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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.
Would this allow for more complex satellite design, knowing that in-orbit maintenance is available? Could NASA charge commercial industries and other governments for maintenance service of their satellites? If so, would this be a feasible source of moderate funding? Will companies wanting to send up satellites now have to sit through the "extended warranty" sales pitch too?
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.
Quark (TV series)
This isn't a bad idea. Especially that the normal satellite lifespan is only about 15 yrs.
This makes me wonder if spy (or other sensitive) satellites have tamper-detection built in.
This makes plenty of sense if the next generation of satellite were to standardize some things to plan for this, but is extremely unlikely to work for current satellites that were not designed with service in mind. The current satellites don't even have simple things like standardized and accessible fuel fittings (since it was never expected that this would happen and they were considered disposable) or even physical hold points where a service device could latch on. A good modular design for module replacement that allows for access and plug-ability would obviously help too, even if specific modules had to be lifted into space before a service mission.
Before N.A.S.A. wastes too much of its ever dwindling budget (insert here comment about how we have so much money that we can give the poor free Internet and Obamaphones), they should create a set of standards and see if they can get the industry to willingly adopt them with the expectation that it would facilitate service in the future. Once a fair number of devices that were deigned planning on being able to be serviced if a service station were ever deployed are in orbit, then putting that station in space could make sense.
I'm an American. I love this country and the freedoms that we used to have.
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.
Yes, Solar Max was the first to be repaired. And there were some other satellites that were retrieved and brought back.
But (yes there are always bad excuses) cost of flying Shuttle is far more expensive than the satellite itself. I remember in 1970s/1980s there was lots of talk about space tugs, then poof all such articles disappeared. Later in 1990s in a project management class, instructor mentioned a parametric study on space tugs resulted in energy changes to change orbits from typical 250mile at 28.5 deg Shuttle orbit to get to various satellites will take more energy than to send a spacecraft to the Moon. Shuttle could change orbit inclination but not by much (I think about 1 deg). Damn physics again prevents science fiction becoming reality.
On a side note, Shuttle capable of retrieving satellites was something the Soviets ***did not*** like as their recon birds were ripe for pickings.
On NASAwatch someone posted this insightful comment:
"I blame most of the destination argument on the creation of the Mars underground in the 1980's. Prior to that NASA was focused on using the Shuttle for industrialization in LEO with projects like demonstrating the repair and return of satellites, building structural items in orbit, tethers, etc., all logical starting points for building a Cislunar industrial capability that would have given us the Solar System. NASA didn't even have plans to send robots to Mars. By advocating that we needed to skip the Moon and go rushing off to Mars they started this entire useless destination debate that has paralyzed space policy ever since."
mfwright@batnet.com
Resurs-P No.2 Can we stop at a rest stop
russian space agency you just stopped like 2 days ago....
Resurs-P No.2 yeah but i have to go again...
russian space agency fine Resurs-P No.2 but make it quick you need to be on the other side of the planet soon...
NOAA-4 SATCOM!!! NOAA-16 wont stop touching me.
stcom: NOAA-16 stay on your side of the orbit.
NOAA-16 ARE WE THERE YET I NEED TO STOP
stcom no you orbit the poles you'll be there in another hour or so. just be quiet
NOAA-19 my Solar Backscatter Ultraviolet Spectral Radiometer is sore can we stop at a rest stop
stcom damnit NOAA-19 not until you stream the rest of your data.
Good people go to bed earlier.
This should answer your question https://what-if.xkcd.com/58/
Basically, the energy intensive part of getting to orbit isn't getting high, it's going fast enough horizontally. You basically have to be going so fast that the ground falls out from under you (due to the curvature of the Earth) before you can hit it.