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DARPA Aims To Reuse Space Junk

Soulskill posted more than 2 years ago | from the cannibal-satellites-dueling-for-survival dept.

ISS 67

CowboyRobot writes "Space junk has increased to the point where pieces of it are colliding and breaking into smaller pieces. The problem is now so bad that NASA has had to modify the design of satellites to protect them from flying debris. The Defense Advanced Research Projects Agency (DARPA) wants to turn disabled satellites and their components, including antennas and solar arrays, into functioning systems. They are hosting a conference on June 26 to explore how to build 'refurbished' satellites from already-orbiting material for less than what it would cost to build them from scratch and launch them from the surface of the Earth."

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Flying magnets (2, Funny)

Anonymous Coward | more than 2 years ago | (#39824225)

Flying magnets?

Re:Flying magnets (1)

icebike (68054) | more than 2 years ago | (#39825769)

Aluminum magnets! Titanium magnets!

Yeah, that will work.

Re:Flying magnets (2)

PaulBu (473180) | more than 2 years ago | (#39826287)

Sure that would work!

Make a coil of either metal, cool it down to 0.4K (Ti) or 1.1K (Al, which is probably what you would use), apply some current -- here is your superconducting magnet, sucking in Iron, Chrome, Nickel, etc... -- unfortunately, not Al or Ti, which satellites are usually made of... ;-(

While I am at that, can I suggest that new-fangled mid-80s thing, called hight-Tc superconductor? :-)

Paul B.

Re:Flying magnets (0)

Anonymous Coward | more than 2 years ago | (#39828017)

Actually if you just pulsed the magnets strongly enough, you could create an eddy current in the Al or Ti which then could still be pulled in magnetically. Oh wait, that has its flaws too...

Re:Flying magnets (1)

Yvan256 (722131) | more than 2 years ago | (#39825917)

Trapper Keeper. [wikipedia.org]

Re:Flying magnets (1)

FatLittleMonkey (1341387) | more than 2 years ago | (#39828809)

They're called pigeons, stupid.

Re:Flying magnets (0)

Anonymous Coward | more than 2 years ago | (#39829185)

But, how do they work?

good idea (4, Insightful)

fermion (181285) | more than 2 years ago | (#39824243)

It costs several dollars a gram to get it up there, it only makes sense to try to recoup some value. Reusing it does not nearly have the security concerns of forcing it down and burning it up.

Re:good idea (4, Insightful)

cpu6502 (1960974) | more than 2 years ago | (#39824443)

I don't see how this is workable. The space junk is spread-out across thousands of miles, and you'd waste a lot of fuel moving around trying to collect it all. Plus, what do you do once you have your pile of trash in your space vehicle? There's no engineers/technicians to assemble it into something usable.

A wiser course would be to outlaw leaving junk in space..... if you send a rocket into space, make sure to deorbit the spent stages immediately. If your satellite is EOL, then deorbit that too.

Re:good idea (2)

jellomizer (103300) | more than 2 years ago | (#39824613)

Who can take your trash out?
Stomp it down for you?
Shake the plastic bag and do the twisty thingy too?
THE GARBAGE MAN!!
Oh the Garbage Man can
The Garbage Man can and he does it with a smile and never judges you.
Who can take this diaper?
I don't mind at all
Who can clean me up before the big policeman's ball?
THE GARBAGE MAN
yes the garbage man can
The sanitation folks are jolly friendly blokes courteous
and easy going they mop up when your over flowing and tell you when
your arse is showing
Who can.....
Who can.....
Who can.....
Who can.....
THE GARBAGE MAN CAN!!
'Cause he's Homer Simpson Man
HE CLEANS THE WORRRRLD FOOOORRR YOOOUUU

Re:good idea (1)

squidflakes (905524) | more than 2 years ago | (#39824649)

http://www.youtube.com/watch?v=T5DnqW3F57E [youtube.com]

In spaaaaaaaaaaaaaaaaace!

Re:good idea (0)

Anonymous Coward | more than 2 years ago | (#39826427)

I believe this is what you're thinking of.

http://www.youtube.com/watch?v=HODkJABWo08

Re:good idea (2)

cornjones (33009) | more than 2 years ago | (#39824979)

A wiser course would be to outlaw leaving junk in space..... if you send a rocket into space, make sure to deorbit the spent stages immediately. If your satellite is EOL, then deorbit that too.

By who's authority would you outlaw something like that? how would you assign penalties to a chinese satellite that didn't deorbit properly? What about the thousands of objects already there? I think you need to head back to the drawing board. At least come up w/ sharks w/ laser beams or something cool..

Re:good idea (1)

cpu6502 (1960974) | more than 2 years ago | (#39825515)

Obviously the U.S. could only control its own companies & force them to deorbit stuff. Most-likely we could convince the EU to pass similar laws. That would eliminate the addition of ~99% new trash.

Re:good idea (1)

shentino (1139071) | more than 2 years ago | (#39825395)

And just how would such a "law" be enforced anyhow?

Space ventures are usually the prerogative of national governments who possess sovereign immunity and who may have something to gain from flouting such a law.

Re:good idea (2)

I_am_Jack (1116205) | more than 2 years ago | (#39825599)

And just how would such a "law" be enforced anyhow?

Right now it's solely being enforced by the Law of Gravity. I'm afraid, despite how necessary DARPA's proposal is, that it will be subsequently governed by the Law of Diminishing Returns.

Re:good idea (better idea) (0)

Anonymous Coward | more than 2 years ago | (#39825773)

The EDDE system at http://www.star-tech-inc.com/ seems to be practical.

Re:good idea (2)

SlithyMagister (822218) | more than 2 years ago | (#39826151)

A wiser course would be to outlaw leaving junk in space.....

I was tempted to mod this funny.
There is a common misconception amongst law-abiding people that making something illegal will change other people's behaviour, because they themselves change their behavour in response to a change in law.

As society becomes increasingly fragmented, the fraction of the earth's population that could be described as "law-abiding" is decreasing rapidly, and the process is further accelerated by governments that bow to the pressure of special interests.

Examples of laws that are defied or ignored abound.
Here on Slashdot we tend to revile copyright laws, and other IP laws.
Others openly defy laws controlling substances -- drugs, alcohold, tobacco etc.

Why on earth -- or above it -- would anyone abide by a "law" that would be ultimately unenforceable?

Re:good idea (1)

StormyMonday (163372) | more than 2 years ago | (#39826903)

So let the ion engine guys have some fun designing a "space tug". Pick up junk and tow it to a nice stable orbit somewhere, probably just outside geostationary orbit. Later, when we need a counterweight for a space elevator, we have a nice big hunk of mass that's already just sitting there.

For smaller stuff (paint chips and so on) I like the idea of a big sponge (open-cell foam) in an eccentric orbit. It'd make a few dozen orbits, pick up junk on the way, and then re-enter naturally (big == air resistance in LEO). It'd probably be really pretty, too.

concentrate on the doable.. space vacuums (1)

swschrad (312009) | more than 2 years ago | (#39826929)

outside of sending Newt up in a space suit with duct tape and a 9-ton oxygen bottle, since he's a spacehead and has lots of free time now, we really need to concentrate on gathering the krep into one place, and putting a blinking electronic "X" on the spot. this is doable, and since everybody is responsible, everybody needs to chip into the pot for a "free" project.

basically a robot dogcatcher with a very fine "net" is needed to close and capture the drifting trash. as to whether any of it is useable... good opportunity for technocrooks. send 'em up in an old Buick with suits, so they have the back seat as a workbench, and let 'em paw through the junkpile. if they can find a way to fly home in a space jitney, they're free.

Re: Thousands of Miles (1)

DanielRavenNest (107550) | more than 2 years ago | (#39832703)

Your comment makes the common mistake of Earthlings, that distance equates to cost. On Earth it does, because transport involves either rolling friction, air drag, or wave drag, depending on transportation method. In space none of these apply, so the cost of transportation is related to velocity change, and not distance.

Dead synchronous communications satellites are spread out in a 263,000 km ring around the Equator, but they are all moving at nearly the same velocity, the amount to match the Earth's rotation and make them synchronous, so gathering them up won't take much velocity change. Also, new electric thrusters are ten times as efficient as old chemical thrusters, and make a wider range of missions possible than before.

Some of the dead comsats are still functional, and just ran out of station-keeping propellant to keep them in a fixed location. The point of synchronous satellites is all the ground antennas don't have to move, cause the satellites stay in one place in the sky. Fixing those satellites just involves clamping on a new fuel tank and thruster pack, and you are good to go.

More advanced repairs would involve remote controlled robots, likely, to replace other items like worn out or broken solar arrays. Fixing internal failures, like the amplifiers for the downlink transmitters would need a hangar and humans given our current robot capability, so that level of repair will need to wait for lower cost humans in orbit. At the least, we can gather the space junk into controlled orbits so it doesn't breed more space junk by collisions.

Re:good idea (2)

raymansean (1115689) | more than 2 years ago | (#39824581)

The cost to launch DOD satellites is usually a small percentage of the over budget for the build of the satellite.
I am having a hard time with how we get things that were not meant to be interchangeable to link up in orbit to take on a new mission. Now if we could build a WALL-E (SPACE-E) that is capable of catching, manipulating, disassembling and construction of a new satellite that would be pretty impressive. However by the time we develop that technology we will have spent a considerable amount of money.
Perhaps the path forward is to develop satellites that can either connect (dock if you will) to the ones currently in orbit and use some of the preexisting equipment on board to perform a new mission, or build new satellites with a "SPACE-Port" that allows future satellites to dock with it and use the host's equipment. Right now I see the problem on the order of trying to connect a CDC 6060 with a K Computer.

Re:good idea (5, Insightful)

yesterdaystomorrow (1766850) | more than 2 years ago | (#39824595)

It costs several dollars a gram to get it up there...

The trouble is that most of that cost isn't lifting it to altitude, but getting it moving at the right velocity for the orbit you want. If you put some sort of recycling device in orbit, almost all of the junk that it encounters will be moving at high velocity relative to your device's orbital velocity. Speed will tend to be similar, but direction will be all over the place. Changing the velocity of either the device or the junk is difficult.

Lead is a reasonably valuable metal, but stationing yourself in no man's land between two armies and recycling the bullets that come at you seems a difficult way to obtain it.

Re:good idea (1)

taiwanjohn (103839) | more than 2 years ago | (#39831987)

The most plausible scheme I've heard is to use electrodynamic tether [wikipedia.org] propulsion to first collect the big stuff (spent booster stages, etc.) and move it to a central "junk yard" orbit. For the smaller stuff, they could use a pulsed laser to zap anything in range, giving a little nudge each time. Eventually this way you could slow it down enough to where it's orbit would naturally decay into the atmosphere.

Overheard in Cheyenne Mountain (5, Interesting)

idontgno (624372) | more than 2 years ago | (#39824247)

on a bright spring day in 2020:

Dammit. I think the Chinese just refurbished our operating commsats and used the parts in one of their early warning satellites.

Seriously. If you can do this with abandoned satellites, can you do it with not-quite abandoned ones? The only difference between junking a car at the junkyard and stripping a car on the street (besides location) is the fact that someone still owns the car on the street.

We're gonna wind up with satellites with no radio, no trim, and up on cinderblocks.

Re:Overheard in Cheyenne Mountain (3, Insightful)

SJHillman (1966756) | more than 2 years ago | (#39824299)

To continue your analogy... a car in the junkyard likely has nobody keeping an eye on it and has no alarms to go off if you try to force entry. A car on the street likely has the owner not too far away and will probably have some kind of alarm (if not security, then something operational that will scream if interfered with).

Re:Overheard in Cheyenne Mountain (4, Interesting)

AdrianKemp (1988748) | more than 2 years ago | (#39824343)

I wonder if someone at the table when the first satellites were being designed brought up the issue of (physical access) russian hacking once they were in orbit...

I imagine they probably did, huh? The paranoia at the time was incredible.

Re:Overheard in Cheyenne Mountain (3, Interesting)

Anonymous Coward | more than 2 years ago | (#39824513)

That is one reason why the Shuttle was designed to have such large wings, to handle landing from polar orbit per USAF requirements. The Shuttle would launch from Vandenburg, complete one orbit, grab a Soviet bird over the US/Eastern Pacific (out of sight of Soviet observatories), complete another orbit and land at Vandenburg again. The problem with launching from Vandenburg is that there's nowhere to the West of it to land without going to Hawaii, so the Shuttle would need the lift to glide back to Vandenburg upon reentry or else everyone would know something was up when the Shuttle was carried back.

Re:Overheard in Cheyenne Mountain (2)

moderatorrater (1095745) | more than 2 years ago | (#39825103)

I'd be surprised if this isn't a regular topic of conversation today. You're launching an incredibly expensive piece of equipment, often with national security repercussions. If you're not considering the physical security of it, then you're probably not doing your job.

Re:Overheard in Cheyenne Mountain (1)

JoeMerchant (803320) | more than 2 years ago | (#39824347)

That is why we need to get proficiency at doing it first.

One word: Backdoor (2)

Maximum Prophet (716608) | more than 2 years ago | (#39824467)

Because if they do, we will have backdoors into their spy satellites. Plugging a found USB drive you find in your company parking lot into your computer is an iffy proposition, plugging something into your satellite is just foolhardy. Best case, it's a bomb, worst case it's a monitoring device.

Re:One word: Backdoor (1)

myowntrueself (607117) | more than 2 years ago | (#39830931)

Because if they do, we will have backdoors into their spy satellites. Plugging a found USB drive you find in your company parking lot into your computer is an iffy proposition, plugging something into your satellite is just foolhardy. Best case, it's a bomb, worst case it's a monitoring device.

Ahhhh so THATS why the USA 'let' the Iranians capture that spy drone!!! It all makes sense now.

Re:One word: Backdoor (1)

Maximum Prophet (716608) | more than 2 years ago | (#39831667)

Hadn't thought of it in that context, but yes, the drone could have been intentionally crashed to detect holes in Iranian defenses. A flying Trojan Horse.

Most likely, the software wiped itself when the thing crashed, but it's not impossible that the drone had redundant copies of the flight software. Except one "copy" has the buggy or Trojan software and on crashing, the bogus version was moved into the flight areas. Or, there was a thermite charge above the brain, that slagged it down.

Re:Overheard in Cheyenne Mountain (4, Interesting)

0123456 (636235) | more than 2 years ago | (#39824517)

If you can do this with abandoned satellites, can you do it with not-quite abandoned ones?

Satellites are often abandoned due to running out of fuel. I've read that a number of new satellites are being fitted with a standard fuel connector so they could be refueled at some point in the future; no such 'tanker' exists yet but if the market is big enough someone may build it.

From what I remember another problem is that solar panel output declines over time, but that's probably a less important issue.

Re:Overheard in Cheyenne Mountain (1)

idontgno (624372) | more than 2 years ago | (#39825233)

OK, does civilization need to extend admiralty law to space? Legally, how do hulk ownership and "marine" salvage work? How about the Law of the Sea; for instance, orbit territory, laws of innocent passage, etc.

If we don't have something, we just have anarchy. And even at sea, where long-standing laws and treaties hold, we already have enough of that.

Re:Overheard in Cheyenne Mountain (0)

Anonymous Coward | more than 2 years ago | (#39829385)

I'd expect that they would get the windshield with the full service fillup.

Re:Overheard in Cheyenne Mountain (1)

wiedzmin (1269816) | more than 2 years ago | (#39826233)

Screw stripping it for parts, can we build one that will siphon gas from others? :)

Starting point towards asteroids (3, Interesting)

Neil Watson (60859) | more than 2 years ago | (#39824313)

Start with mining orbital junk before heading out to the asteroids. Must be plenty of useful metals and minerals to recover via automatic factories.

Re:Starting point towards asteroids (1)

Anonymous Coward | more than 2 years ago | (#39824543)

Trouble is, any given satellite is relatively small, and you use a lot of delta-v doing plane changes to match up with them all. Then again, despite being small, they're ready-made components instead of raw material, so there's that...

My prediction is, the first large-scale (as opposed to proof-of-concept stuff trying out the gear) orbital salvage operations will be in the graveyard orbits just above geosynchronous. They're some of the bigger birds (have to be, for high-bandwidth comms at that range), and have big/high-power solar arrays (one of the simplest components to salvage, if you're not trying to refurbish the whole satellite), and they're all clustered in pretty close orbits. Even if there's little demand for them in GEO (I think there will be, because they'll be much cheaper than launching new ones, expanding the market to countries/corporations that couldn't afford it before), you can collect a bunch of parts or whole derelicts and bring them back to LEO.

But of course, that does nothing for the LEO space-junk problem.

Re:Starting point towards asteroids (2)

squidflakes (905524) | more than 2 years ago | (#39824685)

Imagine the problems though, of trying to break apart systems that were never designed to be maintained, especially in microgravity.

At least with cars and motorcycles the engineers designed them to have parts replaced. How many comsats were designed in the same way?

Re:Starting point towards asteroids (0)

Anonymous Coward | more than 2 years ago | (#39825121)

That's what I'm saying about the solar arrays -- since they're generally folded in some way for launch, and extended afterwards, they hang out on one or a few struts which can be cut (including cables) and then you bring them back to LEO where technicians replace the wiring and assemble them onto new satellites. There's not a whole lot else a remotely-operated vehicle is gonna tear off for salvage (even destructively), let alone take apart cleanly, replace the broken whatsit, and reassemble.

Other than that, the most feasible thing is simply refueling and reprogramming old satellites. The refueling is a bit tricky, but given full design info on the satellite you're refurbishing, it's feasible to handle many cases with a reasonable selection of tools, adapters, and equipment. For satellites which are more-or-less functional (maybe some transmitters are dead, but there's enough operational to be useful) and retired due to running low on fuel, it's possible to buy them, refuel them and sell them. (Or refuel them for hire, but any that are already up there have been replaced with new ones already, so it's unlikely the present owner would have much use for the old one -- could be big business in the future, though.)

Good Idea (1)

Sta7ic (819090) | more than 2 years ago | (#39824359)

This is a really good idea, considering the fuel cost to get something up into orbit, plus the nonzero risk of the launch itself. Heck, if we can start with refurbishing 'orbital junk', we're getting into orbital manufacturing. Mix in an odd asteroid for raw materials, and we might actually get off this rock!

Re:Good Idea (3, Interesting)

johanwanderer (1078391) | more than 2 years ago | (#39824459)

There's a non trivial amount of fuel involved in changing an orbital object's speed, inclination, or trajectory: http://en.wikipedia.org/wiki/Orbital_maneuver [wikipedia.org]

Re:Good Idea (1)

cdrudge (68377) | more than 2 years ago | (#39824659)

Wouldn't the speed, inclination, or trajectory delta over a specified period of time determine how trivial or non-trivial the amount of fuel would be used?

Re:Good Idea (2)

AdrianKemp (1988748) | more than 2 years ago | (#39824867)

In fairness, DARPA isn't exactly about tomorrow's technology. They're about next decade's technology.

I see only two seriously hard parts to this (which makes it easy by DARPA standards)

1) capturing space debris tumbling and tossing about -- there was a recent contest announcement about just that, I forget if it was DARPA issued or not.

2) moving about in orbit without lugging the fuel to do it up with you. It sounds nigh impossible, but then that's what they *do*.

So you're absolutely right, and if it was any other department that was talking about developing this tech I'd call BS. But this sort of thing is right up their alley.

the inevitable movie... (2)

Tumbleweed (3706) | more than 2 years ago | (#39824447)

"Dude, Where's My Satellite?"

Japanese already did it! (3, Insightful)

Tastecicles (1153671) | more than 2 years ago | (#39824643)

Planetes [imdb.com]

Re:Japanese already did it! (2)

Tastecicles (1153671) | more than 2 years ago | (#39824739)

There's visual hints in that show from very early on, that even in orbits at the same altitude, minor deviations in orbital trajectory can cause objects moving at the same speed to close at ludicrous speed (for a pair of objects in LEO, each travelling at 17,500mph, the maximum mutual closing speed is 35,000mph - they're head-on. Even at only slightly tangential orbits of a fraction of a degree apart, they will close pretty fast. Possibly too fast to detect visually before a collision. A venture such as this will require very precise tracking of the debris (ground based?) and very precise maneuvering of the recovery vehicle to avoid a high speed collision which for anything larger than a panel pin would be a mission ender).

Lego Satellites (1)

Maximum Prophet (716608) | more than 2 years ago | (#39824661)

Modular refueling would be useful. Sometimes the only thing that dictates the life of a geo sat is the station keeping fuel supply. When it's about to run out, a geo sat is put into a graveyard orbit, where it's not supposed to hurt anything. If you could send up a small fuel supply ship that could pull a few sats from the graveyard, put the good parts together with perhaps new batteries and gyroscopes, you could get a much bigger satellite than if you had to launch a brand new one.

If you built your satellites with a fuel/engine section that had the gyros and anything that normally wears out, a solar panel section, and payload sections, so that you could pull them apart and put them back together Lego style, this idea might be workable.

2 + 2 = 5 (2)

turgid (580780) | more than 2 years ago | (#39824697)

X-37B?

What do you reckon?

Use it for more efficient thrust (1)

Marrow (195242) | more than 2 years ago | (#39825043)

Put an orbiter into an orbit that brings it into contact with a more massive dead satellite. Grab it. And use a magnetic servo or some other tool to hurl it downwards at Earth....and you go up. Maybe more efficient than spraying out mass using a booster?

wow. deep. @^*%. (0)

Anonymous Coward | more than 2 years ago | (#39825137)

Like the economics weren't blindingly obvious enough when they launched the effing stuff in the first place?

Time for a new company: Orbital Resources (1)

Baldrson (78598) | more than 2 years ago | (#39825305)

Planetary Resources is a good idea but the "low hanging fruit" is obviously in Orbital Resources.

Also, if there is technology developed to gather fragments in orbit, it should be feasible to use it to gather zodiacal light comet fragments -- appropriately scaled.

problem #1 (0)

Anonymous Coward | more than 2 years ago | (#39825415)

. . . for most platforms is either failed/failing batteries, or failed maneuvering systems (low fuel). To repurpose that, you've got to get TO the platform, and re-fuel, repair. We just mothballed our shuttle fleet.

There's the new spaceplane thing they've got, that's capable of rendezvouz, and changing orbits, but it's unmanned.
So, I don't see how they can pull-off a refuel/repair job, totally unmanned like that. STS succeeded with Hubble, what, 3? 4 times?

Avoiding the Kessler Syndrome (3, Interesting)

mcrbids (148650) | more than 2 years ago | (#39825487)

The problem is simple, and was predicted long ago: In the Kessler Syndrome [wikipedia.org] we have a cascading effect where every collision begets more collisions which create more, smaller bullets which impact... you see the cycle yet?

We really, desperately need to do two things:

1) Find a cheap way to collect the garbage.
2) Find a cheap way to get to space.

While rockets are nice and all, we really need something like a Space Elevator [wikipedia.org] or a ground-based Launch Loop [wikipedia.org] in order to commoditize space travel sufficiently that things like space-junk shielding can become the norm.

Also, why is all this junk going in all directions? It would seem appropriate to coordinate the launches and orbits so that there are "tubes" of orbit where everything goes in more or less the same direction so that collisions don't occur.

Aircraft do this - planes going east fly at odd elevations (11,000 feet, 13,000 feet, etc) and west at even elevations. (10,000, 12,000, etc) Why can't satellites?

Re:Avoiding the Kessler Syndrome (1)

DanZee (2422648) | more than 2 years ago | (#39825831)

Well, a space elevator is a good idea, but it would need to be incredibly strong. Might be able to make it out of carbon nanotubes, but chances are you would need something even stronger because of the stress caused by the 1000 miles per hour orbital speed of the earth, atmospheric drag, and so forth. Most satellites use the orbital rotation of the earth to provide a savings in rocket fuel, so they're shot towards the West. Spy satellites are often placed in a North-South polar orbit so they can photograph every square foot of the earth's. The height of the orbit often depends on what the satellite will be doing. Communication satellites have to be put into a geosynchronous orbit at 22,236 miles above the equator. There's no way around that without having to use multiple satellites like Sirius XM and fancy satellite tracking systems.

Re:Space Elevator (1)

DanielRavenNest (107550) | more than 2 years ago | (#39832787)

Only the simplistic single noodle stationary space elevator (devised in 1895 for gosh sake) needs Unobtainium for building materials. For a more practical design see this page in a space engineering textbook I have been writing (along with anyone else who contributes, but mostly me so far):

http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods/Space_Elevator [wikibooks.org]

The short version is that both rockets and space elevators get exponentially more massive with increased velocity. Therefore if you split the velocity to get to Earth orbit between the two methods, they *both* are much less massive than either by themselves. Thus a Skyhook type elevator that provides 2.4 km/s has a mass ratio of 16 times the arriving vehicle mass using existing carbon fiber and reasonable design margins (2.8:1 on the bare cable strength).

The rocket coming from the ground performs the remaining 6.6 km/s ideal velocity, and has a 13% payload fraction assuming LOX/H2 propellant. The ideal velocity is 27% lower than an unaided Single-Stage-to-Orbit rocket needs to do, which accounts for the higher payload. The Skyhook has a landing platform at the tip which the rocket does a vertical landing on. When returning to Earth, the rocket merely drops off the landing platform, and now has to dissipate slightly less than half the kinetic energy as returning from full orbit, so the heat shield problem is that much easier.

Re:Avoiding the Kessler Syndrome (1)

hAckz0r (989977) | more than 2 years ago | (#39827347)

I would suspect that a satellite in a high earth orbit with a good powerful laser could vaporize small amounts of material on the top leading edge of the space junk and effectively slow the junk down enough to be trapped by normal gravitation. As each piece of junk comes towards the craft the laser would give it a gentile nudge to slow it down just a little. Eventually they will slow enough and just burn up in the atmosphere. Powering the crafts laser would likely require a rather large RTG to generate enough power, or a huge solar array, just to keep the duty cycle high enough to do any good given the amount of junk flying around up there.

Don't set the bar so high (1)

AaronLS (1804210) | more than 2 years ago | (#39825827)

I wouldn't necessarily require that you be able to refurbish for less than it'd cost to build+launch new.

Instead, you should set the bar at "less than it would cost to (build+launch a new satellite)+(cost to remove debris used in refurbishing)".

If it costs $4 mil. for a new satellite, and $2 mil. to cleanup one satellite's worth of debris, but you can instead have a solution that uses that debris to create a satellite in orbit at a cost of $5 mil. then you've saved $1 mil. even though you did it at a costs greater than building a new satellite.

FiRst post (-1)

Anonymous Coward | more than 2 years ago | (#39826047)

Not anymore. TIt's beyond the scope of

YES! (1)

hesaigo999ca (786966) | more than 2 years ago | (#39826337)

I have said this atleast for the last 5 years, even before they retired the shuttle...I said, send it up there, and leave it up there, so instead of just rusting down here, it can be reused for its parts, and maybe get even more stuff built out there, then it would be with just the satellites.

Be Careful with This! (1)

bradorsomething (527297) | more than 2 years ago | (#39826871)

The Slylandro tried making probes that reused the materials around them... it didn't work too well.

Same set of tools in common with... (1)

hAckz0r (989977) | more than 2 years ago | (#39827113)

Note: prices stated below are just for dramatization, and are not thoughtfully calculated.

.
One android satellite development program, $3.8 trillion.
One heavy lift rocket to lift that satellite into orbit $3.7 billion.
One load of oxidizer/fuel mixture lifted into space to catch one low earth orbiting satellite, $5 million.
One dead US satellite in low earth orbit, return value $0.
One live Chinese spy satellite in low earth orbit, return value, priceless!

Funny how the same set of tools used to dismantle old broken US satellites is also approximately the same set of tools needed to dismantle and examine the Chinese, N Korean, or Iranian satellites, isn't it? Dismantling old broken US satellites will never be cost effective, but having knowledge of say Soviet and Chinese spy satellite technology is no doubt absolutely priceless. Of course I must be wrong, because the fine article never said anything about 'other peoples' satellites.

Katamari DARPA Damacy! (0)

Anonymous Coward | more than 2 years ago | (#39830585)

~doooooo, do do de doo do do dooooooooo~

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