Monthly Archives: March 2009

near-earth asteroids, NEOs

Asteroid Threats

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What Will Our Global Response Be When One Comes Knockin’ at Our Door??

In the event that our planet is actually threatened by a collision with an asteroid — that, say, astronomers find that a small rock that can do devastating damage to Earth is actually on a collision course — what will we do?  Whenever this question comes up in public discussions, there’s always somebody who says, “Nuke ’em!”  without regard to the difficulties that sending nuclear bombs out to space to intersect fast-moving asteroids can pose. Yes, it can be done. Anything is possible, given enough time, money, and warning.Yet, is it that easy?  How would it really come down if astronomers said that something was going to whack Earth and we had XX days or months to do something about it?  I can pretty guarantee you that it wouldn’t be like it is in the movies. The whole process would be a whole lot messier and political.

Contrary to the “Duck and Nuke ‘Em” school of thought, the decision to send bombs or laser bursts out toward incoming space shrapnel wouldn’t be taken unilaterally. The United Nations would need to be involved, as well as all the world’s space agencies. Is there a communication program in place so that the UN and the agencies can talk about what to do — quickly and efficiently?  Who would get tapped to make the decision?  Toss the bombs or aim the lasers?  Or is there another alternative? How would we warn the populations of the areas that would be likely to be hit by debris?  What political implications would there be in these decisions? What’s it going to cost? What are we doing now to find these NEOs and predict their orbits?

Well, as it turns out, there are people who are worried about how this will all work. And they’ve issued a report that’s worth looking at. It’s a downloadable PDF and the name of the report is Asteroid Threats:  A Call for Global Response. The authors comprised a committee of experts led by former astronaut Rusty Schweikert; they considered the issues relevant in finding these near-Earth asteroids, and predicting their future orbits and possible collisions, and what we should do in the event one is going to hit the planet. The committee members are part of the Association of Space Explorers (made up of astronauts and cosmonauts — the kind of folk who work in space for a living).

The recommendations in the report have been disseminated in the past three months within the UN.  Schweikert notes that the report has been favorably received, follow-on internal documents are in editing, and the work is incorporated in the approved three-year work-plan for the UN committee on peaceful uses of outer space. So, click on the link above, download their report and have a look at it.

astronomy, satellite collision debris

Junk Orbits

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Messing up LEO and Endangering ISS

Recall a few weeks ago we had a little “oopsie” between a couple of satellites that resulted in both of them being broken apart into small chunks of debris. Some of that debris has started to fall through the atmosphere, and will likely burn up as it passes through or if any pieces survive and fall to Earth, they’d be “ghosts” of their former selves.

However, some of this material (tastefully renamed Micrometeroid Orbital Debris) could very likely pose a threat to the International Space Station. According to the NASA watch board NASA Spaceflight.com, the crew of the space station has been alerted that they may have to  move into the Soyuz capsule and possibly be prepared to leave the station due to a “red threshold late notice” they received about debris that could slam into the station. Given all the factors that affect the orbits of debris, it’s still not clear as of this morning (Thursday, March 12) whether the team will have to do this. (It’s getting clearer — see updates below.)

Note:  The piece of debris was a piece of a Payload Assist Module (got that info from the link above).  The ISS really dodged more than a bullet!

A satellite with a PAM-D upper stage attached. A piece of the PAM-D from the recently-collided Iridium satellite is what passed by the International Space Station today.
A satellite with a PAM-D upper stage attached. A piece of the PAM-D from the recently-collided Iridium satellite is what passed by the International Space Station today.

This problem raises the issue of just what we’ve done to junk up near-Earth space. It’s not just this satellite collision that groatied things up.  There has been space junk out there for years, ranging from stuff dropped during EVA missions to junk from intentionally destroyed satellites. It’s all out there, either raining down after years of atmospheric drag or plugging along in orbit, waiting for a chance collision with something like ISS or, worse, a shuttle or other launch vehicle ascending to orbit.

We’ve junked out Low Earth Orbit now — and there’s not a lot we can do to clean it up.  We have to dodge the junk in order to get to space, and once we’re there, we have to watch out for it.  Although space is big and the junk is small, this is still just a bit too much like the work-arounds we live with here on Earth to avoid drinking polluted water or breathing crappy air.

The good news  is, provided we don’t further scatter our stuff around LEO, given time and atmospheric drag and a few other factors, orbits will get clean again, but that’s little consolation to the folks who have to live with it (literally) on orbit.  Now we need to find ways to actively clean up LEO.

Late note: according to Nancy Atkinson over at Universe Today, the crew is shutting down hatches on ISS and will head for Soyuz from 16:30 to 16:45 GMT Thursday. The possible debris hit could be in as little as 40 minutes from now (now being around noon on the U.S. East Coast).

Even later note:  the piece passed by and didn’t hit the ISS.  We can all breathe again.