NASA Postpones Spacewalk Citing 'Debris Notification' for ISS (theguardian.com) 13
Nasa has postponed a planned spacewalk outside the International Space Station due to flying "debris," two weeks after Russia blew up one of its own satellites in a missile test that created clouds of zooming shrapnel in orbit. From a report: Washington's space agency did not mention the Russian test in its announcement, but a Nasa official had warned a day earlier of a slightly elevated risk to astronauts due to the 14 November incident. The strike generated thousands of pieces of "space junk" that are now hurling around the Earth at about 17,000 mph (27,400km/h) -- much faster than the speed of a bullet. At that velocity, even tiny flecks of paint can damage spacecraft, with spacesuits even more vulnerable.
On Tuesday, about five hours before the astronauts Thomas Marshburn and Kayla Barron were due to venture outside the space station, Nasa said on Twitter that the spacewalk to fix a failed antenna had been cancelled. "Nasa received a debris notification for the space station. Due to the lack of opportunity to properly assess the risk it could pose to the astronauts, teams have decided to delay the 30 November spacewalk until more information is available," it tweeted. Moscow has said its test to destroy its own spacecraft, Tselina-D, which had been in orbit since 1982, was successful and the debris posed no "threat to space activity."
On Tuesday, about five hours before the astronauts Thomas Marshburn and Kayla Barron were due to venture outside the space station, Nasa said on Twitter that the spacewalk to fix a failed antenna had been cancelled. "Nasa received a debris notification for the space station. Due to the lack of opportunity to properly assess the risk it could pose to the astronauts, teams have decided to delay the 30 November spacewalk until more information is available," it tweeted. Moscow has said its test to destroy its own spacecraft, Tselina-D, which had been in orbit since 1982, was successful and the debris posed no "threat to space activity."
Why not invite a Russian astronaut... (Score:5, Interesting)
Since the Russian government thinks it is so safe after their test.
Re: (Score:3)
The Cosmonauts are to busy at the telescope looking at NATO troop movements in Eastern Europe.
Cue the Rusophobic Fake News! (Score:1, Funny)
This is why we can't have nice things! (Score:3)
Threat to who's activity? (Score:3)
Moscow has said its test to destroy its own spacecraft, Tselina-D, which had been in orbit since 1982, was successful and the debris posed no "threat to space activity."
Any/all space activity or their space activity?
Re: (Score:2)
They dont have enough current or planned future space activites (can't afford it) to worry about their space activity.
They just don't want someone else to play where they can't. Or they are trying to make it more expensive for everyone else, since they can't do much there.
My job is satellite collision avoidance; AMA (Score:5, Insightful)
We don't have the Kessler syndrome. Yet.
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Well, what is the yearly probability for it to happen, at the moment? Can it be estimated? Which orbits will it affect most?
Asking for a friend.
Please Dont Upset Mr. Bigglesworth. (Score:1)
Speed of the orbital debris? (Score:2)
It doesn't really matter how fast the debris is traveling in space. The ISS itself is traveling at orbital velocity, about 17K MPH. How fast is the debris cloud moving, RELATIVE TO THE ISS? If the debris cloud is traveling at a substantially different velocity, then it's in a different orbit, and will either rise above the ISS, or descend beneath it - and anything moving below the ISS will soon get low enough to encounter traces of atmosphere, causing it to deorbit.
That was the biggest flaw with the movie
Re:Speed of the orbital debris? (Score:4, Insightful)
That's a pretty limited view of the orbital mechanics involved, because it assumes everything is in the same orbital plane, and the only way to maneuver is to go faster/slower/higher/lower.
The ISS is at a 51.6-degree inclination. One could have a debris cloud at exactly the same altitude and speed (27,500 kph), but at an inclination of 0 degrees, and the closing velocity would be 27500*sin(51.6) = 21550 kph. I daresay that's fast enough to cause damage! (A polar orbit collision would be less dire - only 17000 kph.) And those two orbits cross every 45 minutes or so.
And since it is a cloud of debris, where each bit has a slightly different velocity, pretty soon there will be bits that drift to fill the entire orbital circumference, and at a bit higher and lower altitude, and at a bit higher or lower inclination. But any bit of debris that happens to be in the vicinity of the ISS would still have a relative velocity 20x faster than a bullet.
Re: (Score:2)
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Sigh. If you really wish me to do more research and math, rather than figuring it out yourself...
From spaceflightnow.com: