Orbital Express Launches Tonight

airshowfan writes "When a geosynchronous satellite is launched into space, no human ever gets to touch it again. This means that, other than for minor software issues, there is no way to fix it if it breaks, so it has to work perfectly, almost autonomously, for 20 years non-stop. There is also no way to refuel it once it's out of thruster fuel, the reason why it can't last more than 20 years even if it gets to that mark working very well, with batteries and solar cells still going, which is often the case. If only there were a robotic spacecraft in geostationary orbit that could change broken satellite components and refuel those older satellites, then satellites would be a lot less risky and would last a lot longer. Does this robotic spacecraft mechanic sound like science fiction? It launches tonight."

Comments

Who will refuel it?

[dgatwood]

The fuel has to come from somewhere. Repairing satellites is one thing. Refueling them is something else entirely.

Re:Who will refuel it?

[GrievousMistake]

It's not a "OMG they must have forgotten about that", it's a "I would like to know how they will handle that".
It seems most likely they will keep firing up expendable refuelers with most of its payload being fuel. A simple maneuverable fuel tank that could refuel a more long-lived and advanced refueler craft. Short of having a space tube or manufacturing fuel in space, they will need to shoot up a rocket to get the fuel up there anyway.
That's all rather far into the future, anyway. These seem to be just preliminary experiments.

I can't believe this guy

[TubeSteak]

"I think it' extremely valuable for the entire space arena," [USAF Lt. Col. Fred Kennedy, project manager for Orbital Express] said of Orbital Express' goal, adding that the mission could help ease the stringent requirements of long-life satellites. "Maybe you can accept a level of imperfection that will allow you to go up later and perform upgrades and perform repairs, and put more propellant onboard to get the job done. That will be a sea change in the way we do business."

Dude, wtf?
This is rocket science, not something you'd patch with Windows Update.

Which is more expensive:
A) Build the satellite correctly the first time around
B) Build the satellite cheaply & then pay to get it fixed in orbit

I know which is better for Lt. Col. Fred Kennedy's bottom line.

Re:I can't believe this guy

[susano_otter]

"The perfect is the enemy of the good."

A good geostationary satellite and a good refuel/repair satbot may be cheaper than a near-perfect satellite and no repairbot.

Re:I can't believe this guy

[minus_273]

"I think it' extremely valuable for the entire space arena," [USAF Lt. Col. Fred Kennedy, project manager for Orbital Express] said of Orbital Express' goal, adding that the mission could help ease the stringent requirements of long-life satellites. "Maybe you can accept a level of imperfection that will allow you to go up later and perform upgrades and perform repairs, and put more propellant onboard to get the job done. That will be a sea change in the way we do business."

Dude, wtf?
This is rocket science, not something you'd patch with Windows Update.

Which is more expensive:
A) Build the satellite correctly the first time around
B) Build the satellite cheaply and QUICKLY ; then pay to get it fixed in orbit

I know which is better for Lt. Col. Fred Kennedy's bottom line. there i fixed it for you

Re:I can't believe this guy

[FleaPlus]

Which is more expensive:
A) Build the satellite correctly the first time around
B) Build the satellite cheaply & then pay to get it fixed in orbit

I'm not so sure things are as clear as you're suggesting. Extreme redundancy and quality assurance costs a lot. I'm sure there are many circumstances where option B is cheaper.

Re:I can't believe this guy

[Nyeerrmm]

It's not a matter of being correct or incorrect, it's a matter of tolerances, precision, and risk management.

Any time you build a satellite, you're just hedging your bets. It could get blown up on launch (there's a finite chance of that, say ~5%, but thats just a guess, but i know its somewhere in that order of magnitude,) it could get hit by micrometeors, something could have gone wrong in manufacturing that got missed in inspection. Hell, if everything goes great then you have to shut it down arbitrarily at its predefined end of life, because you cant keep it on station.

Basically, what it comes down to is that any engineering requires assumptions and taking some risks. Most of the time you can assume that you'll have a chance to correct things, except of course in space-borne applications. But really my main point is that there is no perfectly engineered solution, but by requirement satellites are as close as you can get within budget. This technology simply allows you to do it for cheaper, because it means that failures can be more common because you have an option to fix it.

Re:There is no way to fix it if it breaks?

[AKAImBatman]

Roughly a 22,000 mile technicality.

Technically distance is just a technicality. For the real differences, let's talk Delta V.

Re:Woot

[Anonymous Coward]

"There is also no way to refuel it once it's out of thruster fuel, the reason why it can't last more than 20 years even if it gets to that mark working very well, with batteries and solar cells still going, which is often the case."

Thanks slashdot, for one of the most grotesque and ambiguous run-on sentences I have seen in a damn long time.

PS 3 anonymous.

Re:There is no way to fix it if it breaks?

[rbanffy]

Good point. Add to the list "about half the mass of the shuttle in shielding that could be used as propellant as far as you don't use too much of it". They could use nuclear-thermal propulsion, but good luck with the paperwork necessary for flying a nuclear reactor that size into space. Hell. _I_ would be worried having such a device going up on a shuttle. The failure-rate is way too high for that kind of stuff.