Something remarkable happened yesterday at about 780 kilometers above Siberia. Love was in the air vacuum at first sight encounter between a U.S. satellite, Iridium 33, and a Russian one, Kosmos-2251. And they immediately multiplied and prospered into at least 600 and increasingly counting descendants set to enjoying high flying life styles for years and decades to come.
I call the above spin an example of positive thinking. But somehow some people on earth insist to worry. Besides the general concern of dangers posed to the international space station and future space programs by the resulting debris cloud, there is the question of what would happen to the remaining satellites in the Iridium constellation, which provides communication services to areas not covered by traditional cellular systems. BBC News quoted Richard Crowther, an expert on space debris and near-Earth objects as saying:
Unique to the Iridium system is that all the remaining 65 satellites in the constellation pass through the same region of space – at the poles. So the debris cloud that is forming as a result of the Iridium satellite breakup will present a debris torus of high (spatial) density at 90 degrees to the equator that all the surviving Iridium satellites will need to pass through.
In other words, there is a danger that a second Iridium satellite would collide with a piece of the debris, resulting in more debris and thus increasing the danger for the reminder of the constellation further. It’s not difficult to imagine, at least theoretically, a cascade of increasingly frequent collisions that would eventually destroy all of the Iridium satellites.
Sounds familiar? That’s essentially how nuclear fission works in the, you know, boring old atomic bombs.
Iridium’s trouble, however, is just a particular example of the danger faced by space programs in general. Come to think of it, the danger discussed in a New York Times article published almost exactly two years ago all of a sudden seems a lot more relevant.
Today, next year or next decade, some piece of whirling debris will start the cascade, experts say.
“It’s inevitable,” said Nicholas L. Johnson, chief scientist for orbital debris at the National Aeronautics and Space Administration. “A significant piece of debris will run into an old rocket body, and that will create more debris. It’s a bad situation.”
…
Cascade warnings began as early as 1978. Mr. [Donald J.] Kessler, [a former head of the orbital debris program at NASA and a pioneer analyst of the space threat], and his NASA colleague, Burton G. Cour-Palais, wrote in The Journal of Geophysical Research that speeding junk that formed more junk would produce “an exponential increase in the number of objects with time, creating a belt of debris around the Earth.”
…
If nothing is done, a kind of orbital crisis might ensue that is known as the Kessler Syndrome, after Mr. Kessler. A staple of science fiction, it holds that the space around Earth becomes so riddled with junk that launchings are almost impossible. Vehicles that entered space would quickly be destroyed.
Feel doubtful? The European Space Operations Centre has some concise descriptions and exaggerated artist’s impressions to illustrate this very problem.
The NYT article was written in response to China’s successful testing, in January 2007, of an anti-satellite missile that shattered an old weather satellite into one thousand observable pieces. Xinhua, incidentally, supplemented its reporting of yesterday’s event with fairly well researched background information. For reasons unknown to me, the Xinhua article somehow failed to mention China’s impressive engineering feat two years earlier.
At the beginning of this year, there were roughly 17,000 pieces of man-made debris orbiting Earth, said Nicholas Johnson, chief scientist of NASA’s Orbital Debris Program Office at the Johnson Space Center in Houston.
Last April, scientist at the American Physical Society conference in Los Angeles said there were already more than 150 million pieces, among which a large amount were junks created by astronauts. They predicted that the amount would still increase in the next 200 years.
Early statistics showed that about 45 percent of space debris was produced by the United States and 48 percent by Russia or former Soviet Union. China produced only 1.2 percent.
Ahh! The Kessler Syndrome could become a reality! I was almost ready to panic when my good habit of positive thinking kicked in again. No wonder we haven’t suffered the Independence Day fate yet. All of those ill willed and technologically advanced aliens must have gone through the same development path as ours and managed to seal themselves inside their planets with alien-made space junks. Now I can rest easy. Oh and there might even be one more benefit coming out of the debris in the sky. These objects, once sufficiently shattered and spread, could even work to solve the global warming problem for us as well.
So next time your kid asks if he/she could host a visit by E.T., tell him/her that E.T. cannot come because his spaceship is blocked inside the home port.
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And here are a few tit-bits that may be amusing only to me:
- Some readers probably have recalled a scene in the Pixar movie WALL-E, in which a probe spaceship has to force its way through a thick layer of space junk to leave earth. It has been pointed out that one of the satellites brushed aside is none other than Sputnik 1.
- It is well known that the Iridium system was named after the element with 77 protons and 77 electrons because it was initially designed to have 77 active satellites. After the design was finalized with a reduced satellite count of 66, however, the name wasn’t updated to Dysprosium, the element with 66 protons and 66 electrons. As it happens, root of “Dysprosium” means “bad approach”. Given the unfortunate history of the Iridium system since its launch, that might have been a more fitting name.
- There are now voices worrying about geopolitical consequences of such collisions in the future. And some are already seeking to assign culpability in this case. As quoted in the Aviation Week:
James Lewis, a senior fellow at the Center for Strategic and International Studies, said he is “interested to know, does Iridium have a case against the Russians?” Clearly, he said, there was some negligence involved on someone’s part. “I don’t think we want this one to go away quietly, like ‘Oops, this was just a natural event.'”
Psst., James, the Russian satellite claimed its orbit 6 years before the Iridium one.
[UPDATE] Steve, in comment #2, just made a good point:
Seems like someone should invent a space vacuum cleaner to suck up all the debris from the current ones.
That’s it. It’s time for a Mega-Maid to be introduced. For background, see the movie Spaceballs.
Charles Liu says
Don’t most of the space debris from the collision will descent and burn up right away? Whatever is left will eventually get pulled into the atmosphere, no?
Steve says
@ Charles: Depends on the altitude of the debris. Beyond a certain altitude, it’ll just float there. It might be a good idea in the future for all satellites to sit at an altitude where they’ll eventually fall back towards the earth and burn up. Seems like someone should invent a space vacuum cleaner to suck up all the debris from the current ones. 😛
FOARP says
I’ve also been worried for a long time about A-Lian.