Slashdot Mirror
Orbiting 'Rest Stops' Could Repair Crumbling Satellites
astroengine writes: Satellites are numerous, vital to many modern activities, and incredibly expensive to build and launch. They're constructed with redundancy and simplicity in mind because if something goes wrong after the satellite reaches orbit, we can't do much to help it. Now, NASA is talking about building an orbital service station that can perform maintenance, repair, and even refueling operations on these satellites. "Is there a way working with humans and robots together to extend the useful life of satellites, by fixing them and by not allowing fuel to spill out, but give it more propellant, close it up and send it on its way?," said Benjamin Reed, deputy director of the Satellite Servicing Program Office at NASA's Goddard Space Flight Center. "Yes, We have the technologies to be able to do it."
The technology to safely capture and repair a satellite that may not be in a position to help you(no fuel, engines offline, software issues, etc.) presumably doesn't differ so very much from that required to capture and modify somebody else's satellite, unless it is in the position to evade you with some enthusiasm, or otherwise make a nuisance of itself.
It would be a tad tricky to snag somebody else's satellite without ground control noticing that something is amiss; but the first time a satellite gets snagged 'on humanitarian grounds', purely to safeguard its orbit from possible debris of course, I predict some exiting diplomatic fun.
Of course, the "rest stops" with their stockpiles of fuel and parts will probably be massive structures, so we'll also need "tug boats" to transfer the satellites from their original orbit to one that can dock with the rest stop, and then return it to it's designated orbit again after repair and refueling. Still far less energy-intensive than sending up a replacement satellite though. And if only refueling is needed then it's probably easier still to outfit the tug with a refueling waldo that can mate with a standardized fuel receptacle on the satellite - then the tug only has to make a single trip from the rest stop/fuel depo to whatever wonky orbit the satellite is in, and the satellite itself need never move at all.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
This makes me wonder if spy (or other sensitive) satellites have tamper-detection built in.
But would repairing a satellite be cheaper than just launching a new one?
"First they came for the slanderers and i said nothing."
The huge problem is orbital mechanics. The delta-V difference between satellites is enormous. Polar orbit, geosynchronous orbit, low-earth orbit, etc, etc. The difference in velocity between them is more than any satellite or service vehicle could realistically overcome (assuming you want to visit more than one satellite every couple decades). Satellites in geostationary orbit might be doable, because they all have to orbit relative to the earth's rotation, so traversing from one to another might be reasonable. However they are so far up there that it would still require covering a lot of distance to get from one to another.
Better known as 318230.
This would probably be useful only for groups of satellites in the same orbital plane. The application that comes to mind is all the satellites in increasingly crowded geostationary ("Clarke") orbit, with the orbital plane going through the equator. Orbital plane changes are one of the most expensive maneuver there are in orbit. (This was one of the criticisms of the movie "Gravity". The only way a space shuttle can get from the Hubble's orbit to the ISS orbit is to land and get re-launched into the proper orbital plane. Doing it in a backpack? Ludicrous.)
A satellite repair bot making its rounds through Clarke Orbit could be extremely useful.