Slashdot Mirror
ISS Dodges Space Junk For First Time In Five Years
Kligat writes "For the first time since 2003, the International Space Station has utilized the rockets on the European Space Agency's Automated Transfer Vehicle to dodge leftover remnants of a defunct satellite. The Russian Cosmos-2421 was launched in June 2006 to track Western Navy vessels and is believed by NASA to have exploded — 'likely due to a self-destruct command issued by Russian officials' according to the article — leaving 500 pieces of space debris. Ordinarily, the rockets on the ATV are used to take the ISS away from Earth's atmosphere and reduce drag. In this case, the 5-minute firing caused the ISS to move downward because it was already near the top of its acceptable range. Estimated probability of impact was 1 in 72, and an avoidance maneuver is called for if the probability is greater than 1 in 10,000. The space junk was predicted to pass the ISS within just a mile."
You watch out for spy satellites!
Aren't orbital trajectories pretty well known? How is there a 1 in 72 chance that the thing will make a sudden mile-long jog and hit the station?
Russian news avoids mentioning the Russian satellite and just refers to the ISS dodging a "cluster of garbage."
NASA doesn't have any spy satellites. The Defense Department does. I wouldn't be surprised if there are a few fields of debris from US spy satellites that haven't been announced or anything. Such information is somewhat sensitive, and official denial may be important. Could be anything from 'protect the existence the other spy satellites in its family' to 'let's save face'. To be fair, I could totally see your DoD doing something similar.
in space so we could catch all the space junk? We just need to be careful that we don't catch any space stations by accident...
Considering who would be putting the net out there, what do you think the chances of accidently catching a space station (or satellite) are, hmm?
The Mothership
Would have to be a pretty tight net... small particles moving fast enough can rip a dangerous hole in spacecraft.
I'm not a rocket scientist. Is there another kind of drag that needs to be reduced?
The drag of being stuck in a space station! It's pretty much like being in prison, but when you stick some rockets on it, suddenly you feel like a supervillain!
what about Mega Maid? she could vacuum up all of the space junk
this post made me wonder. could they repurpose the nautilus anti missle laser system to knock the space junk that threatens the station out of the vacum of space. Or could it make things worse? (lots of tiny particles you can't avoid vs. a couple of big particles.
Depends on the error ellipse of the orbit determination for the junk, and it sounds like the uncertainty is a good fraction of a mile in size. But in any case, the miss distance is a mile after the course adjustment, not before.
I just mentioned that to my Martian friend, and he said "Gzornak frokka wa Hubble, flrckin earthling!"
Only if you know the secret code.....
They should attach large electromagnets to the ISS and collect all of the space junk it passes by for recycling. I wonder what payment the recycling depot would give for satellite parts.
I don't keep track of shuttle payloads, but I would imagine that there would be room for a satellite or two in the cargo bay on the return trip.
That's a heck of a close call, considering the ISS is traveling at 4.8 miles per second. That's little like a car at highway speed running a red light and missing another car by less than one car length.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
Here's a graph of ISS altitude for the last year, if anyone is interested in hard data. (The steady downward slope is due to atmospheric drag, and the sharp increases are from firing maneuvering thrusters to maintain altitude. Presumably, the recent abrupt drop was the maneuver described in the article.)
maybe they were just quoting the engineers who had built the satellite...
It's very good. And it's the only anime I've seen where there's no sound in space.
Mada mada dane.
[intercom:] "(sszzkk) uh, we need a cleanup on mile 183... that's a satellite cleanup on mile 183."
> ISS Dodges Space Junk For First Time In Five Years
It must be really banged up after 5 years of hitting space junk.
Admit it! You thought it too!
The calculated miss distance was about a mile, but there was uncertainty in that miss distance such that there was a 1 in 72 chance it wouldn't miss the ISS, but instead hit it directly.
To answer your question (at a high level), the sensors and models that are used to track and predict the debris locations have associated mathematical models that can put a number on the uncertainty of where that debris is. The uncertainty takes into account things like how many radar obs were made, the inherent accuracy of the radar, uncertainties in atmospheric drag, etc. You can never know exactly where an object is, only an approximation of the current and future location and a mathematical confidence in that estimate. In this case that confidence was sufficiently low (and the risk of impact high enough) that a collision avoidance maneuver was executed.
Worst...sig...ever!
The problem with this theory is that there are about 100,000 geeks in the world that love nothing more than to tag every single man made object in space. They even have programs to show every bit in real time graphically orbiting the planet. Many of these are free for download.
You can't put or have anything in space bigger than a small stone and not have some government or organization find and tag it, only to release that data to the general public at some point not very long after that. Lots of RADAR being pumped out in to space just for this very purpose.
If the ISS was moving because of anything other than debris from a Russian spy sat, then the slashdot headline here would spell it out. Even the military make use of the work from these guys, it can sometimes actually be more up to date.
Me: Ex 3 letter agency drone that worked in the satellite area for a while.
The central ISS modules (Zarya, Zvezda) are Russian. Actually, the docking port the ATV is using is also Russian, using the "probe and drogue" technique. I would call their contribution quite remarkable.
You wish. There are over 140 US objects tracked by us amateur satellite trackers which are classified - i.e. they officially do not exist and the only public data on their orbits comes from us amateur trackers. Not NASA, the DoD or any other US government agency.
Ceterum censeo Carthaginem delendam esse
+ Informative adds to karma while + Funny does not. "Helpful" mods have been rating comedy posts as Informative to give the poster better karma. This practice fucks up the karma system and needs to stop. Unfortunately, stopping this probably won't be easy.
Then again, maybe I should lighten up and not care so much about this.
Said, "It's just like dice but it's got more sides And it tells me who lives and who dies"