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NASA Working On Refueling Satellites

Soulskill posted about 2 years ago | from the fill-'er-up dept.

NASA 116

cylonlover writes "Geostationary satellites cost a fortune and, despite their sophistication, they break down or eventually run out of propellant to keep them oriented. This is unfortunate when the nearest garage is back on Earth, so NASA wants to remedy this with an orbital version of roadside service. The space agency is developing a service robot that can visit ailing satellites and refuel or even repair them on the spot. The refueling program is already at an advanced enough stage that a technology demonstrator called the Robotic Refueling Mission (RRM) was delivered to the International Space Station (ISS) in July of last year. The RRM was installed on a temporary platform outside the station. NASA's Goddard Space Flight Center wants a robot capable of carrying out what it calls the five 'Rs' – refueling, repositioning, remote survey, component replacement or repairing – on any satellite that might require its services."

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Headline: NASA WANTS MONEY (-1)

Anonymous Coward | about 2 years ago | (#41728269)

Quit wasting our tax dollars on this boondoggle when people are dying from lack of healthcare.

Re:Headline: NASA WANTS MONEY (1, Offtopic)

Metabolife (961249) | about 2 years ago | (#41728371)

Quit wasting your time posting on Slashdot while people are starving in Africa.

Re:Headline: NASA WANTS MONEY (-1)

Anonymous Coward | about 2 years ago | (#41728409)

Hypocrite!!!

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41728643)

I am starving in Africa and post on /. to take my mind off this fact. You insensitive clot!

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41730581)

US tax money for US related projects. I don't want to be an asshole but, Africa can start spending their tax money on buying foods so people wouldn't starve.

Re:Headline: NASA WANTS MONEY (1)

khallow (566160) | about 2 years ago | (#41728403)

Well, until someone figures out how to cure old age and its illnesses, we'll all continue to die from lack of healthcare. And to fix that is going to take more than just money.

Re:Headline: NASA WANTS MONEY (1)

rickb928 (945187) | about 2 years ago | (#41728853)

That's not lack of healthcare.

Re:Headline: NASA WANTS MONEY (0)

khallow (566160) | about 2 years ago | (#41731655)

Sure, it is. I think the simplistic commodification of health care policy is a terrible thing. It's treated like a bag of fries or a barrel of oil. Either you have it or you have a lack of it.

What we should be focusing on is health care outcome. The actual benefit not the pretense of health care. To observe as the original troll did, that people die from lack of health care is to ignore that people also die even in the presence of health care.

My view is that privately, you should be able to do whatever you want with your money and your life. But publicly, if the medical activity doesn't have obvious large benefits to society, such as immunizations, prenatal care, or treatable illnesses that can result in decades of good life quality at a modest cost, then it's not health care but health theater and I want no part of it.

Re:Headline: NASA WANTS MONEY (1)

rickb928 (945187) | about 2 years ago | (#41732715)

Well that's effed up

I'm responding to the 'cure for old age' concept. If you're proposing that we reevaluate the sometimes huge expenses in 'end of life care', be prepared to place a money value in someone's life. Me, I'm pretty sure my wife values knee replacement research enough to support it, since because of knee implants she is able to go up stairs without assistance. And she's 59 years old. A car accident started her knee problems when she was in her 20s. Insurance is an imprecise financing method, so do name me a better one.

You seem to be advocating some dual tiered form of healthcare financing. I'm not very hopeful that will work out, but please explain in more detail.

Re:Headline: NASA WANTS MONEY (5, Insightful)

K. S. Kyosuke (729550) | about 2 years ago | (#41728505)

Quit wasting our tax dollars on this boondoggle when people are dying from lack of healthcare.

[sarcasm warning] Yes, because satellites are never used for saving lives. [end of sarcasm warning]

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41728751)

You just don't get it: there is no real difference between a refueling satellite and a regular satellite. That is what OP meant.

-A.C.

Re:Headline: NASA WANTS MONEY (1)

khallow (566160) | about 2 years ago | (#41728881)

You just don't get it: there is no real difference between a refueling satellite and a regular satellite. That is what OP meant.

I doubt it. I believe the OP just was trolling. As to your assertion, the purposes are different and that in turn leads to functional differences (such as larger propellent storage in the refueling satellite) and developments of appropriate technologies.

Re:Headline: NASA WANTS MONEY (1)

Anonymous Coward | about 2 years ago | (#41733105)

For the horribly uniformed:

NASA, is not a waste of $, in fact for every $ we spend on NASA, the economy gets $8 back. (not true for other Govt programs, some have some return, but nothing like NASA)
http://www.freakonomics.com/2008/01/11/is-space-exploration-worth-the-cost-a-freakonomics-quorum/

  “Economic, scientific and technological returns of space exploration have far exceeded the investment. Royalties on NASA patents and licenses currently go directly to the U.S. Treasury, not back to NASA.”

Re:Headline: NASA WANTS MONEY (1)

Anonymous Coward | about 2 years ago | (#41728581)

The amount of money we budget for defense spending for one year is more than NASA's budget since it's existed. It's money well spent.

Re:Headline: NASA WANTS MONEY (1)

SilentStaid (1474575) | about 2 years ago | (#41728765)

Is that actually true? I'd love to see a citation on that. It would be incredible if it was. My Google-Fu is weak today, apparently.

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41728885)

If you're thinking about it in terms of a satellite coming down, plucking up an accident victim, and dropping them off at a hospital before returning to orbit, no.

If you're thinking about it in terms of weather tracking, wildfire management, military intelligence, etc. Then yes.

Re:Headline: NASA WANTS MONEY (5, Informative)

SilentStaid (1474575) | about 2 years ago | (#41728937)

I hate to reply to myself, but one shot of caffeine later and the results are in:

Projected budget for FY12 for NASA: $17,770m, or 0.48% of the total Fed budget.
Projected budget for FY12 for the Military: $1,030,000m – $1,415,000m, or potentially 33% of the Fed budget.

So now the question is, what has NASA spent historically? Well, if you normalize dollar amounts over the course of NASA's almost 60 years the grand total is 870,709m or a healthy 160,000m dollars below the lowest estimated cost for the military this year...

I don't want to live on this planet anymore.

Sources: http://en.wikipedia.org/wiki/Budget_of_NASA [wikipedia.org] ; http://en.wikipedia.org/wiki/Military_budget_of_the_United_States [wikipedia.org]

Re:Headline: NASA WANTS MONEY (5, Funny)

GodfatherofSoul (174979) | about 2 years ago | (#41729045)

I don't want to live on this planet anymore.

Good News! We've got the firepower to make that happen since we haven't been wasting money on satellites!

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41729527)

Sir, I literally laughed outloud. I wish I had a mod point for you.

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41729631)

Be sure to give us the address of whatever planet you move to so we can come crush your badly funded military and reap all the benefits of your peaceful space program.

Re:Headline: NASA WANTS MONEY (0)

Anonymous Coward | about 2 years ago | (#41731011)

"We should seek by all means in our power to avoid war, by analysing possible causes, by trying to remove them, by discussion in a spirit of collaboration and good will. I cannot believe that such a programme would be rejected by the people of this country, even if it does mean the establishment of personal contact with the dictators."

Neville Chamberlain - 1938

Re:Headline: NASA WANTS MONEY (1)

mikael (484) | about 2 years ago | (#41732861)

USA defence budget for 2011 = $708 - $695.7 billion (http://www.huffingtonpost.com/2012/08/06/defense-spending-fact-of-the-day_n_1746685.html, http://www.defense.gov/releases/release.aspx?releaseid=13281 [defense.gov] )

USA defence budget for 2007 = $740 billion (http://www.globalsecurity.org/military/world/spending.htm)

NASA budget has varied between $33.514 billion in 1968 to $17 billion these days (http://en.wikipedia.org/wiki/Budget_of_NASA)

One years USA defence spending exceeds the entire NASA budget for 50 years.

Re:Headline: NASA WANTS MONEY (1)

gmuslera (3436) | about 2 years ago | (#41729593)

USA military expenses are some orders above and beyond NASA ones, and directly or indirectly kill more people than the lack of healthcare. While it don' t makes invalid your argument, is like complaining for an ant in a room filled with elephants.

Re:Headline: NASA WANTS MONEY (1)

Gripp (1969738) | about 2 years ago | (#41731339)

Our GPS and intelligence satellites have saved VASTLY more lives than the difference in health care (e.g. per dollar spent)
Keep in mind that NASA runs something like 20 billion, while healthcare is in the trillions. It would accomplish next to nothing.
More over, the money they spend PAYS AMERICANS.. so the money isn't really lost. It's put back into the economy. So really, go pick up some critical thinking skills before the next election, for all of us; please.

Also, on the extreme side of things: in the long run one thing or another will REQUIRE humanity to GTFO this planet. So by following your advice we'd technically be increasing the potential to kill all of mankind, just to not even actually save anyone now.

Oh Yay (0)

kiriath (2670145) | about 2 years ago | (#41728277)

Wall-E

Re:Oh Yay (1)

tysonedwards (969693) | about 2 years ago | (#41728323)

You're telling me that our consumer driven, planned obsolescence culture has extended into space and that now those tree-huggers are trying to extend their reach too? What is this world coming to?

What about my car? (4, Funny)

yog (19073) | about 2 years ago | (#41728517)

Maybe if this is successful, Nasa can spin off the technology to earth-bound vehicles as well. I would love to have some robot wander by from time to time and refuel or service my car overnight! You could even have robotic landscapers and robotic Christmas decoration putter-uppers. Really, the possibilities are endless. And, of course, a commercial success with this would help pay for more space exploration.

Re:What about my car? (1)

kiriath (2670145) | about 2 years ago | (#41728879)

But then they would get smart, want rights, form an army. We'll eventually be forced to black out the sun due to their mystical use of solar energy. Which will lead to them enslaving the human race and utilizing our comatose bodies as batteries.

I should so write a book series about that...

Re:What about my car? (0)

Anonymous Coward | about 2 years ago | (#41730693)

Scientists are actively working on a test [technologyreview.com] for whether the universe is a simulation.

Re:Oh Yay (1)

GoodNewsJimDotCom (2244874) | about 2 years ago | (#41728601)

R5-2do

So...um... (4, Funny)

stillnotelf (1476907) | about 2 years ago | (#41728349)

What will refuel the refueling robots? Refueling-robot-refueling robots? Hopefully they're universal and can refuel each other, at which point we have a perpetual motion machine (as opposed to an infinite mass of fuel-hungry robots in geostationary orbit).

Re:So...um... (1)

Anonymous Coward | about 2 years ago | (#41728399)

The refueling robots could just drop out of orbit to Earth to be recovered and reused?

Re:So...um... (4, Informative)

Rich0 (548339) | about 2 years ago | (#41728413)

The refueling robots could just drop out of orbit to Earth to be recovered and reused?

That way they can only carry half as much fuel? It takes a lot fuel to get from transfer orbit to geostationary orbit, and just as much fuel to get back down. The energy to get to transfer orbit in the first place is a one-time expense, since atmospheric drag and gravity will get you back down from there.

Re:So...um... (1)

tomhath (637240) | about 2 years ago | (#41728603)

The energy to get to transfer orbit in the first place is a one-time expense, since atmospheric drag and gravity will get you back down from there

Care to explain how? In order to repair and refuel the robot must be in the same geostationary orbit as the satellite it's fixing. Read that carefully - geostationary orbit - it's not going to fall down.

Re:So...um... (1)

Dekker3D (989692) | about 2 years ago | (#41728707)

"Transfer orbit". Probably the kind of orbit where you transfer from atmosphere to "space" (as in, getting almost no drag from the atmosphere anymore). That's different from geostationary... and changing orbits takes a lot of fuel, that's simple.

Re:So...um... (1)

Yoda222 (943886) | about 2 years ago | (#41730119)

If the refuelling satellite is on GTO and the satellite is in GEO, the refuelling will not be very easy. Have you ever tried to refuel a running formula one with the spare tank on your bicycle ?

Re:So...um... (1)

Rich0 (548339) | about 2 years ago | (#41732215)

Yup, hence the whole point of my post. If you want it to come back down you need way more fuel, since you would have expended the energy to get into geostationary orbit and need to expend it again to come back down...

Re:So...um... (1)

S.O.B. (136083) | about 2 years ago | (#41730153)

"Transfer orbit". Probably the kind of orbit where you transfer from atmosphere to "space" (as in, getting almost no drag from the atmosphere anymore). That's different from geostationary... and changing to a higher orbit takes a lot of fuel, that's simple.

FTFY.

Changing to a lower orbit takes a lot less energy.

Re:So...um... (1)

Yoda222 (943886) | about 2 years ago | (#41730197)

Going from GTO to GEO or from GEO to GTO needs the same DeltaV (in fact -DeltaV) So if you have the same initial mass and the same thrusters, you need the same amount of fuel. (but if you do GTO to GEO to GTO, you don't have the same mass ;-) )

Re:So...um... (0)

Anonymous Coward | about 2 years ago | (#41732163)

Especially considering the fact that you are leaving a bunch of fuel in GEO, apart from that which you burned to transfer.

Re:So...um... (1)

K. S. Kyosuke (729550) | about 2 years ago | (#41730195)

That's different from geostationary... and changing orbits takes a lot of fuel, that's simple.

Changing certain elements of the orbit, such as inclination, is very costly (unless the apogee is very high). Changing others, not so much. You can transfer between individual geostationary satellites at a fairly modest fuel cost, if you're willing to wait a little bit more. The machine could also employ electric engines, that would make the whole thing much more efficient. Geostationary satellites started using them some time ago anyway, to perform East-West station keeping, but I believe there are either plans or even working satellites to use electrical engines for North-South station keeping as well. If the fuel is compatible (Xe, typically), an electrically-driven repair robot satellite could just pump some of its fuel to the target satellites and be done with it.

Re:So...um... (1)

Rich0 (548339) | about 2 years ago | (#41732193)

Read my whole post carefully.

To get to geostationary orbit there are two energy expenditures. One is from ground to geostationary transfer orbit. The other is from transfer orbit to geostationary orbit.

To get back there is really just one energy expenditure - from geostationary orbit to transfer orbit. The bottom of transfer orbit would be far enough in the atmosphere that drag would do the rest - you don't need to re-circularize it with propellant.

However, no question that you'll need a ton of fuel just to get back to a transfer orbit.

Re:So...um... (3, Informative)

Baloroth (2370816) | about 2 years ago | (#41728645)

and just as much fuel to get back down.

Provided the mass stays the same. Can you guess why a tanker-satellite might have significantly less mass after it's re-fueled a bunch of other satellites? (hint: it's because it isn't carrying all that fuel any more).

Re:So...um... (1)

Rich0 (548339) | about 2 years ago | (#41732251)

Fair enough, but I'm sure it will still take a fair bit. If the tanker sat is designed to be simple I doubt it would be worth it. Plus now you have to contend with re-entry - that's a lot of extra mass.

Re:So...um... (1)

S.O.B. (136083) | about 2 years ago | (#41730115)

The refueling robots could just drop out of orbit to Earth to be recovered and reused?

That way they can only carry half as much fuel? It takes a lot fuel to get from transfer orbit to geostationary orbit, and just as much fuel to get back down. The energy to get to transfer orbit in the first place is a one-time expense, since atmospheric drag and gravity will get you back down from there.

The reason it takes fuel to get to geostationary orbit is because you're fighting gravity. Why would you need to use the same amount of fuel to come back down when gravity is helping you along?

As someone else pointed out, the refueling robot is now a lot lighter having just refueled a satellite so even less fuel is required. My guess is all you have to do is aim the refueling robot at it's reentry window, give it a nudge and let gravity do the rest.

Re:So...um... (4, Informative)

Patch86 (1465427) | about 2 years ago | (#41730513)

That's not how orbital mechanics work.

Orbit is basically (in really inaccurate terms which someone will undoubtedly shoot me down on) where you're travelling sideways fast enough that, although you're falling towards the Earth, you keep missing. It's like when you throw a ball in a straight line, and it travels along and curves down towards the ground. Imagine throwing the ball so hard that the curve downward takes it over the horizon. This trick works because atmospheric drag is so little in orbit, once the object has achieved a high enough speed that it keeps "missing" the Earth, it retains that speed for a good long time.

So, in order to get up to geo-stationary orbit, you basically have to add a huge amount of speed to your satellite by burning lots of fuel. Once it's up to speed and stops burning its engines, it stays up to speed.

If you want it to come down again, you need to cause it to lose speed. In order to do that, you need to burn a rocket engine in the opposite direction to slow it down. It takes the same amount of fuel to reduce speed by 1 km/h as it does to gain speed by 1km/h. So you need to burn almost* the same amount of fuel to get back down as you do to get up there.

(* "Almost" because you only need to lose altitude to the point where atmospheric drag picks up, and then you start to lose speed "naturally")

Re:So...um... (1)

Rich0 (548339) | about 2 years ago | (#41732301)

Yup. Granted, others have pointed out that mass will be lower so the amount of fuel required to change velocity will be lower. However, it will still be a significant amount of fuel to get back down. More if the whole thing needs a fancy re-entry shield and the required additional structural strength.

Re:So...um... (1)

Coisiche (2000870) | about 2 years ago | (#41728437)

A-ha! A perfect cover story for the X-37B. Expect to read it in a press release soon.

Bonkers (3, Interesting)

Anonymous Coward | about 2 years ago | (#41728527)

The whole "let's re-use spacecrafts" has been conclusively demonstrated to be Economic Nuts by the Space Shuttle program (1kg lifted by the shuttle is ten times more expensive than 1kg lifted by a throw-away rocket) . I have the definite feeling NASA wants to prove this once again, just in a different way.

But maybe we should read this message metaphorically ;-)

Re:Bonkers (1)

K. S. Kyosuke (729550) | about 2 years ago | (#41730051)

The whole "let's re-use spacecrafts" has been conclusively demonstrated to be Economic Nuts by the Space Shuttle program (1kg lifted by the shuttle is ten times more expensive than 1kg lifted by a throw-away rocket)

No, the Space Shuttle program is just anecdotal evidence. Anecdotal counter-evidence would be fixing and maintaining the Hubble Space Telescope, as opposed to building a launching a new one. But don't allow facts get in the way of your thoughts, that's never good.

Re:Bonkers (0)

Anonymous Coward | about 2 years ago | (#41732503)

Anecdotal counter-evidence would be fixing and maintaining the Hubble Space Telescope, as opposed to building a launching a new one.

Except building and launching a new one every three years would almost certainly have been cheaper, so long as it was launched on a cheaper, expendable rocket and not the shuttle.

Re:Bonkers (0)

Anonymous Coward | about 2 years ago | (#41732695)

Actually, the Hubble is also anecdotal evidence against reusability largely because it relied on the shuttle. Launching the shuttle to service Hubble probably cost more than building and launching another Hubble would have. The military was "mass" manufacturing largely the same design as a spy satellite and lobbing them into space on expendable rockets. That's why there are now two "free surplus Hubbles" available if NASA can find the money to refurbish and launch them. Once you set up a production run, the marginal cost of a satellite goes way down and the launches are a third the cost of a shuttle launch.

Reusability is, in my opinion, still a worthy goal and a requirement if we are ever to have routine human access to space.

Re:Bonkers (1)

Anonymous Coward | about 2 years ago | (#41730055)

I'm not sure why this is modded up. The shuttle was an expensive boondoggle, but that was because the flight rate was low and fixed costs were high. A single shuttle flight cost around $200,000,000 and put about the same amount of mass into space as a Saturn V did at 10x the cost, most of it just happened to be wings and fuselage. What raised the cost of a shuttle flight to over a billion dollars a time were the enormous fixed costs of maintaining the required infrastructure, which would have applied just as much to an expendable launcher using the same facilities at the same flight rate.

People would be saying reusable aircraft make no sense if we spent billions of dollars a year supporting airports which only flew aircraft four times a year. And given the fixed costs of supporting refueling spacecraft in orbit would be approximately zero, those issues do not apply here.

Re:Bonkers (1)

They'reComingToTakeM (1091657) | about 2 years ago | (#41730093)

Obligatory ID4 quote:-

Julius Levinson: "You don't actually think they spend $20,000 on a hammer, $30,000 on a toilet seat, do you? "

Re:Bonkers (1)

sjames (1099) | about 2 years ago | (#41730793)

The Space Shuttle was a first attempt. It's no surprise it didn't work exactly as planned.

For example, if we were to design it again now, it would have an expendable ablative heat shield rather than the tiles.

Re:So...um... (1)

sjames (1099) | about 2 years ago | (#41730669)

I would think an expendable tanker would be a better option. Put it in LEO, the refuelers fill up from it and go about their business.

Re:So...um... (2)

Impy the Impiuos Imp (442658) | about 2 years ago | (#41728475)

Yes, the space refueling robots can refuel each other, too. Haven't you ever played Total Annihilation????

Re:So...um... (1)

schlachter (862210) | about 2 years ago | (#41728479)

Perhaps a single refueling robot that can top off several satellites and reposition a few more is cost effective enough to justify a one-time refueling satellite? Long term, we could imagine that such robots will be refueled via space based resources (asteroid mining, etc).

Re:So...um... (1)

khallow (566160) | about 2 years ago | (#41728513)

Well, we could launch more propellant from Earth. Launch it, the robot tanks up, and keeps going. One could even do major orbit change burns at this time using excess propellant.

Re:So...um... (3, Informative)

Baloroth (2370816) | about 2 years ago | (#41728619)

What will refuel the refueling robots? Refueling-robot-refueling robots?

Pretty sure you're just being snarky, but the principle is the same as tanker aircraft. A satellite dedicated to carrying fuel can carry vastly more of it than a satellite dedicated to communications. And after it is done, the mass of the fuel-carrying robot is significantly less than it was when placed into orbit, so the cost of de-orbiting is much much less than the cost of orbiting it in the first place (since the vast majority of the mass of the satellite is now gone).

Re:So...um... (1)

stillnotelf (1476907) | about 2 years ago | (#41728673)

Oh, I was definitely being snarky (perpetual motion? infinite mass?). I understand the aerial refueling idea - a certain Mr. Clancy always wrote lovingly of the KC-135. Sometimes figuratively, and once more literally when he called it something like "airplanes having sex". In general I'm in favor of any idea that will reduce the orbital debris problem.

Re:So...um... (1)

mk1004 (2488060) | about 2 years ago | (#41729275)

If it doesn't matter how long you take to get from LEO to geosync and back again, then maybe an ion-drive using solar panels for power. That maximizes the payload that gets to geosynchronous orbit, and you resupply the repair satellite periodically while it's in LEO. One issue I'm concerned with is how standardized any available connections are on the satellites to refuel them. But the repair satellite could be made versatile enough to bring satellites to LEO for repair/refueling. Perhaps someone on the ISS could do EVAs to repair them, and unmanned resupply ships would bring up parts and fuel. The repair satellite could also be used as a tug to take new satellites from LEO to geosync, saving weight on the launch vehicle--no need for a one-use booster to take the satellite from LEO to geosync.

Re:So...um... (1)

zippthorne (748122) | about 2 years ago | (#41732683)

And if the time really doesn't matter, then you use a flashlight drive or solar sail....

Re:So...um... (1)

mk1004 (2488060) | about 2 years ago | (#41734127)

OK, the SMART-1 http://en.wikipedia.org/wiki/SMART-1 [wikipedia.org] went from an initial orbital period of about 11 hours to 25 hours in about 147 days. This was achieved running the ion drive for 1/3 to 1/2 of the orbit, since they wanted a highly elliptical orbit. LEO for the repair/resupply satellite would start with a more circular orbit and a period of about 90 minutes. If you run the ion drive for most of the orbit, I'd guess that would roughly balance out the lower starting point. Only 22% of the weight was propellent. Of course, you'd need more propellent to drop back down to LEO afterwards. Overall, ion drives are suppose to be about 800% more efficient than chemical rockets.

Some of the new geosync satellites are using ion drives to get to synchronous orbit, and those take several months to do so. NASA has done some research on a reusable ion-drive booster: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19790009727_1979009727.pdf [nasa.gov]

One issue is that because the satellite will spend a fair amount of time in the Van Allen belt, the solar cells will be degraded over time and will need to be repaired or replaced. The ion drive itself experiences erosion of certain components that require periodic replacement.

Re:So...um... (1)

Belial6 (794905) | about 2 years ago | (#41729301)

Hopefully, the refueling robot isn't being launched over and over. Much better would be to put a spacecraft up there that can pull fuel from a big dumb lumbering tanker and deliver it to the specific satellites. This way, the craft being launched full of fuel can carry more fuel/parts/whatever, and doesn't need to carry all of the equipment for performing the more detailed work.

Re:So...um... (0)

Anonymous Coward | about 2 years ago | (#41730291)

If they're just carrying fuel, they can potentially use ion engines or some other means of changing orbit which is much more efficient than chemical rockets.

China needs more rocket technology! (1)

For a Free Internet (1594621) | about 2 years ago | (#41728361)

Just in case it has to knock those imperialist war spying machines out of the sky! The working class internationally must defend the Chinese bureaucratically deformed workers state! Smash imperialism with international socialist revolution! Dalai Lama kiss my ass!

How About Calling It RRR (2)

LifesABeach (234436) | about 2 years ago | (#41728423)

Refuel, Reposition, and Repair

With apologies to AAA.

Re:How About Calling It RRR (1)

bughunter (10093) | about 2 years ago | (#41732139)

I was thinking something very similar: Robotic Refueling Rendezvous (RRR).

Of course, it would have to launch on Talk Like a Pirate Day.

Arr, arr, arr!

Civvie version of X37-B (2)

Anonymous Coward | about 2 years ago | (#41728447)

All NASA has to do is ask the Air Force if they can get a civvie version of the X-37B.

Yeah they keep it missions "secret" but this pretty much fits the only reason for having an autonomous space-truck with a robotic arm and cargo bay. Afterall, they're not going to be getting a full-sized replacement for the Shuttle anytime soon, so this is the next best thing.

Nope (0)

Anonymous Coward | about 2 years ago | (#41728555)

Everything that can re-enter the atmosphere is incredibly expensive and can only be justified with some "super-duper enemy-strategic stallite snatch" "value". Or maybe doing some exotic research on the effects of space (residual atmosphere, van allen belt etc) onto advanced sensors.

Otherwise, just shoot up the sat and then either let it circle forever or let it burn up (if low-flying). That is by far cheapest.

Re:Civvie version of X37-B (3, Informative)

rossdee (243626) | about 2 years ago | (#41729009)

I don't think the X37-B can reach geostationary orbit

Talk about Scope Creep (4, Interesting)

Rich0 (548339) | about 2 years ago | (#41728509)

I could almost see there being some value in refuel. Maybe also in reposition if a big change is involved (but why would you need to move it anyway?). Take a few pictures of it if you want, since that is fairly cheap.

However, when you start getting into repair you're talking about a massive increase in cost and decrease in reusability of the refueling ship.

And if you don't do repair, then you need to design the satellites to have components that last for decades but a fuel supply which lasts much less - why not just launch it with a lifetime fuel load?

Repositioning only makes sense if it was unplanned and needs more propellant than could be carried by the satellite. If you dock a ship to it and use that to move the satellite, then you need enough fuel to reposition the combined mass of both. It would be smarter to just refuel it and let the satellite move itself.

Oh, and unless you're really patient, moving from satellite to satellite takes a fair bit of fuel (a little nudge goes a long way if you're willing to wait, but with each orbit lasting a day it will be probably weeks between encounters if you don't want to do large burns).

I think that the only way private companies would sign up for this refueling service were if the cost of the service were basically subsidized on the backs of taxpayers. I could be wrong, and that would be wonderful, but this really seems like a solution looking for a product. Sometimes it really is cheaper to just make a new one.

Re:Talk about Scope Creep (2)

tomhath (637240) | about 2 years ago | (#41728699)

The satellites frequently reposition themselves, because no matter how accurate they are placed into orbit they drift a little. I can see having a tanker satellite up there that can help reposition one that wandered out of place and refuel it if the physics of docking with it are possible. Maybe even replace a solar panel once they standardize external parts and connections. The tanker would need a much stronger engine so using it to reposition would probably make sense in some circumstances.

Re:Talk about Scope Creep (4, Insightful)

thrich81 (1357561) | about 2 years ago | (#41728767)

You hit on my main concern in your last paragraph -- taxpayers subsidizing the owners of the geosynch satellites. If there is one space activity which private industry has figured out how to make a profit on it's geosynchronous satellites -- if refueling them is a great idea then the owners of the satellites can invest in developing the technology to do it. Let NASA spend its money going to Mars, etc.

Re:Talk about Scope Creep (0)

Anonymous Coward | about 2 years ago | (#41728893)

It would seem reasonable to think that NASA would charge money for the service and not do it out of the charity of their heart.

Re:Talk about Scope Creep (1)

eth1 (94901) | about 2 years ago | (#41733701)

You hit on my main concern in your last paragraph -- taxpayers subsidizing the owners of the geosynch satellites. If there is one space activity which private industry has figured out how to make a profit on it's geosynchronous satellites -- if refueling them is a great idea then the owners of the satellites can invest in developing the technology to do it. Let NASA spend its money going to Mars, etc.

Well, they could actually be trying to subsidize the refueling of government craft with corporate money, too, depending on how you look at it.

In any case, I'm curious how they plan to refuel a satellite that wasn't designed to be refueled in space. It's not like you can just unscrew the gas cap and stick a hose in. (maybe that's why "repair" is included in the mission parameters? Some amount of dis/re-assembly required?)

Re:Talk about Scope Creep (2)

Kjella (173770) | about 2 years ago | (#41729007)

However, when you start getting into repair you're talking about a massive increase in cost and decrease in reusability of the refueling ship.

It might not be Hubble-class replacement jobs we're talking about, it may be changing the windshield wipers but there's nobody to do it because it's 36000 km away from the nearest service station. Yes, each repair job will probably be a custom fit but I imagine this refuel/repair course is laid out before it even launches, I doubt it'll be orbiting up there waiting for customers.

And if you don't do repair, then you need to design the satellites to have components that last for decades but a fuel supply which lasts much less - why not just launch it with a lifetime fuel load?

Weight and size constraints? Big rockets costs big money, if you can get away with a smaller launch vehicle and a top up in orbit maybe it will be cheaper. Personally I'm thinking more about big military satellites in low earth orbit that may need this much more often than GEO satellites. It could also put us in a position to do missions bigger than our current launch capability - which may be a very neat trick for say a Mars mission. I doubt we'll be building more Saturn Vs.

Oh, and unless you're really patient, moving from satellite to satellite takes a fair bit of fuel (a little nudge goes a long way if you're willing to wait, but with each orbit lasting a day it will be probably weeks between encounters if you don't want to do large burns).

So what if it does? They know when the satellites run out, it's not like they one day look at the dashboard and discover they're in the red and need a top up right now. Say a year long mission to top up 10 satellites sound like a perfectly reasonable duration for me. I must admit, I don't see huge wins for this, but it's skills that will only become more valuable the more satellites and things we put up there.

Re:Talk about Scope Creep (1)

Rich0 (548339) | about 2 years ago | (#41734023)

You might have hit on something with the military bit. They stick some giant billion dollar mirror in space and just need some fuel to keep it up. Might let them do more maneuvering to put it where they want it when they want it there, and make it harder to keep track of.

Re:Talk about Scope Creep (0)

Anonymous Coward | about 2 years ago | (#41729179)

I would think the repair thing would not be for older satellites, but an option to consider, and possibly not use still, on newer satellites. A satellite could be designed so that some of its components are much easier to replace remotely. It becomes a matter of minimizing costs then. Maybe it is cheaper to plan on replacing a component that has a 1% failure chance than it is to add a redundant system or to lower the failure rate. In other cases it might be cheaper to add a copy of the component or build it better.

Re:Talk about Scope Creep (1)

Jammer6502 (1430197) | about 2 years ago | (#41731517)

Refuel and reposition will probably not need to be run at the same time. I imagine, as others have, the refuel capability may be difficult and will have to be designed into the satellite in the first place. For sats that need to be repositioned but cannot be refueled this robot could give them a boost, thereby saving it some much needed fuel for later maneuvers. (Say the robot was passing a sat without the capability to be refueled on its way to another customer, owner of the robot can offer owner of the sat a boost for some cost, then move on). I think the real use for this technology will be realized if we are ever able to park a icy asteroid in orbit, then fuel is already up there and just needs to be distributed. This is just preparing a tech for a later use.

Re:Talk about Scope Creep (1)

khallow (566160) | about 2 years ago | (#41732445)

Maybe also in reposition if a big change is involved (but why would you need to move it anyway?).

I'll answer this one since there are some relatively straightforward answers to that.

There are two big reasons. First, satellites don't always end up where you want them. For example, the recent SpaceX launch put its payload in an incorrect orbit that'll require some burns by the satellite to get into the desired orbit. The more onboard propellant you use, the shorter the lifespan of the satellite.

Second, there's the closely related problem of tight launch windows which is especially a problem when filling in a constellation of satellites with only a few gaps in its geometry or trying to hit a launch window for an orbit with a high inclination (angle of the orbit with respect to the plane of the Earth's equator). A repositioning system might give one a means to put a satellite into the desired orbit (though the repositioning satellite might have to boost itself back into its old orbit.

What about Retiring? (2)

T_Tauri (883646) | about 2 years ago | (#41728571)

Surely one of the main jobs this kind of program would encounter is retiring any satellite that it finds it cannot repair/refuel? Effectively just re-positioning into an orbit that intersects the atmosphere but given the problems of space junk I would have thought they would want to highlight this potential benefit especially as it increases the "R" count to 6.

Re:What about Retiring? (1)

steelyeyedmissileman (1657583) | about 2 years ago | (#41728647)

I was going to suggest "Reclaim" or "Recycle".

Re:What about Retiring? (1)

Dekker3D (989692) | about 2 years ago | (#41728727)

How about R-slamdunkintoatmosphericdeath?

Re:What about Retiring? (1)

gmuslera (3436) | about 2 years ago | (#41729797)

Retiring is a necessary thing, but not in the same category. Taking out old/dead/broken satellites that could be a risk in a near/middle term. But what about the non broken ones? nuke them and send up a replacement or try to refuel them? In the middle term could be cheaper to try to keep them up and running than somewhat destroying them.

Kind of Late in the Game (1)

FudRucker (866063) | about 2 years ago | (#41728599)

they should have thought of that 30 years ago

Re:Kind of Late in the Game (0)

Anonymous Coward | about 2 years ago | (#41729097)

they should have thought of that 30 years ago

They did: the NRO's KH-12 recce sats have orbital refueling capability. It was one of the use-cases for the Shuttle Orbiter to top them up.

That's one reason why pads were built to loft STS from Vandenburg AFB in California.

EMDrive - no need to refuel (0)

uncle slacky (1125953) | about 2 years ago | (#41728611)

Fit out the sats with an electric drive instead, like this: http://emdrive.com/ [emdrive.com]

Doesn't seem economic (1)

rossdee (243626) | about 2 years ago | (#41729065)

By the time a satellite in geostationary orbit needs refueling the technology will have advanced a lot, so why not just repelace it with a newer satellite that has more bandwidth and capabilities.. It might make sense for speciallised things like space telescopes, but not for general comunication / TV satellites.

Refinery (1)

Curunir_wolf (588405) | about 2 years ago | (#41729127)

The next step is to build a refinery right there in orbit, and mine some asteroids for raw materials. Or some Jupiter moons, even better, since they are loaded with hydrocarbons. That is where the real savings would be, since you're not paying to blast all that fuel into space.

The orbit, itself (4, Interesting)

dpilot (134227) | about 2 years ago | (#41729199)

More likely, the most valuable thing up there is not the satellite, it's the position it's occupying. Once upon a time, we tried to keep 2 degrees of separation between geosync satellites - meaning that there were 180 "slots" where one could be placed, and obviously fewer than that that could service any one location. The separation keeps dropping, but that makes the need for stationkeeping more precise, probably calling for more fuel, etc.

So the best thing here is to keep those geosync slots in use, and not chewing up an empty slot with a dead or useless satellite. I'll have to agree with what someone else said - that de-orbit should be a published option, as well.

Personally, I believe the best option is a big, gravity-gradient-stabilized boom, with some serious solar panel capacity on the outer side, battery capacity to match, and standardized electrical and mechanical hookups. Then rather than sending up complete satellites, lease hookups on the boom, and just send up an electronics package. In this case, the "service satellite" carries the package up, anchors and connects it, and does initial checkout.

Re:The orbit, itself (2)

Clueless Moron (548336) | about 2 years ago | (#41731649)

So the best thing here is to keep those geosync slots in use, and not chewing up an empty slot with a dead or useless satellite. I'll have to agree with what someone else said - that de-orbit should be a published option, as well.

De-orbiting from geosync is way to expensive to be an option (too high delta-V). What they use instead is the "graveyard orbit". At the end of operational life, the satellite just does some final burns to raise its orbit by a few hundred km, where it is no longer geosynchronous but also out of the way of the geosync orbit. Satellites launched into geosync are required to have this capability.

Re:The orbit, itself (2)

dpilot (134227) | about 2 years ago | (#41732439)

How save is the graveyard orbit, really? It'll be even less likely to decay than geosync, but isn't it then a "fixed size trashcan?" At some point won't you start getting collisions, and some of the pieces might get enough delta-V to get in the way. Certainly the graveyard orbit is cheaper than de-orbit, but for the long run, have our repair satellite tow them out there and attach them to the junkyard. (The other dead satellites, all "tied" together.)

Robots get all the fun (1)

Chelloveck (14643) | about 2 years ago | (#41729261)

How come we let robots have all the fun? I'd sign up for a job as geosync satellite gas-station attendant in a heartbeat! Who wants to be a coddled planet-bound human? I'll welcome our robot overlords only if they let me in on a piece of the action.

Refeuling may not be a snap (1)

DadLeopard (1290796) | about 2 years ago | (#41730361)

Most, if not all, present day satellites do not have fuel tanks that are made to be refueled, a lot have tanks that aren't even accessible from the exterior. They are going to have to come up with some kind of a way to put a hole in a tank, that doesn't put metal shaving inside, and install a refueling port that is perfectly sealed to the tank for this to be able to work. Might have to wait for the next gen of satellites before starting this service. Though NASA being NASA, they have pulled off some amazing things in the past, duct tape and CO2 removal canisters comes to mind!

Re:Refeuling may not be a snap (1)

0123456 (636235) | about 2 years ago | (#41731051)

Hint: how do you think those tanks were filled on the ground?

I believe this is mainly intended for new satellites, but there has been talk about refueling old ones using existing ports.

who is the real customer? (0)

Anonymous Coward | about 2 years ago | (#41731023)

The most expensive satellites out there aren't civilian. The satellites with the most aggressive repositioning, and correlated fuel consumption, aren't civilian. The greatest dollar value of currently-useless satellites isn't civilian. The hardware and techniques developed in the open can be of value to all organizations with dead inventory out there. The results of this project has the potential to significantly save taxpayer money. NASA is perfect for this task. The results are generic, the project gives NASA something to do, NASA has experience with maintenance of already-lofted satellites, NASA can use the results itself when trying to revive old missions or when planning new ones, and NASA can become a resource yet again to others who have the budget and the need. Let's all hope NASA can progress and succeed. We'll then get even more bang for our bucks.

American Worker is Doomed (2)

SethJohnson (112166) | about 2 years ago | (#41731263)

First it was self-serve gas pumps. That relegated the station attendant to a cash register operator.

Then they implemented gas pumps with credit card readers. No need to interact with a human running a cash register. Fully automated fuel stations.

Now, we've got a huge new industry being invented, and they're not even including humans in any part of this transaction. No one to ask what grade of fuel to use. No one to check the condition of the wiper blades or upsell the satellite owner on a new air filter. Probably going to have NFC chips on the satellites so there's not even a credit card to swipe to charge the customers for the fuel.

I gotta get on the horn to my congressman today. This is going to be too efficient at the cost of jobs. We need to employ a human operator up there or else there is no hope of the unemployment rate dropping below 7%.

Seth
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