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Lost in Space
"Jorge R. Frank" wrote:
A more likely answer is that if we ever send a manned craft to a deep-space target, it would likely be preceded by lots of unmanned craft. Look at Mars for example. When we finally get there, we will have a full orbital communications network, a Martian GPS I agree there will be robotic assets, but I don't think they will be as extensive as you paint it. A Martian GPS (MPS?) is a nice luxury but will likely be one of the first things axed when overruns start occurring on the manned side of the mission. The sad part is that, despite the limited utility of a M-GPS type of system, somebody will probably propose one and millions will be wasted on developing it. D. -- Touch-twice life. Eat. Drink. Laugh. -Resolved: To be more temperate in my postings. Oct 5th, 2004 JDL |
#12
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Lost in Space
"dean" wrote in message news:2006112309332116807-robodean@gmailcom... snip I was more hung up about the loss of communication with long term missions. It is conceivable that sometime, in a few decades, we may start undertaking long range space travel. I was just playing a thought experiment. What if? What if a spaceship went off to Europa and all its communication gear went dead. What would or could happen. But of course, at least for the very near future, you are totally right. I don't think we have a radar or visual track on deep space probes. I think without an active communication on the probe, we would loose it completely, i.e. it would become invisible to us. Danny Dot www.mobbinggonemad.org |
#13
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Lost in Space
wrote in message oups.com... snip Consider the Mars Observer back in 1992. This unmanned probe abruptly stopped communicating. There was a plan to point Hubble at Mars to take a look. Although Hubble could not see the probe, it would be able to see the glare as the probe fired up its engines to slide into Mars orbit. Are you sure about this? I wouldn't think the "glare" or those small engines could be seen by Hubble. Danny Dot www.mobbinggonemad.org snip |
#14
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Lost in Space
Danny Dot wrote:
Are you sure about this? I wouldn't think the "glare" or those small engines could be seen by Hubble. Hmm, I can't seem to find anything online to confirm this. On the other hand, the planet chart at www.heavens-above.com seems to indicate that there was about a 35 degree angle between Mars and the Sun from Earth on 21 Aug 1993. Hubble's normal cutoff is around 50 degrees (I can only find one reference to this). Which correlates with what I heard at the time which was that using Hubble was technically possible but not worth the extreme risk, given that the resulting information would likely not tell us how to rescue the probe. As for picking up the engine glare, I suspect that any such hypothetical observations would be a difference operation. Take a grossly over-exposed shot of Mars. Take a grossly over-exposed shot of Mars + Mars Observer. Mathematically subtract the two images. Look for non-random differences. One advantage of this sort of observations is that one is just counting photons, not trying to build a sharp image. So the uncorrected flaw in Hubble's mirror would not have made any significant difference. Another thing that would help is that one would be looking for the characteristic wavelength generated by the monomethyl hydrazine fuel in Mars Observer's engines. I've no idea what the spectra of burning monomethyl hydrazine is, but Hubble has got an extensive set of filters which could be juggled to get rid of as much background light as possible. |
#15
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Lost in Space
wrote in message ups.com... Danny Dot wrote: Are you sure about this? I wouldn't think the "glare" or those small engines could be seen by Hubble. Hmm, I can't seem to find anything online to confirm this. On the other hand, the planet chart at www.heavens-above.com seems to indicate that there was about a 35 degree angle between Mars and the Sun from Earth on 21 Aug 1993. Hubble's normal cutoff is around 50 degrees (I can only find one reference to this). Which correlates with what I heard at the time which was that using Hubble was technically possible but not worth the extreme risk, given that the resulting information would likely not tell us how to rescue the probe. As for picking up the engine glare, I suspect that any such hypothetical observations would be a difference operation. Take a grossly over-exposed shot of Mars. Take a grossly over-exposed shot of Mars + Mars Observer. Mathematically subtract the two images. Look for non-random differences. One advantage of this sort of observations is that one is just counting photons, not trying to build a sharp image. So the uncorrected flaw in Hubble's mirror would not have made any significant difference. Another thing that would help is that one would be looking for the characteristic wavelength generated by the monomethyl hydrazine fuel in Mars Observer's engines. I've no idea what the spectra of burning monomethyl hydrazine is, but Hubble has got an extensive set of filters which could be juggled to get rid of as much background light as possible. Nice post, Thanks. I am not going to say I know Hubble could not have seen the rocket plume. Danny Dot www.mobbinggonemad.org |
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