Long boot time
-
http://www.informationweek.com/news/government/mobile/240003883[^]
Quote:
The computers on NASA's Curiosity rover are being rebooted as the spacecraft approaches Mars for its Aug. 5 landing. The process, which occurs over four days, resets Curiosity's primary and backup systems to their default state in advance of a landing sequence that leaves little room for error.
Wow, a four day reboot process? :wtf: and I hear people complaining about 5 minutes :cool:
Be The Noise
It's not quite as slow as curiosity; but we've got some equipment that IIRC takes 2 working days from power on to ready to use: 24 hours to reach thermal equilibrium from a cold start, and a full working day afterwards to run self calibration/test procedures.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, waging all things in the balance of reason? Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful? --Zachris Topelius Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies. -- Sarah Hoyt
-
It's not quite as slow as curiosity; but we've got some equipment that IIRC takes 2 working days from power on to ready to use: 24 hours to reach thermal equilibrium from a cold start, and a full working day afterwards to run self calibration/test procedures.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, waging all things in the balance of reason? Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful? --Zachris Topelius Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies. -- Sarah Hoyt
Here on earth, my sister owns a pizza shop with a charcoal-fired brick oven that runs at about 900 degrees F. When it is shut down for the once-in-three-years-family-vacation, it takes almost two days to coax it back to operating temperature... very slowly, so as to not crack the brickwork!
-
"Have you tried turning it off and back on again?" "No, I haven't. See you in 4 days." Seriously though, I don't like the idea of rebooting billion dollar pieces of equipment as they are flying through space at 13,000 mph towards a very large, hard object.
wizardzz wrote:
Seriously though, I don't like the idea of rebooting billion dollar pieces of equipment as they are flying through space at 13,000 mph towards a very large, hard object.
Its become standard practice to launch with the "firmware" not yet complete. Its uploaded enroute.. and then updated as necessary once the rover's on the ground. Technically, even landing code could be uploaded enroute. Its not like it can be tested against anything other than a simulator prior to being used anyway :)
We can program with only 1's, but if all you've got are zeros, you've got nothing.
-
wizardzz wrote:
Seriously though, I don't like the idea of rebooting billion dollar pieces of equipment as they are flying through space at 13,000 mph towards a very large, hard object.
Its become standard practice to launch with the "firmware" not yet complete. Its uploaded enroute.. and then updated as necessary once the rover's on the ground. Technically, even landing code could be uploaded enroute. Its not like it can be tested against anything other than a simulator prior to being used anyway :)
We can program with only 1's, but if all you've got are zeros, you've got nothing.
patbob wrote:
Technically, even landing code could be uploaded enroute. Its not like it can be tested against anything other than a simulator prior to being used anyway
Correct me if I'm wrong, as I've done very little research as to the testing they did, but isn't it quite simple to test the landing software? I mean, most of the cost was in getting there and the development of the equipment to be used. How much more would it cost to build a dummy rover that contains all the landing gear, etc, and include equal weighted dummy equipment, maybe a few accelerometers?
-
patbob wrote:
Technically, even landing code could be uploaded enroute. Its not like it can be tested against anything other than a simulator prior to being used anyway
Correct me if I'm wrong, as I've done very little research as to the testing they did, but isn't it quite simple to test the landing software? I mean, most of the cost was in getting there and the development of the equipment to be used. How much more would it cost to build a dummy rover that contains all the landing gear, etc, and include equal weighted dummy equipment, maybe a few accelerometers?
-
Yeah, building an extra rover/landing assembly would be cheap, but building an extra planet with 1/3rd the gravity and 0.6% of the atmosphere could be kind of expensive....
Ok, now here me out. Would it have been possible to send both up in the same rocket, (I'm assuming most of the cost is getting out of Earth's orbit, near gravitational pull, atmosphere, etc). Send the dummy one ahead by a few days with a little rocket charge when just a few days out. Let it go first, if it lands, stay with the protocol, if not, use plan B!
-
Ok, now here me out. Would it have been possible to send both up in the same rocket, (I'm assuming most of the cost is getting out of Earth's orbit, near gravitational pull, atmosphere, etc). Send the dummy one ahead by a few days with a little rocket charge when just a few days out. Let it go first, if it lands, stay with the protocol, if not, use plan B!
Hmmm... Interesting idea. Couple of problems I see: 1. Let's say the first one crashes but manages to send back enough telemetry that you can figure out what went wrong. What do you do if the problem is something mechanical that you can't compensate for by adjusting the firmware? What do you do if the plan B you had doesn't address the failure mode that actually occurred -- now you only have 4 days to devise a new landing procedure, code it up, test it, and upload it. That's a serious time pressure. 2. Do you actually save anything by sending two at once? The second one has to have the same mass as the first one. So you need twice the lifting capacity. If you already have the spare lifting capacity in the lift vehicle you are using, why not use it to lift a low risk payload like cargo for the space station? Then you are sharing the lift costs with some other program and only paying for the actual mass you are lifting. The only thing you save is the time it takes to get a second probe to Mars if the first one crashes -- but if you have to do that, at least you have plenty of time to analyze the previous failure and devise and test a new solution. Your not in the desparate time crunch of having to come up with something in a couple of days before your probe crashes into Mars. Arriving at Mars two years later isn't significant on the geological time scale of Mars.
-
Are these mutually exclusive? ;P
I don't think so, see you in 4 days, Ctrl-Alt-Supr. X|
CEO at: - Rafaga Systems - Para Facturas - Modern Components for the moment...
-
It's not quite as slow as curiosity; but we've got some equipment that IIRC takes 2 working days from power on to ready to use: 24 hours to reach thermal equilibrium from a cold start, and a full working day afterwards to run self calibration/test procedures.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, waging all things in the balance of reason? Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful? --Zachris Topelius Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies. -- Sarah Hoyt
I bet they run MS-DOS... :laugh:
CEO at: - Rafaga Systems - Para Facturas - Modern Components for the moment...
-
I bet they run MS-DOS... :laugh:
CEO at: - Rafaga Systems - Para Facturas - Modern Components for the moment...
HP True64 Unix on Alpha chips for the control computer. I've no idea what, if any, form of embedded computing is in the backend hardware.
Did you ever see history portrayed as an old man with a wise brow and pulseless heart, waging all things in the balance of reason? Is not rather the genius of history like an eternal, imploring maiden, full of fire, with a burning heart and flaming soul, humanly warm and humanly beautiful? --Zachris Topelius Training a telescope on one’s own belly button will only reveal lint. You like that? You go right on staring at it. I prefer looking at galaxies. -- Sarah Hoyt