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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.
Sounds like they could use some real money any day now. I'm all for Monopoly but have you seen the shit they try to pass off over there?
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?
Repairing them sounds nice, but spares are a significant problem, orbital spots in GEO are precious, and each generation of satellites is substantially more capable. For physics-limited satellites, which is to say imagery satellites, refueling makes sense. However, every other category of satellite I'm aware of has significant improvements with each generation of launch.
Much more plausible for that small set of satellites is a mid-life docking, where the mid-life craft is much smaller, and has just consumables ... fuel, thrusters, reaction wheels and batteries. Better (more efficient) batteries will help with degrading solar panels, thrusters do occasionally fail, and reaction wheels are still pretty damn unreliable. Having exactly one docking operation in the life of the satellite is much simpler than "maintenance", though the added weight, complexity and failure modes will compromise the sv in some way.
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.
We need orbital tug boats that are nuclear powered. Bring them to low earth orbit to refuel, spend the rest of the time pushing other objects in orbit. Can even be used to send space probes on their way.
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.
Hmm, this was what the US shuttles were supposed to have been able to do. In practice, they could only reach low earth orbit, but they did service the Hubble at least.
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.
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.
If someone knows a slashdot dev, give them a good slap in the face for me. Thanks.
Is there a reason we do not use a slow speed to orbit?
Say, a large zeppelin floats as high as possible, fires a jet engine to go higher, then a rocket to leave the atmosphere.
Or couldn't a zeppelin carry a Xenon Thruster engine?
Does it have to be short duration, high thrust; never long duration, low thrust to get to orbit?
I am the unwilling control for my Origin.
Human joyriding in "space" (LEO) is what keeps the funds flowing, so NASA trots out another manned boondoggle. Our space program is effectively funded by children who want to see astronauts stunting in zero G. Meanwhile, all of the significant space science is accomplished by funding-starved unmanned missions that the kids find boring. Manned space funding should be cut to ZERO, and an aggressive robotic and unmanned program should be initiated with extensive international cooperation.
What about the radiation problem. How are the humans going to be protected from the radiation theses satellites have absorbed in there time in orbit?
Jack of all trades,master of none
Now if we could only get some kind of a station, a space station if you will, in orbit to allow this. And wouldn't it be better if it were an international type of operation, so that any nation could get servicing there? They would need to pay of course, or at least be partners in the space station.
Therefore I propose the following: Let us make a Space Station International (SSI). The Americans and Russians should be part of it. And the Europeans, Canadians, Australians, Chinese. Let's get the Indians on board if we can. And that's just for starters, anyone should be able to join, so long as they have appropriate usage and costing agreements.
Yes, an SSI, that's the ticket!
So... repair and refuel Hubble?
Or if they can't do that, let SpaceX go up on their own dime and claim salvage?
Or let Google contract a SpaceX flight or two, go up, and claim salvage?
For NASA to build an orbiting depot to refuel/patch its own satellites, and even secret military devices of NATO countries --- the cost/benefit analysis of what is likely to happen can be completely considered --- and no one's job is at stake. Within a government or military entity everything is considered to be a 'mission' that is either a success or a failure.
But the moment this NASA facility drifts into range of someone else's corporate private property... the clouds will part and the night sky will fill with lawyers. Now there is a product being delivered. It's easy to imagine a utopian scenario where everything goes all right, the happy satellite is refueled and goes on its merry way, and its owner shares some of its years of '$free$' money with NASA to help recoup its expenses.
One time fixed price for refueling, or sliding scale based on projected income from satellite? Projected by whom? What if the satellite is still within its original life expectancy? Will the corporation be able to offset the expense of its early demise with the profit from its extended lifespan plus refuel cost... or will it it's profitable orbit began to decay towards Chapter Seven? Because money is involved even a successful mission is not that simple. A large part of the complexity arises because major capital projects are launched for a per-determined time span and a certain expected fixed rate of return. Once those decisions are made corporate boards of directors and the banks behind them are 'locked in' to these projects, win or lose. The scenario where a malfunction or propellant loss takes a satellite out of service has been planned for. It requires corporate courage and applied risk to modify those terms. And courage is rare these days.
That was success. Now on to the risks of failure. It is similar to the escalation of complexity in 1 vs. n-body problems. This would probably be practical for geostationary orbits only, since our facility has lots of mass and finite energy and time to maneuver between jobs. Still there are more things to go wrong than right. Most satellites are 'deployed' with appendages unfolded... how to avoid damaging them? How to tether satellite and repair vehicle safely? The refueling process involves re-pressurization through couplings. What happens if/when tethers snap, couplings fail or tanks burst, escaping propellant slams the satellite against the vehicle, damaging it? What if the failure arises from a corporation or government failing to divulge some key piece of information about the satellite?
Now I'm the last person to go on about planned obsolescence as if it is a good thing, but in geosynchronous orbit it's kind of a good thing. If something has turned to shit and is out of service, it really is best, and safest, to have one certain kind of maintenance satellite up there --- a killer-pusher death satellite to disable and push the junk out of geosynchronous orbit and away from the other precious satellites.
Otherwise the first thing that goes Horribly Wrong will result in a disabled satellite and a satellite repair facility both careening across the heavens. What an awesome spectacle of corporate liability that would be. You could even spot the liability with the naked eye.
<blink>down the rabbit hole</blink>
I suspect this idea will never reach fruition because