NASA delays decision over Shuttle repair
Weighing up risks
NASA has put off making a decision about repairing a hole in the insulation under the space shuttle's wing until tomorrow, according to reports.
If the repair is needed, the fix will take place on the next spacewalk, slated for Saturday.
The Houston Chronicle reports that the team aboard Endeavour asked mission control whether another spacewalk was likely. Commander Scott Kelly was told: "We have no idea which way the wind is blowing at the moment."
The gash in the thermal tiles is roughly three and half inches long, by two inches wide. In one area, a one inch wide strip, the tile has been cut right through, exposing a part of the thermal fabric that covers the shuttle's frame.
The aluminium frame cannot get hotter than 350 degrees, NASA says. Simulations suggest it will heat to around 325 degrees, with the worst of the heat of re-entry skipping over the "wound".
Initial tests suggest a repair will not be needed, but this is clearly not an decision NASA can afford to get wrong. Although engineers are not worried about another catastrophic failure, as with Columbia, they are worried that over heating the area could mean long and expensive repairs once the shuttle is back on the ground.
NASA would prefer to avoid the risk of another spacewalk if it is not absolutely necessary. Leaving a spacecraft in orbit is not a safe thing to do, after all. But concerns are probably heightened, especially after the latest spacewalk was cut short when one of the astronauts noticed a two inch gash in his glove.
NASA said Rick Mastacchio was never in any danger, since only the glove's top two layers (of five) had been torn. But the reason for the tear is not clear: it could be sharp edges on the space station, but because it is the second torn glove in the last three missions, and managers are worried the suits might be showing signs of age.
Those in charge of planning the spacewalks said they would prefer not to have the team take another jaunt outside until they know why the glove tore. But the big boss, John Shannon, said he'd have no hesitation in ordering astronauts out the airlock if a repair is needed. ®
Real Time Systems
"and the speed-of-light latency delay is in the order of a tenth of a second. That might be a problem if you were trying to play high-speed video games by remote control with the droid, but nobody would design an engineering procedure that required lightning-fast reflexes from someone encumbered in a spacesuit in zero G!"
It seems you have never used satellite comms, have you? Pinging on those is on the order of 1000ms or higher. Actually video games online are just the kind of thing you should be using to benchmark that kind of handling, as you are responding to stimulae that has already happened about 400ms ago. You're bound to screw up.
Mission-critical stuff where lives depend on the response time are called "real-time", which have near-zero response time. Being en zero-G ups the risk ... you could theoretically push yourself away from your spaceship and drift to your death ... slooooooowlyyyy.....
Arooga! Arooga! Nutter alert! Nutter alert! [ @Repairs thread ]
Whoah, there's always one, ...
" Imho, nasa has astromech droids in his labs. "
... in your *opinion*, Star Wars was real, and R2 units actually exist, and NASA is a man, not an organisation? How do you get from that starting point to the conclusion that your opinion is of any value or interest to anyone other than a student of psychology? Listen up, dude, I believe in freedom of speech, and so everyone has the right to their opinion, but that doesn't mean you have the right for your opinion not to be a load of inane bullshit: you have to *earn* that, by not being stupid.
... and then just when you think there can only be one, he is joined by another ....
"As for the astromech droid idea, it sounds good, except for one small flaw: Speed of light latency. If there was any step that was time sensitive, that extra delay could be very bad."
I'm crushingly disappointed here, you were doing so well, just as far as "good, except for one small flaw". Then you completely lost the plot, because just when we were hoping you'd strike a blow for sanity by saying "one small flaw: there's no such thing as an astromech droid", but instead you skate over the massive massive HUGE impossibility of a flaw, and tie yourself up in a knot of gibberish: speed of light latency and time-sensitivity. Perhaps in your imagination the Shuttle is an interplanetary craft of some kind, but in *this* universe, it's a low-orbit craft, and the speed-of-light latency delay is in the order of a tenth of a second. That might be a problem if you were trying to play high-speed video games by remote control with the droid, but nobody would design an engineering procedure that required lightning-fast reflexes from someone encumbered in a spacesuit in zero G!
From the Early Days of Spaceflight
The comment about the age of space suits and the implication that they're being re-used on cost grounds made me think of the John Glenn quote " I was thinking that the rocket had twenty thousand components, and each was made by the lowest bidder".