Slashdot Mirror
Space Tugboat to Refuel Satellites
Faeton sent in this article about a proposed space tugboat to refuel aging satellites. Looks like they're just going to bolt on some extra thrusters with a new fuel supply, guidance system, etc.
← Back to Stories (view on slashdot.org)
There goes any more chances for free tacos.
Need help treating your acne? Come here!
Now we won't have to keep replacing them, just keep refuling them. But wont the sattellites lose speed in docking?
If you don't vote, you don't matter, so don't waste your time telling me your opinion
The title calls this a "tugboat", but as far as I can see from the article, it is really just an extra fuel tank and set of rockets.
A real tugboat would be very cool indeed -- something which could grab a satellite, move it up back into the correct orbit, and then let go and move on to the next satellite -- but it looks like this is rather less so.
Tarsnap: Online backups for the truly paranoid
No, it's Sattelites, for the same reason Virii is incorrect (it's actually Viruses). Common mistake, though.
If the justification is weight-related launch costs, it may be about to be obsoleted by space elevators:
8 /2 0/1526242&mode=thread&tid=160
http://science.slashdot.org/article.pl?sid=02/0
I guess I'm just feeling nitpicky today. Other than that, this sounds like a great idea. Then again, I'm usually hyped about any space program. We've got less than 5 billion years or so to find a new home out there... :(
"To confine our attention to terrestrial matters would be to limit the human spirit." -Stephen Hawking
I thought that ion thrusters have proved themselves multiple times already for meneuvering in space. You can use the sun to power them and not have to worry about running out of liquid fuel.
What am I missing? Do they need *sudden* changes of direction? We are not talking about spy satellites.
Table-ized A.I.
I wonder if it's leaded or unleaded...
;)
Hey, if they use fuel that means they must be burning it off or something.
What about the environmental impact? How about greenhouse gases? Or do newer spacecraft use 'green' technologies. Save Space--keep space clean! And don't forget about..uhh...Solar System Warming!
We don't want to refuel old crappy satellites!
Please let them * burn * and then launch new generation satellites build on nanotechnology - they will be small and efficient!
... can't they just put newer, smaller, niftier satellites about ten klicks behind the first one in its orbital path?
Isn't all the money spent just getting there?
"Consider yourself a member of a virtual corporation with Mr. Torvalds as your Chief Executive Officer." - Linux Advocac
http://www.orbitalrecovery.com/faq.html
This article saddens me in this way: Technology such as this should be the natural, and MUNDANE, result of an "agressive space exploration policy". But its not, because the new machines we build for space are few and between. AND this lack of 'space ware' makes this FERRY newsworthy on /. .
I guess it just saddens me that we dont go out and make this solar system ours(humankinds).
but not Microsofts.
A Good Troll is better than a Bad Human.
This sounds remarkably like the first step in George William Herbert's "Phobos on the Cheap" paper, here.
The basic idea of the paper is that you could fund the development of these things by doing satellite maintenance and related things, then use one of them as the propulsion system for a trip to Mars orbit.
So I wonder if this is that project.
Back about a year ago, Taco Bell offered to give free tacos for a day if the Mir space station (then decomissioned) hit a particular target (floating in the ocean... Pacific Ocean, I think, but maybe Indian Ocean) when it fell out of space.
The joke was that if they strap boosters onto satellites, then one would assume that no satellites will fall, thus there's no chance for free tacos in the future. Of course, this really doesn't affect satellites that are decomissioned for other reasons, like obsolescence, nor was the Mir a satellite. Regardless, though, it's funny, if a bit inaccurate. :-)
120 character sigs suck. Make it 250.
Do you think this company is gonna charge the extra 40 cents per gallon for full-serve? If so, they better at least wash the windows and check the oil in the satellite.
Let A be the distance from the camera to the Earth.
Let B be the distance from the camera to the satellite.
The picture only gives you the ratio A/B, you can't "judge" the value of A alone.
It looks like they ARE using ion drives + solar panels. I wouldn't trust it, but it looks like they will be selling this as a fully insured package...
are real and fab. Too bad a lot of people cant actually imagine it. lol and yes. the savings would be extreme. I suppose my wished for space exploration wont come until we build one. damn.
A Good Troll is better than a Bad Human.
...and it's been tug'in at satelliti for years now.
This 'news' is so yesterday.
I can't wait until another article about self-tying shoe laces hits the airwaves.
Actually both plural forms of virus are correct. However the grammaatical correctness of each usage varies from sentence to sentence. If I cared at all and didn't have a psycho for an english teacher at college, I would know the rule to explain why... I just know that we went over that in our last class.
Erutangis ym si siht.
But the thing is... old satellites don't die. They just sit up there, cluttering up the orbital space. The GPS system, for example, expects to retire satellites at a regular rate into "parking orbits". In fact recently, as this article in Space Daily shows, it was discovered that the parking orbits chosen will degrade and pose a threat to the operating GPS satellites in 20 to 40 years. This is a long-term problem that is only getting worse.
Refueling satellites at least gives us the control of them needed to take them out of orbit if required.
Anna B
<lame joke>Now those space geeks can have a good tug!</lame joke>
Thanks Michael for that masturbatory exercise in moderation!! We all know that mod rampage was your work. What else can we expect from a fradulent Nazi who refuses to apologize to Seth Finkelstein?
Both of the articles mentioned that fuel is not the only problem, the rest of the satellite has degraded as well. So, why don't they come up with a good garbage collection method to periodically get rid of the old sattelites. This could also partially answer the problem that it's starting to be pretty crowded there in the orbit already.
I'm curious why they haven't started using something like this to remove old satellites. A remote controlled vehicle equipped with a mass delivery system (rail gun, propellent, hell it could even ram them) that would deliver enough force to knock the old satellites out of orbit and maybe on a vector towards the sun where they will be quietly taken apart into component atoms.
Any atronomists/physicists know what the gravitational pull of the earth is in orbit and how much force would be necessary to kick, say, a 2000 lb satellite to escape velocity?
This message brought to you by the Council of People Who Are Sick of Seeing More People.
Commercial television satellites have a lifespan of about 10-15 years, and more in an inclined orbit, (which, admittedly, is generally not used for DTH broadcast purposes, but can be if the inclination is small, say half a degree), and after 15 years, the technology is very outdated.
Imagine how useful it would be to re-fuel Astra 1A, a 16 transponder, KU band satellite, which is lower-powered than what is typical for DTH today, and which also has footprints which let the signals from some transponders spill over to countries well outside Europe, which some broadcasters don't appreciate very much - you can receive Astra 1A in parts of Latin America and Canada with a large dish, (about 20 foot).
Sorry, the only use for re-fueling satellites would be either after a failed launch, (not that useful, as you can always go inclined orbit to buy a bit of time until the insurance pays up, and most companies have in-orbit spares anyway), or for re-fueling weather satellites, which generally have a longer useful lifespan, but a lot of weather satellites are polar orbiters anyway, which don't need as much fuel as geostationary satellites.
How is this relevant, cogent, on-topic remark a troll?
I mean poor guy, he goes through some trouble for people who don't understand the reference, you know, maybe the rest of the planet where the ad didn't run, and he gets blasted.
Mods on crack, moderation is broken, etc...
I have read stories that such space tugs might already be in service in the "black world". They are being used by the US Gov't. to refuel / restation spy satellites.
It seems to me that there's a lot of hardware in orbit and that our modern complex society is dependent on this hardware. We also have a permanent space station up there (Alpha or ISS or whatever it's called). What say we use Alpha as a base for repairing and upgrading satellites as well as cleaning up orbital debris? What it would need is a space craft, kind of a tow truck in space. A couple of astronauts could take this tow truck to a satellite and reposition its orbit and make repairs. It would always be in space so it would be cheaper than having to send the shuttle up every time you want to repair a satellite. And it could find space junk and send it to burn in earth's atmosphere. This could be a real commercial role for Alpha. Combine this with tourism and Alpha might actually be a viable commercial entity.
The Moore-Murphy Law: The number of things that will go wrong will double every 2 years.
This is grabbing the hammer by the head, not the handle.
The problem is the total cost of launching a satellite - most of which is the cost of boosting it into orbit. To correct that, you don't need tugboats or shuttles, you need cheap lift systems.
You need to make the cost of putting a bird up low enough that you can plan on a controlled deorbit at end-of-life. Right now, the bird's owner will squeeze every last second of use out of the bird because it is so damn expensive. So they won't plan to save the last N kilos of fuel to deorbit it - that fuel translates into another year of operation.
The problem of boosting a bird into orbit can be split into three parts: initial lift, orbital insertion, and orbital circularization.
For initial lift, you just need a rocket that gets about 90% of the work done. If it gets 85% done, or 95% done, you can correct that in the next phase. As a result you don't need a complicated first stage. What I suggest is a rocket made out of a renewable resource for the casing, coupled with a simple propellant.
That's right, I am suggesting a big Estes rocket. A rocket with a casing made of paper, and solid fuel. A rocket that can set on the shelf for months before use, rather than a liquid fuel rocket that requires constant maintainance before launch. A rocket that is cheap enough to throw away - remember that every kilo you add to the rocket to be able to reuse it is over ten kilos of fuel, or a kilo of payload GONE. I call this the BPR - Big Paper Rocket concept.
For the second part, orbital insertion, you need a rocket that is controllable so you can make up the last 5-15% of the boost. Again, use a cheap system - solid fuel, liquid oxidizer. You throttle the rocket by controlling the oxidizer feed, but the fuel is solid. This has many of the advantages of the BPR - longer shelf life, simpler to make.
The last part, orbital circularization, requires a light motor - it's staying up with the bird, so we need to shave kilos. This is where a high specific impulse system like ion drive or liquid fuel is worth its mass in gold, quite literally.
Make the system cheap enough that you can launch a bird for less than a couple of million dollars, and the owners will not have a problem with deorbiting a bird before it is completely dry.
This way, you avoid having old birds with less than state-of-the-art systems cluttering the sky, taking places that a new craft could do twice the work in. This way, you avoid complex docking manuevers. This way, you bring the cost of getting stuff into space down where it is USEFUL to have a space station. This way you pave the way for Moon and beyond.
OK, that's my opinion. Pick it apart. Or, if you think I'm on to something, start beating on the Planetary Society, the National Space Society, vulture capitalists, NASA, and your congressmutants to make it happen.
www.eFax.com are spammers
When I studied satellite communications in grad school, the comment was always that the life span was to long on most communications satellites, not to short. We were shown graph after graph that illustrated that by the time the damn things were half way through their life cycle, a better model was available that handled a lot more traffic, better quality, half the size/price, or whatever. So you had a precious GEO slot taken up by a bird that was obsolete, while your competitor has a new one about to launch.
These things probably only have two useful applicaitons, orbital repair (not repair in orbit, but of the orbit), and de orbiting something to salvage the GEO slot. Not to say that the technology isn't great on its own merits.
Unfortunately, you can only refuel one satellite per launch of the space tugboat. Then you have to destroy it or end up with billions of space tugboats.
Check out the DARPA project for more info. Do a Google search on "orbital express" for other links and news.
~afniv
"Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"
Richard von Weizs
One of the first applications of the Shuttle back in the 70s/80s was that it would carry a SpaceTug to retrieve satellites from orbits higher than the shuttle to travel.
Does anyone know if Challenger had an impact on why it's taken so long to return to this, or was this one of those "oh YEAH, we promised this to Congress back in 1978" deals?
Mod Karma -1: I sed bad wurds. If I cep my mouf shut, I wud be at riyses.
re-fueling weather satellites, which generally have a longer useful lifespan, but a lot of weather satellites are polar orbiters anyway, which don't need as much fuel as geostationary satellites.
Just a couple of points..
Weather satellites are mostly geosynchronous as they feed large area pictures regularly back. (EG METEOSAT Series) The importance in most weather models is the temporal resolution (how quickly you get updates) rather than the spatial resolution. As long as you can see the weather systems you're fine, so this is in the order of kilometres per pixel.
On the other hand Earth Observation satellites (ERS1/2, LANDSAT, SPOT) are in polar orbits because the 'surveying' and environmental monitoring tasks they are used for require a high spatial resolution to see smaller features, with pixels in the order of metres. The trade off is in temporal resolution as it could be many days before the craft repeats the same ground track. (Here SPOT has the advantage as it has steerable instruments)
The unusual platform is the NOAA series of satelittes - the AVHRR instrument on these has a resolution of ~1km, but it is a polar orbiter. Interestingly it broadcasts freely so if you have the kit and the software you get the images. Over here in the UK on a good pass we can see Alaska/New York. Interestingly this provides an image that is good for weather use (as there is a good pass from one of the craft every few hours)but the resolution can be usefully used for Earth Observation use as well (Guess what my thesis used...)
The limit on the lifespan of most observing craft, as opposed to broadcast craft, is the size of the coolant tank. Thermodynamic principles mean that when observing temperatures and in the IR (where there are good windows in the atmosphere absorbtion) the sensor must be colder than the object, otherwise you can't tell what part of the signal is from the object, and which is from the sensor itself. Most craft use liquid hydrogen filled dewars and the coolant runs out usually about 3-4 years after launch.
Fuel in polar orbitors is used to change orbits during the lifespan of the craft (may spend first year doing low level hi-res passes, then boost out in the next few years). At altitudes of 200-300km they also suffer from atmospheric drag and occasionally need to use a small boost to maintain orbit.
When the fuel in this sort of craft becomes below a certain margin, they are usually brought into the atmosphere in a controlled fashion.
Geosynchronous craft ( almost all broadcast craft and weather craft ) fly at an altitude of 38400km (from memory - don't shoot) where for all intents and purposes they maintain the same position over the Earths surface. However its not perfect and they wobble, so fuel is used to correct the orbit and stay within the 2 degree internationally allocated slot. Also if, like Astra, you have several in the same slot you need to stack them at different orbits, and that takes fuel because they are in non-ideal orbits, and you have to keep them all lined up for those fixed dishes!
When the fuel in this sort of craft runs below a certain value they are boosted clear and, being outside the geosynchronous 'event horizon' they drift clear and off into space. No-one wants a rogue fuel-less satellite in this sort of orbit, so internationally the various radio communication agencies are fairly hot on making sure you play by the rules.
In general terms I would expect polar orbiters to use more fuel due to the atmospheric drag. I'm not counting here the fuel used to deliver the craft to its orbit, which is clearly much higher in a geosynchronous craft.
The worst thing that can happen to a broadcast satellite is for its delivery engine/system to fail - then you have a very expensive satellite, probably destined for one of the precious geosynchronous slots, parked in a polar orbit. If you can get a secondary system to it, and control it on its manoevering engines/systems then you get a second chance.
The big problem with space debris is the stuff thats already there, most operational satellites now have thier disposal already planned.
It looks the moderators left their brains at home this morning, so let me be the next guy to blow his karma in a desperate plea to the moderators to mod this guy up. He's not a troll at all. If you'd just read what he wrote (as well as the grandfather post) you will understand that.
Oh well, it's no use. Nobody will read this message.
If tits were wings it'd be flying around.
Well, I did. Sorry I don't moderate. Also feel sorry for the guy who "joked" and the people who went out of their way to explain the situation. Ah well, it's a thankless world.
Oh well, it's no use. Nobody will read this message.
/.'s loss, if somebody doesn't chuckle, isn't my fault, I tried my best. :-D
Well, I did. Sorry I don't moderate. Also feel sorry for the guy who "joked" and the people who went out of their way to explain the situation. Ah well, it's a thankless world.
Need help treating your acne? Come here!
A couple of years ago they would have had money thrown at them just because the have "powered by php" and "powered by MySQL" on their homepage and they're running an Apache webserver. Everyone would have assumed that they were open source friendly and just thrown their money at them. Now people are actually looking at the technology, isn't it wonderful!!!
:-)
However, it is cool that they are running open source software for their presence. I wonder if the on-board computers are running Linux or *BSD
I have no sig, does anyone have one to spare?
And everyone knows that tethers tug!
Read about tethers here.
**>>BELCH
about parent: it didnt seem offtopic when i wrote it. i was responding to an accusation that my original comment should not have included microsoft.
A Good Troll is better than a Bad Human.
The thing you have to think about is that even a misguided stray fleck of paint can potentially obliterate another satellite on impact. The growing amount of obital material also increases the potential for destructively colliding objects in orbit. Such a chain reaction which could effectively create a wall of space debris, preventing safe and economical space flights for the foreseeable future. It's just like the old analogy of dropping a penny off a 10 story building, except in this case you don't have air resistance to limit the velocities involved. In otherwords, moving another satellite into any new vector is necesarily a very delicate precision operation.
-Guanno
Have you ever seen what happens when you shoot an apple with a rifle? Y'know, how it flies apart into lots of fast-moving chunks? Well, the same would most likely happen to a satellite if you hit it with a railgun/mass driver round (or a missile, for that matter!). Somehow vaporizing it (with a laser or particle beam) might work better, but then you'd get a dense cloud of little dinky metal dust, and that could hurt too.
I'd say strapping an ion motor to it, and flying it to the moon would work better.
Okay. Hindsight is 20-20. But clearly future satellites should have the facility to get electricity from an external source.