Quote from: simonbp on 11/10/2011 10:25 pmI know someone doing radar studies of Europa with the Goldstone 70-m. So yes, lots of power.Slightly off-thread, but do you have a reference/URL for that? I like to keep up with long-range radar capabilites.
I know someone doing radar studies of Europa with the Goldstone 70-m. So yes, lots of power.
If so - can a burn on the escape stage now be programmed back to the proper trajectory? s/c controls all escape stage functions?
During ground tests the onboard computer worked for no more than 6 hours before hanging. Last patch was applied at Baikonur. My question is, why had we to launch an inoperable spacecraft?
Quote from: Art LeBrun on 11/11/2011 03:39 pmIf so - can a burn on the escape stage now be programmed back to the proper trajectory? s/c controls all escape stage functions?The modified Fregat controls such things, and its uplink antenna is blocked by the drop tank...
Quote from: HIPAR on 11/11/2011 01:28 pmBut after 60 years of advanced rocket science, how does one get stuck in low earth orbit?Because rockets are still built by humans.
But after 60 years of advanced rocket science, how does one get stuck in low earth orbit?
So after solar panel deployment did the s/c command alignment on the sun? Wouldn't modified Fregat try to counteract a cruise mode command?
I understand there's really no way this would ever happen in today's environment (fiscal, safety, technology, etc), but out of curiosity, what is the delta-v between this probe and ISS? They are, after all, in pretty close to the same inclination and both in LEO (though different altitudes).
Now, IIRC, there is no hardware connection between S/C and EDS guidence computers, so you basically have the S/C and EDS fighting over alignment without any dialogue between them. One was pushing in one direction and the other pushing back until either the RCS prop is exhausted or (as appears to be the case) the un-programmed contingency caused an unrecoverable crash of both vehicles' guidence systems.
Not sure if this is true, but... QuoteDuring ground tests the onboard computer worked for no more than 6 hours before hanging. Last patch was applied at Baikonur. My question is, why had we to launch an inoperable spacecraft?
Quote from: HIPAR on 11/11/2011 01:28 pmBut after 60 years of advanced rocket science, how does one get stuck in low earth orbit?I imagine you do it in a similar manner to the CONTOUR spacecraft, which managed to blow itself apart while trying to leave Earth orbit.
Reflecting on things, this is going to look even worse if the Mars Curiosity launch gets off to a good start. It's damaging to the image of the Russian scientific community.
Maybe some heads do need to roll, so to speak, to get things moving in the right direction again. But, all programs suffer losses. If this is a loss, let's hope that it's a blip on the road to a successful unmanned program.
Quote from: Robotbeat on 11/11/2011 03:28 pmI understand there's really no way this would ever happen in today's environment (fiscal, safety, technology, etc), but out of curiosity, what is the delta-v between this probe and ISS? They are, after all, in pretty close to the same inclination and both in LEO (though different altitudes).It has nothing to do with the "environment". Orbital mechanics and lack of control prevent it.
Quote from: ugordan on 11/11/2011 01:32 pmQuote from: HIPAR on 11/11/2011 01:28 pmBut after 60 years of advanced rocket science, how does one get stuck in low earth orbit?I imagine you do it in a similar manner to the CONTOUR spacecraft, which managed to blow itself apart while trying to leave Earth orbit.I'd have to go back and look again (although Bob Farquhar's new book does have info on CONTOUR), but I think they suffered from the extremes of "faster, better, cheaper," meaning insufficient ground testing.
Quote from: Jim on 11/11/2011 04:24 pmQuote from: Robotbeat on 11/11/2011 03:28 pmI understand there's really no way this would ever happen in today's environment (fiscal, safety, technology, etc), but out of curiosity, what is the delta-v between this probe and ISS? They are, after all, in pretty close to the same inclination and both in LEO (though different altitudes).It has nothing to do with the "environment". Orbital mechanics and lack of control prevent it.I understand that it is simply not an option at all. But I am interested in how far ISS and Phobos-Grunt are in delta-v terms (i.e. orbital mechanics).