Low Earth Orbit Junk Yard Nearly Full

vlado4 writes "The New York Times has up an article on the amount of space junk in Earth Orbit. According to NASA officials, the amount of stuff we've put into LEO is at critical levels. Additionally they have great graphics of the nearly 1000 new pieces resulting from testing the new Chinese anti-satellite weapon, as well as the damage to Hubble's solar array. The litter is now so bad that, even if space-faring nations refrained from further interference, collisions would continue to create more clutter just above our atmosphere. Space debris appear to be a difficult problem to deal with and may hinder future space exploration."

CERISE satellite

[amightywind]

A year later, apprehension rose as the fuel tank of an abandoned American rocket engine exploded, breaking the craft into 713 detectable fragments -- until now, the record.

The NYT calls out the US but makes no mention of the the loss of the CERISE satellite [seds.org] by a fragment of an exploded Ariane upper stage in 1997.

Re:But seriously...

[Annirak]

It is NOT easy to maintain cryo temperatures in space. Disposing of heat in space is quite difficult, as your only means of heat loss is radiation and the sun tends to shine on whatever you're cooling most of the time.

Re:How bad are we?

[Intron]

Not really. Decay time due to drag for LEO is fairly short. Debris in orbits below 300 km (where ISS lives) falls in less than 30 days. Debris up by the Hubble can stay up for years, but will fall eventually. Here is a chart [spacefuture.com] of orbital decay vs. altitude.

Planetes

[Pwipwi]

Reminds me of that manga called "Planetes" about a team of space debris cleaners.

The story started as a discovery-type vessel got hit by a screw which led to a window exploding, killing everyone.

It's a pretty good reading imho, very informative for what's about to come in the space exploration adventure.

Re:How bad are we? Oceans too!

[Nom du Keyboard]

Not only are we destroying our own environment, our planet is surrounded by floating trash.

And so are our oceans -- 2 millions tons of it according to an article I saw yesterday.

Re:Planetes

[EightySeven]

http://en.wikipedia.org/wiki/Planetes [wikipedia.org]

It was made into a great (and I mean GREAT) anime as well.

The story of Planetes takes place in the near future. Unlike many other anime and science fiction productions, special care was given in Planetes for a very realistic depiction of space and space travel. For instance, when in a weightless environment, the cel count dramatically increases in order to make weightless motion more fluid and realistic. Also, spaceships make no noise in the vacuum of space and astronauts routinely suffer from known space illnesses such as radiation poisoning, decompression sickness, cancer, brittle bones and mental illnesses spawned from isolation in the vacuum of space. One character, born on the Moon, grew to be abnormally tall due to the lesser lunar gravity.

Concepts like momentum in weightlessness are early plot points and are always illustrated naturally. Director Goro Taniguchi stated in the DVD commentary that he learned much about orbital mechanics in the course of making the series. This can be shown in showing specific orbital energy, through changing orbits by applying thrust throughout the series. Even the necessity for the retrieval of space debris that is central to the plot is rooted in the serious and growing problem with space debris today.

Re:Oooo pretty rings

[Anonymous Coward]

Planets form rings over hundreds of thousands to millions of years. Perhaps it will form a thin ring, but we'll never see it (unless we launch a lot more junk up there around the equator). Planetary rings are temporary BTW.

a couple of stats

[White Yeti]

At 850km, the "lighter" objects (high area-to-mass ratio, e.g. insulation, thin plates) will decay within 30 to 60 years. A 1cm steel sphere at that altitude, for example, will only drop about 80km over the next 100 years.

NASA's Orbital Debris Quarterly News [nasa.gov] has general articles, and always ends with a launch table and "box score". We'll have to wait for the next issue, but China has more than tripled its cataloged debris. With this one event, it's now got about a quarter of what the US and Russia each have, pulling well ahead of France and locking in its position in 3rd place.

I'm really curious about what's going on behind the Chinese wall. I know that NASA in no way controls what the US DoD does in space, and can only nag [iadc-online.org] the administration to keep its promises [nasa.gov]. NASA scrambles the same way no matter who does the test. Does the Chinese Minsistry of Science (or whatever) butt heads with the Ministry of Defense? I look forward to reading the history, many years from now.

Not really an issue

[cyberanth]

First, this is not a permanent problem. It does not take long for an abandoned LEO satellite to decay, fall into the atmosphere, and burn up. Second, imagine about 1000 cars on a surface slightly larger than the earth (not even addressing that LEO satellites are in a pretty wide variation of altitudes). Now image these 1000 cars just driving around the earth in random directions. Collisions seem unlikely. To be precise, is we put the satellites all at 7000km from the earth's center, we have an area A = 6 million km^2. Now, give them roughly the area (actually circumference in 2D) of lets say a bus (to be generous), that be sigma = 6e-2 km. Thus, that gives us a mean free path of l = (1000*sigma/A)^-1 = 10,000,000 km. At a LEO orbital velocity of 7.8 km/s, that would be a collision every 14 days. And if we bumped it up to the full 3D problem, that'd be another couple orders of magnitude.

Re:How long will it stay up there?

[SeanAhern]

Um...On the second page of TFA:

The breakup was dangerous because the satellite's orbit was relatively high, some 530 miles up. That means the debris will remain in space for tens, thousands or even millions of years.

"Sooner or later" ends up being much, much later.

Re:Collect it, yes. Throw it away, no.

[Rei]

Because those "chowderheads" are aware of the facts that:

1) We have no space tugs
2) Space tugs still cost money to operate (ion engines still use fuel, just less of it)
3) All craft break, even tugs, and in-space maintenence is ungodly expensive
4) Due to widely differing debris orbits and the need to match your target's orbit, it could take an ion engine years *per particle*.
5) The stuff is seen as junk for a reason.
6) There is no in-space forge, either researched or built or launched. Developing one would be a massive (unfunded) research project
7) There is no in-space casting facility. See above.
8) There is no in-space welding infrastructure. See above.
9) Any in-space manufacture would cost a fortune due to the extremely high labor and maintenence costs.
10) Any of the necessary components (tug, forge, casting, welding) could outright fail, making the entire system worthless.

All for what benefit -- eliminating one launch per several *thousand* pieces of debris captured? Great plan there. It's just not realistic, nor economical. Apparently non-"chowderheads" aren't aware of this.

Re:How bad are we?

[careysub]

Not really. Decay time due to drag for LEO is fairly short. Debris in orbits below 300 km (where ISS lives) falls in less than 30 days. Debris up by the Hubble can stay up for years, but will fall eventually. Here is a chart of orbital decay vs. altitude.

This is correct. At low enough altitudes space debris does not cause a run-away debris scenario. This point was made in the New York Times article - if the Chinese had conducted their test at the ISS orbital altitude there would be no long term problem (just a medium term one for the ISS).

In fact drag automatically clears debris below about 700 km, eventually, but not above that altitude. There was a good article on this a year ago in Science: "Risks in Space from Orbiting Debris" by Liou and Johnson (20 January 2006: Vol. 311. no. 5759, pp. 340 - 341). They published a debris vs altitude chart for 2004, 2104, and 2204 showing that (assuming nothing else is launched into space), the existing debris cloud would be entirely cleared below 400 km in 100 years, and at least reduced below today's density between 400 and 700 km. Above that altitude the density keeps climbing century after century. By far the worst hazard is between 800 km and 1050 km.

This limits the hazard to a certain band of orbital altitudes, a fact not brought out in the news article. It isn't a denial of space by any means, but it is a significant restriction on usable orbits.

Re:No problem

[Rei]

Picture trying to pull a moped off the road at 60 miles per hour.

Now increase the speed of the moped threehundred fold (and its energy almost a hundred thousand fold). Think that will work? No? Bingo. You wouldn't even change the orbit measurably if it flew past a just centimeter from your magnet.

You can take out debris by many methods, such as: applying direct thrust to it (say, attaching a small engine); subjecting it to more drag (say, attaching a sail to it to drag through the rarified atmosphere, or increasing the rarified atmosphere); rendering it into small enough particles that either cannot do enough damage to be problematic, will reenter soon (greater surface area to mass ratio), or most likely, both at the same time; colliding it with a target (having either the debris be either largely contained or disintegrated, as per above); etc.

mode parent up Re:An idea who's time has come?

[Fubari]

This is *hugely* interesting.
This looks at the economics of how "space garbage collectors" might be managed.

"Planetes" is an outstanding anime - *very* well thought out for the medium-term future of space development. It has a richly envisioned, deeply layered world w/Power struggles (political, corporate), collapse of petroleum economy, widening divide between 1st & 3rd world economies. It is a Very well crafted series; a rich tapestry woven of thought provoking ideas.

The gui "interface" they designed for the space suits is reason enough to watch it. It is Frickin' Cool!

The story line is Exceptionally well done, too.
(Oh yeah, first rate animation is a bonus; nice to see, too.)