Hubble Repair Mission At Risk

MollyB writes "According to Wired, the recent collision of satellites may put the Atlantis shuttle mission to repair Hubble in the 'unacceptable risk' status: 'The spectacular collision between two satellites on Feb. 10 could make the shuttle mission to fix the Hubble Space Telescope too risky to attempt. Before the collision, space junk problems had already upped the Hubble mission's risk of a "catastrophic impact" beyond NASA's usual limits, Nature's Geoff Brumfiel reported today, and now the problem will be worse. Mark Matney, an orbital debris specialist at the Johnson Space Center in Houston, Texas told the publication that even before the collision, the risk of an impact was 1 in 185, which was "uncomfortably close to unacceptable levels" and the satellite collision "is only going to add on to that."'"

Comments

hmm.

[apodyopsis]

we were discussing the debris problem at work over coffee the other day.

we were trying to find solutions to it in our non-expert fashion.

sadly the best we could come up with were:

(1) putting a impact shield around spacecraft - but the kind of impact speeds we are talking about probably makes this uneconomical as the shield would need to be massive.
(2) some kind of automated space cleaner that went around removing debris - but we had no idea how that could possibly work or be designed
(3) vastly improved tracking capabilities so we could avoid the worst areas and steer around them
(4) pre-emptive removal of dead satalites (no, not shooting them down from earth - attaching small moters to send them into the atmosphere) - maybe steering them into a declining orbit as the last thing they do before swithing them off
(5) just abandoning the whole outer space game anyhow and using a vast fiber optic ring on the surface for communication needs

there were probably other ideas that we came up with that I cannot remember, but this might get some comments/advice/derision.

but we all agreed, this problem will only get worse. and choosing different orbit altitudes only delays confronting the issue - but might be cheaper in the short term.

Re:hmm.

[Anonymous Coward]

Automated space cleaner... Perhaps a satellite that's solar powered and uses an electromagnet to repel pieces into the atmosphere? Although I suppose that would push it out of orbit... Maybe if there's enough air it could compress some and then use it as a jet to keep in orbit...

Planetes anyone? One of my favorites.
http://en.wikipedia.org/wiki/Planetes

Re:hmm.

[Rollgunner]

The problem with so many ideas to remove space debris is that most of them seem to add to the problem. Even microscopic particles can do tremendous damage at the velocities concerned.

The best idea I've come up with would be to send a cannister into the path of the debris to be removed at a slightly lower relative velocity. This device would then open, releasing a huge cloud of rapidly expanding resinous foam (think of the canned stuff you use to fill holes in the wall). The debris would then impact and become lodged in the hardened foam. The very large (but very low mass) object could then be caused to burn up in the atmosphere.

Then again, getting the canister up there will, of course, generate *more* debris...

Re:hmm.

[Firethorn]

As opposed to the fuel it's going to take to have the various other functional satellites, shuttles, and the station dodge all the time?

One idea I saw was to use an aerogel, that really sparse foam, to catch things. Well, set them closer to the deorbital path.

The idea is that the foam is so light that the wrench or whatever that hits it doesn't break up, the foam doesn't break up, so there's no additional fragments. Meanwhile, if you've set the orbit up right, the foam slows the debris down a tad, speeding up the time it'll take to hit atmosphere.

Re:hmm.

[Cally]

Re (4), deorbiting (or parking) dead satellites - this already happens to some extent, if vehicles are still commandable at EOL and have enough delta-v in the tank to make it to a high parking orbit (or a de-orbit burn), that's usually done. I've also seen tethers mooted as a fuel-free EOL mechanism for deorbit (winch out a 20km cable which drags through the upper atmosphere and burns off enough velocity to make the sc re-enter and burn up.) Problem is that all this costs mass, which means money. There's also the problem that lots of debris isn't under any kind of command (chunks of upper stages, satellites that died in action, dropped screwdrivers, slag from old Iridiums and and so on.)

Re:hmm.

[DarkAce911]

NASA has been kicking around the idea of a Space Tug and space vacuum cleaner. The cleaner would be a satellite that has some kind of sticky foam outer shell that will collect the small stuff.

Re:hmm.

[paiute]

Here's a thought. What if each spacecraft did not lug a big old shield up into orbit. What if we build an orbiting "overcoat" which had the necessary shielding and a space inside to accomodate the spacecraft.

And that overcoat is built by hauling material from the earth into space (with every transport flight being exposed to the very risk that now jeopardises the Hubble repair mission), putting it together there (with those unlucky astronauts who have to do this being exposed to the very risk that now jeopardises the Hubble repair mission), to then haul up the actual spacecraft (with that transport flight being exposed to the very risk that now jeopardises the Hubble repair mission).

You are not, by chance, an accountant, a corporate lawyer or a politician?

Some people choose to sleep with their pants on because they are reluctant to get out of bed in the morning and suffer cold legs.

Re:hmm.

[cowscows]

The best idea that I've heard about is the "laser broom". Basically big ground based lasers that shine up into space and hit orbiting junk with enough energy that they start to ablate. As the material ablates from the pieces, a small amount of thrust would be created, which would alter the pieces' orbits and eventually cause them to reenter the atmosphere and burn up.

It doesn't require putting any new material up into orbit, so you're not potentially creating even more matter up there to deal with. I think the biggest issue (besides economics) would be making sure that the laser doesn't damage any functional satellites, but that's not a hard problem to solve, as satellites are very closely tracked.

Re:hmm.

[TheGeniusIsOut]

Electro-magnets wouldn't do so well, since they will only work on magnetic materials. Large Van De Graaff generators, however, would generate static fields attracting most any object, or at least polarize their charges to the point that the Earth's geomagnetic field could get a grip on them, likely slowing them to the point of deorbit. These could be made cheaply, set into an orbital path to clear, and then burn up on re-entry when they have collected sufficient mass to themselves deorbit.

Re:hmm.

[Rich0]

Agreed. If you made some kind of inflatable aerogel or foam wall and put it into orbit then it would be bashed by debris, which would slow the debris down somewhat and speed their re-entry. The foam would have booster rockets to keep it in orbit (and keep it out of the way of active satellites). When those boosters run out of fuel, or something causes them to fail, then the huge mass of foam would rapidly deorbit since it would have a high drag:mass ratio.

You could even put the foam in retrograde orbit if you really wanted to slow down debris, although this might make it harder to keep out of the way of active satellites.

Soak up debris?

[MichaelSmith]

My thought is to fire a sounding rocket directly into the path of the debris. At the peak altitude the rocket explodes, releasing something like strips of foil which will collide with orbiting debris. Given time, it should be possible to clean up these orbits.

Re:Soak up debris?

[stevelinton]

I proposed something like this, but using something like snowflakes or small particles of dry ice instead of the foil, but it seems collisions at the speeds involved behave quite oddly and even "soft" targets can shatter pieces of debris into multiple smaller pieces mostly in pretty much the same orbit as the originals.

I wonder if some kind of magnetic drag could be devised? a big hoop of superconducting wire with a current in it that would slow down conducting debris that passed through it, but gently, so as to drop it into a more quickly decaying orbit.

Re:Soak up debris?

[MichaelSmith]

The objects we want to take out of orbit are in a stable trajectory. If they collide with an object fired directly from the ground they will lose some velocity and move into a lower orbit. Low altitude orbits decay quickly because of drag from the atmosphere so these objects will quickly burn up.

The object you fire from the ground to cause a collision will be shoved sideways a short distance. It can't go into orbit.

Having thought about it for a bit I think the best thing to send up in the sounding rocket is a bottle of liquid nitrogen. It will form an expanding cloud at orbital altitude. Debris which fly through the cloud will lose some speed and their orbits will decay. Sounding rocket firings could be timed to minimise impact on operational spacecraft.

Last paragraph is rubbish

[Kupfernigk]

You don't understand the Theory of Evolution. There is NO "next logical step" for a species which develops intelligence, and there is NO reason why not colonising space makes us a "dead end branch". As the late, great Jay Gould has pointed out, the main form of life on Earth (by biomass and by effect on the planet) is now, and has been for a very long time, bacteria. Bacteria achieve great adaptability without intelligence. If we cannot achieve the same adaptability, then environmental changes may make us extinct. But the test of evolutionary success is simply continued, unthreatened existence, not some hypothetical extension of range. If we "nuke ourselves", we've failed. If we learn to live in our existing environment without making it unusable, and adapt to its changes, we've succeeded. The idea that we must colonise space to validate our existence is a religion, not science.

Before the troll mods start up, please let me say I'm not objecting to exploring the Solar System in the slightest (in fact I think it's far more useful than the LHC). I am pointing out that your justification makes no scientific sense.

Re:Last paragraph is rubbish

[silanea]

If we fail to do this, then a global catastrophe will eventually happen which outstrips our technology and render us extinct.

So?

Honestly I could not care less. Not trying to troll, I really don't see an issue here. Humans have been around for some 200,000 years. Nice, but that is not exactly a long time span. Dinosaurs were around for more than 160 million years - 160,000,000, you notice the difference? And they still vanished. Humanity as a whole is quite insignificant, one amongst an uncountable mass of life forms in this planet, outlived (by time of existence, not concurrency) by most other species.

Why does everyone believe that we should be destined to walk this universe forever? Sorry, folks, hate to break it to you: The odds of that are damningly slim.

Big deal. By my estimation one of the following will have occurred well before our earth evolves to a point where living conditions will not allow us to adapt anymore:

• We will have suffocated from our own toxins, fumes and trash.
• Global nuclear armageddon, triggered by either a russian fascist, a chinese fascist or an american retard.
• God proves his existence - by hitting the reset switch.

I am really surprised, and somewhat concerned here. Supposedly /.'s target group should predominantly consist of engineers, scientists and generally geeks and nerds - people who rely on common sense and logic to make a living. (Not counting those working for Microsoft or Sun. Those have somehow mastered the forbidden art of producing systematically structured chaos.)

Re:Last paragraph is rubbish

[PhilHibbs]

Plus, it's worth noting that most species (including humans) that exist now do so precisely because they have repeatedly expanded their range.

However, when our ancestors were capable of adapting to survive the KT event, they were tiny little shrew-like creatures. And when our ancestors were capable of adapting to survive the big extinction 250M years ago, they were shrimps. In order to survive a global extinction level event such as a reeeeally big asteroid impact, we have to get off of this rock. In the long run, we as a species have already failed to survive because we are too specialised to quickly adapt to the inevitable forthcoming sudden, massive shift in climate that happens every few tens of millions of years. Evolution into higher life forms on a single planet is always a dead end because of this.

A possible shield

[Genda]

Since the trajectories of the debris will lie in a relatively narrow plane, it should be possible to device a barrier made of a plastic bag, shaped like a tube (open at both ends perpendicular to the plane of flying debris), and when inflated would make a tube like structure 6 inches thick and just slightly longer than the space shuttle and the Hubble combined. Fill the plastic cylinder full of water. The water freezes harder than steel. You now have an excellent barrier from the debris cloud while you work on Hubble. Now lift Hubble up a few thousand miles to get it out of harms way.

After, you can move water to the ISS for safe keeping. I'm guessing they can put an extra couple thousand gallons to use for anything from experimentation and raising space crops to providing water for the first space hotel. Not to mention if that water has minerals in it, it can be used for everything from dietary supplementation to an emergency shield against high energy solar emissions.

Re:Kessler Syndrome

[forkazoo]

What goddamn sci-fi show is it that has mentioned this name recently and made every nerd yell it at the top of their lungs as soon as space junk is mentioned in order to look clever?

Dunno if you count it as "recent," but (/me shouts:) PLANETES.

Except that

[Kupfernigk]

Will the inhabitants of those "off-world colonies" survive? We are far less likely to adapt to their conditions. The change of getting wiped out before sustainability is reached is rather high (look at the history of the colonisation of the Americas). Meanwhile, the amount of energy it takes to put even small payloads into orbit is enormous. We could easily reduce our planet to below sustainability in trying to create colonies, all of which would then fail for lack of resources. We've just done this to our economy by trying to make it expand too fast, so we have a track record.

Research on Earth into dealing with external threats such as infalling asteroids or comets, dealing with diseases, dealing with our own inbuilt tendency to commit genocide, is far cheaper and more likely to pay dividends. Let's protect ourselves from disease and space rocks first, then we will be demonstrating our adaptability and survival skills. Running for the hills is monkey behavior, dealing with the predators may be what made us human in the first place. After all, we could realistically have a basic comet and asteroid shield by 2030.

I repeat: the idea of space colonies is currently not even science fiction, it's religion. Which was my original point.

Calculating the odds

[jbatista]

even before the collision, the risk of an impact was 1 in 185

It's expectable that the risk of impact increases with mission duration. Therefore, how exactly is the risk of an impact measured this way?

"1 in 185" of what?

1 out of 185 two-week (for example) missions will yield one collision (on average)?

1 out of 185 orbits will yield a collision?

What else?

Re:No, it's not the end

[pnewhook]

In August 2004, O'Keefe requested the Goddard Space Flight Center to prepare a detailed proposal for a robotic service mission. These plans were later canceled, the robotic mission being described as "not feasible [washingtonpost.com]".

Just goes to show you cannot believe everything you read.

In reality, the robotic system was in manufacturing when it was 'canceled'. Goddard continued to fund a scaled back Hubble repair, but only a demo using a mockup robot and the hardware in Goddards full scale Hubble simulation labs. The demos finished as planned and were a complete success. Many of the operations were shown to perform better with robotics than with astronauts (like sliding out the instrument trays).

The planned body of the hubble repair robot is now the SPDM robot on the international space station. That robot already existed and hadn't yet flown to the space station due to the grounding of the shuttles at the time. Since the robot existed, the schedule, capabilities and cost were all feasible.

The robotics mission was canceled because Griffin didn't like the head of MDA (the robotics company contracted to build the robot portion of hte mission) as they had a rivalry when they both worked at Orbital. The whole 'unfeasible' story is a complete fabrication.