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Mars Recon Orbiter Nearing Mars Orbit
DarkNemesis618 writes "The Mars Reconnaissance Orbiter, launched 12 August 2005, has nearly completed its 7 month journey to the Red Planet. At 9:24 pm GMT, the MRO is scheduled to fire its thrusters to slow it down enough to enter Mars orbit. NASA scientists are concerned about this final step for the orbiter as Mars has a history of 'swallowing' probes, orbiters, and landers sent to the Red Planet. What makes it more difficult is the delay time between NASA computers on earth and computers on board the orbiter. There is about a 12 minute delay between when data is sent from Earth to the time the orbiter's receivers pick it up, and vice versa. Because of this, onboard computers will handle the burn which adds to the risk."
SpaceFlightNow has the play-by-play - more exciting than watching grass grow ;-)
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Let's see if we can catch up with the little red martians... Mars Scorecard
link to JPL Mission Control webcam http://137.78.244.28/axis-cgi/mjpg/video.cgi?camer a=&showlength=1&resolution
NASAtv coverage has begun. http://www.nasa.gov/multimedia/nasatv/
Realtime Dopplar radar from MRO: http://mars.jpl.nasa.gov/mro/realtime/mro-doppler_ lg.html
This is gonna be fun!
I don't see that in the ALSJ. They got a quantity light but Armstrong had the vehicle on the ground within the required 60 seconds.
Double-checking that, it looks like you're right. I'm probably thinking of the fact that there were several situations which called for a possible abort (including the 1201 program code which resulting in an abort during the last simulator run).
As a result if they have to abandon a shuttle in orbit there is absolutely no way to recover the vehicle.
More or less. I can't say I disagree with their decision, though. The Shuttle was the most complex spacecraft built to date. Anything that could be done to improve safety was a good option consider. I'd imagine that a new vehicle like the Shuttle would probably carry an arming switch that, once activated, would allow computer control over the gear.
there must be hundreds of things which the computers could break during the flight which would cause loss of the mission.
Yes and no. Most everything else the computer might do is recoverable. If it begins applying the wrong control surfaces, manual control can be applied. If it miscalculates a burn, mission control or the crew can override with new parameters for a correction burn. If it begins opening the bay doors, they can be reclosed. Only the landing gear is completely unrecoverable, as it is deployed with explosive bolts. (!) Thus, even under the best conditions (deployment in orbit), there would be nothing the crew could do to fix the situation.
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Orbit is now confirmed. Still need to collect telemetry to determine how close the orbit is to the desired one, but things are looking quite good.
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The MRO is succesfully in orbit! Congrats to everyone at JPL.
It always gives me goosebumps watching these events where mission control goes from joking and chatting to pin-drop quiet just before re-acquisition of signal and then the yells and whoops of joy when they lock on.
Great stuff!
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My understanding is that the landing gear is definitely one shot. It is powered by a spring which is compressed during the stacking process on the ground. I think the confusion is with the release mechanism. There is a reusable system (perhaps hydraulic) but the explosive bolts are a destructive backup. I think the explosive devices are wired to fire automatically if the gear does not go down when commanded.
After the last shuttle disaster there was some speculation that the gear may have accidently deployed during reentry. But this was disproved.
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