that there is a host of other issues due to the cramped space on ISS. For example: not enough space for proper isolation of sample, not enough equipment to properly study sample, and the fact that limited manpower would be available for examination. Regarding planetary contamination, with the amount of meteorites hitting ocean I do not think we have anything to worry about.
- jmpe 13y ago
  That makes sense. But regarding your last sentence: I'm not very fond of that risk analysis. Potentially introducing an alien aquatic micro-organism (that's what we hope to bring back, remember) into earth's system... No competition, paradise compared to its hostile home. No meteorite has ever been shown to carry life, but into this case we intend to deliberately introduce it, either controlled or uncontrolled. NASA can bill me for the extra cost for taking it to ISS instead of earth's surface.
  - bausson 13y ago
    No competition? A life form which evolved in a (relatively) low-energy environment (low temperature, low light level, lower pressure) is more in hell than in a paradise. Earth organism evolved to make the best of available resources on Earth, be it energy or materials; the organism would be teared apart in no-time. That is, unless it is a highly intelligent and evolved life form with big environment alteration capacities, but then it might already be a problem, just one we aren't aware of.
- civilian 13y ago
  Eh, I've played KSP, an orbital rendezvous in LEO on your return isn't that hard. If you have enough precision and fuel leftover to start a safe decent, you have enough precision and fuel to dock with the ISS. I'm surprised that we aren't equally worried about contaminating Enceladus with terran microbes.
elnate 13y ago
In regards to the contamination, I don't think that would be a real risk. Earth life has spent billions of years both adapting and adapting to the environment to make it the best growing medium and even then it exists in exclusive bands. For example, put a polar bear in the desert or a fresh water fish in salt water. It is more likely that we would have to take extreme care not to kill any lifeforms we brought back than to worry about them killing us.
- jmpe 13y ago
  You're seriously underestimating this issue. - rabbits/cane toads in Australia [0][1] - Japanese knotweed [2] - Tumbleweed (yep, not as native as Hollywood suggests) [3] - Algae [4] ... and the list goes on and on, here's a top-100: http://en.wikipedia.org/wiki/List_of_the_world%27s_100_worst_invasive_species http://en.wikipedia.org/wiki/List_of_the_world%27s_100_worst... [0] http://www.youtube.com/watch?v=pgPhn4tYxJQ http://www.youtube.com/watch?v=pgPhn4tYxJQ [1] http://en.wikipedia.org/wiki/Cane_toads_in_Australia http://en.wikipedia.org/wiki/Cane_toads_in_Australia [2] http://www.environment-agency.gov.uk/homeandleisure/wildlife/130079.aspx http://www.environment-agency.gov.uk/homeandleisure/wildlife... [3] http://en.wikipedia.org/wiki/Kali_tragus http://en.wikipedia.org/wiki/Kali_tragus [4] http://plants.ifas.ufl.edu/node/89 http://plants.ifas.ufl.edu/node/89
- TeMPOraL 13y ago
  I don't think anyone is worried about space bears or space fish; but bacteria / viruses / other basic replicator forms have much bigger resistance to harsh environments.

by jmpe 13y ago

maaku 13y ago

> Why bring it back to earth? Wouldn't it be safer & less expensive to return it to ISS instead, (or is that what's implied) ? No, that would involve a very complicated and expensive breaking maneuver to slow down the spacecraft, not to mention getting in exactly the right orbit to rendezvous with the ISS. It's much, much easier to just the payload sturdy enough to survive atmospheric entry and a crash landing.

mkingston 13y ago
Expensive breaking is precisely what they're trying to avoid! (Sorry, normally I wouldn't nitpick spelling when the meaning is clear, it was just a funny error!)
- maaku 13y ago
  Hah! I had to reread twice to spot the mistake. That's too awesome; I'm going to leave it as-is.
rkuykendall-com 13y ago
What about crashing it into the moon? Higher cost, but much less chance of earth contamination. We could then check it out with cheap robots.
- didgeoridoo 13y ago
  An object coming in from a rendezvous with Saturn would be traveling at a ludicrous speed. You would probably vaporize on lunar impact. The Earth's atmosphere can help slow it down to a reasonable velocity--otherwise you have to carry a lot more fuel to burn in a slow-down maneuver.
  - hrjet 13y ago
    Similar to how a swing-by is used to accelerate a space-vehicle, I wonder if a swing-by could be used to decelerate as well.
    - vilhelm_s 13y ago
      According to Wikipedia, the MESSENGER mission to Mercury used a complicated series of fly-bys of Earth, Venus and Mercury to slow down.
    - Tuna-Fish 13y ago
      It can. The boost is proportional to the cos(final exit trajectory in relation to the planet, velocity of planet) -- so if the probe leaves the planet opposite to the direction it goes around the sun, it slows down. (that is, the probe as whole can still orbit the sun in the same direction as the planet, it just needs to do it slower.
  - BrandonMarc 13y ago
    Ludicrous speed?! I bet they have hyperjets on that thing! (ducks)
fit2rule 13y ago
Send two missions, one with the capture device, the other with a functioning remote-controlled robot laboratory. Leave them close to the region, set them up to explore for 50 years or so. I know, I know, budgets. It'll 'never' happen. But what if we just send a nano-factory with its own assembly/disassembly abilities? Feasible, 5 - 10 years on from now? Well anyway, the point is: why bring it back, really? Just send more machines to do better jobs in space.

TrainedMonkey 13y ago

I doubt in orbit rendezvous with ISS would be safer and cheaper. It might be safer from planetary contamination standpoint, but complexity of such maneuver would handily offset that. On top of that there is a host of other issues due to the cramped space on ISS. For example: not enough space for proper isolation of sample, not enough equipment to properly study sample, and the fact that limited manpower would be available for examination. Regarding planetary contamination, with the amount of meteorites hitting ocean I do not think we have anything to worry about.

jmpe 13y ago
That makes sense. But regarding your last sentence: I'm not very fond of that risk analysis. Potentially introducing an alien aquatic micro-organism (that's what we hope to bring back, remember) into earth's system... No competition, paradise compared to its hostile home. No meteorite has ever been shown to carry life, but into this case we intend to deliberately introduce it, either controlled or uncontrolled. NASA can bill me for the extra cost for taking it to ISS instead of earth's surface.
- bausson 13y ago
  No competition? A life form which evolved in a (relatively) low-energy environment (low temperature, low light level, lower pressure) is more in hell than in a paradise. Earth organism evolved to make the best of available resources on Earth, be it energy or materials; the organism would be teared apart in no-time. That is, unless it is a highly intelligent and evolved life form with big environment alteration capacities, but then it might already be a problem, just one we aren't aware of.
civilian 13y ago
Eh, I've played KSP, an orbital rendezvous in LEO on your return isn't that hard. If you have enough precision and fuel leftover to start a safe decent, you have enough precision and fuel to dock with the ISS. I'm surprised that we aren't equally worried about contaminating Enceladus with terran microbes.

elnate 13y ago

In regards to the contamination, I don't think that would be a real risk. Earth life has spent billions of years both adapting and adapting to the environment to make it the best growing medium and even then it exists in exclusive bands. For example, put a polar bear in the desert or a fresh water fish in salt water. It is more likely that we would have to take extreme care not to kill any lifeforms we brought back than to worry about them killing us.

jmpe 13y ago
You're seriously underestimating this issue. - rabbits/cane toads in Australia [0][1] - Japanese knotweed [2] - Tumbleweed (yep, not as native as Hollywood suggests) [3] - Algae [4] ... and the list goes on and on, here's a top-100: http://en.wikipedia.org/wiki/List_of_the_world%27s_100_worst_invasive_species http://en.wikipedia.org/wiki/List_of_the_world%27s_100_worst... [0] http://www.youtube.com/watch?v=pgPhn4tYxJQ http://www.youtube.com/watch?v=pgPhn4tYxJQ [1] http://en.wikipedia.org/wiki/Cane_toads_in_Australia http://en.wikipedia.org/wiki/Cane_toads_in_Australia [2] http://www.environment-agency.gov.uk/homeandleisure/wildlife/130079.aspx http://www.environment-agency.gov.uk/homeandleisure/wildlife... [3] http://en.wikipedia.org/wiki/Kali_tragus http://en.wikipedia.org/wiki/Kali_tragus [4] http://plants.ifas.ufl.edu/node/89 http://plants.ifas.ufl.edu/node/89
TeMPOraL 13y ago
I don't think anyone is worried about space bears or space fish; but bacteria / viruses / other basic replicator forms have much bigger resistance to harsh environments.