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Swift
2009-Mar-12, 04:46 PM
From CNN.com (http://cnnwire.blogs.cnn.com/)

ISS crew goes into Soyuz capsule while debris passes by
Posted: 12:39 PM ET
(CNN) — Orbital debris from a prior space shuttle mission is forcing the crew of the International Space Station to retreat to its Soyuz capsule temporarily, NASA said Thursday.

Swift
2009-Mar-12, 04:47 PM
Here is what NASA has to say

Station Crew Takes Precautionary Measures Due to Space Debris

International Space Station Expedition 18 crew members are taking precautionary measures due to space debris that has been determined to be within the range where a collision is possible. News of the close approach came too late for flight controllers to coordinate an avoidance maneuver. A portion of a spent satellite motor is within the distance of the station's debris avoidance maneuver requirement "box."

Crew members are entering their Soyuz TMA-13 capsule and soft-locking the hatches, in case the debris should affect the space station and they are required to undock. The closure of the hatches ensures the safety of the crew and the ability to quickly depart the station in the unlikely event the debris collided with the station causing a depressurization.

The time of closest approach of the debris to the station is 12:39 p.m. EDT. Once the object is clear of the station, the crew will exit the Soyuz and reopen the hatches.

The crew will be in the Soyuz from 12:35-12:45 p.m. EDT. They will remain in the Soyuz until the debris risk has passed. Moving the crew into the Soyuz is a precaution, as the probability of impact is low. The crew is currently putting space station into an unmanned configuration, including several interior station hatches.

Tucson_Tim
2009-Mar-12, 04:47 PM
ToSeeked :) (but only by 30 mins)

http://www.bautforum.com/universe-today-story-comments/85829-iss-crew-may-need-evacuate-possible-debris-hit.html

Buttercup
2009-Mar-12, 04:51 PM
The debris situation is only going to get worse.

Sad.

Murphy
2009-Mar-12, 05:04 PM
in case the debris should affect the space station and they are required to undock.

Ha, I like the NASA "play it down" language. Translation: in case the space station is blown to bits and they are force to make an emergency escape. :lol:

samkent
2009-Mar-12, 05:38 PM
Was that the best decision?

If the object were to hit Soyuz, wouldn’t it likely go through the bodies of multiple astronauts?

If it were to hit the station wouldn’t they want to make a effort to plug the holes before abandoning the ISS? The size of the holes would be small compared to the volume of the station. Plus the likelihood of hitting more than one astronaut would be greatly reduced.

cjameshuff
2009-Mar-12, 06:15 PM
If it were to hit the station wouldn’t they want to make a effort to plug the holes before abandoning the ISS? The size of the holes would be small compared to the volume of the station. Plus the likelihood of hitting more than one astronaut would be greatly reduced.

If it's a sizable chunk of debris, the hole it'd make may well be far too large to patch, and even a small piece of debris may cause serious problems beyond a hull puncture. (If it hits a compressed gas tank, you might be hoping for a large puncture to let all the extra gas out and keep the station from literally bursting at the seams.) It's more likely to hit the main portion of the station than the capsule. The odds of hitting a given astronaut are the same no matter where they are, packing them in makes it more likely more than one will get hit if a hit occurs, but less likely any will get hit...all else being equal, it's a choice between minimizing odds of an incident and minimizing severity of the incident.

However, all else is not equal...the Soyuz capsule is right up against the station, and quite a bit smaller. If it's hit, the station stands a reasonably good chance of getting hit as well, while the Soyuz stands a much better chance of surviving if the station gets hit. It will also be a severe hazard to everyone in the area, regardless of whether they are in its direct path...it could shatter pressure vessels, breach piping and containers of chemicals, and send shrapnel flying in all directions.

So:
If they're in the Soyuz:
Most likely case, only the station is hit, and they have protection from shrapnel and concussion.
If the station and the Soyuz are both hit, they're screwed.
Least likely case: if the Soyuz is hit but the station is undamaged, they quite possibly all die.

If they're in the station:
Most likely case, only the station is hit, they have a high chance of injury or death even without being hit themselves, and will need to evacuate to the Soyuz.
If the station and the Soyuz are both hit, they're screwed.
Least likely case: if the Soyuz is hit but the station is undamaged, they survive.

It really comes down to "stay out of the bigger target".

nauthiz
2009-Mar-12, 06:22 PM
Does the safety protocol include any provisions for getting back out of the Soyuz capsule and plugging the hole if they're able to determine that the breach wasn't serious enough to require immediately abandoning the station?

novaderrik
2009-Mar-12, 11:04 PM
of course ABC news had a story about it that included a piece about how dangerous space travel is and whether the huge amount of money spent in space (i think less every year than just the special the "earmarks" that were put in the stimulus bill. that's as political as i'll get) could be better used elsewhere in this time of economic turmoil.

Sam5
2009-Mar-12, 11:35 PM
CNN just reported that it was a bolt, 5 inches long, traveling at 20,000 mph, passing about 3 miles away.

nauthiz
2009-Mar-13, 12:42 AM
Huh, that's a bit different from the estimate reported on Universe Today several hours ago. (0.35 inches)

slang
2009-Mar-13, 12:51 AM
Was that the best decision?

If the object were to hit Soyuz, wouldn’t it likely go through the bodies of multiple astronauts?

Soyuz: small target. ISS: big target. Yes, that was the best decision.


If it were to hit the station wouldn’t they want to make a effort to plug the holes before abandoning the ISS?

I may have missed where anyone said that ISS should be abandoned if it were to develop a leak. Surviving in Soyuz, donning a suit, and entering depressurized ISS to attempt plugging holes seems a smart scenario to me.

Damburger
2009-Mar-13, 08:09 AM
CNN just reported that it was a bolt, 5 inches long, traveling at 20,000 mph, passing about 3 miles away.

Guessing it would be about 1 inch in diameter and made of aluminium, so some rough calculations:

http://www.google.co.uk/search?q=(((5+inches+*+pi+*+(0.5+inches)^2)*(3000k g%2Fm^3))*(20000mph)^2)%2F2&btnG=Search&meta=

7.7MJ of kinetic energy, or to put it another way - 2 tonnes TNT equivalent

http://en.wikipedia.org/wiki/TNT_equivalent

No wonder NASA were concerned.

Jens
2009-Mar-13, 08:57 AM
Also, in this case, the thing had so much energy that it would have been catastrophic in any case. But with a smaller object, wouldn't the Soyuz capsule be better at withstanding a hit? After all, it's designed to reenter the atmosphere so I assume it would have better shielding than the ISS itself.

NEOWatcher
2009-Mar-13, 01:28 PM
CNN just reported that it was a bolt, 5 inches long, traveling at 20,000 mph, passing about 3 miles away.
I wonder if anyone is going to report what the collision speed would be. In other words what would be the angle of collision? (although not many angles would reduce the damage much)


Also, in this case, the thing had so much energy that it would have been catastrophic in any case. But with a smaller object, wouldn't the Soyuz capsule be better at withstanding a hit? After all, it's designed to reenter the atmosphere so I assume it would have better shielding than the ISS itself.
My guess is that shielding might actually make it worse in some cases. Thicker shielding may hold up better to an impact, but only up to a point. The stronger the shielding, the more you spread the impact. You may want the object to stay intact and just pass right through leaving just a hole. But; pressurization issues do complicate things.
The Soyuz is good because it's a much smaller target that can be isolated.

cjameshuff
2009-Mar-13, 05:17 PM
Also, in this case, the thing had so much energy that it would have been catastrophic in any case. But with a smaller object, wouldn't the Soyuz capsule be better at withstanding a hit? After all, it's designed to reenter the atmosphere so I assume it would have better shielding than the ISS itself.

Thicker walls, but less in the way of hypervelocity armoring. You use multi-layered armor with gaps between the layers (a simplified description, look up Whipple shielding). The projectile gets disrupted by outer layers and the jet of debris gets disrupted further by fill material, spreading it out so inner layers are more likely to stop it. It takes volume and mass and is an entirely different type of situation than the aerodynamic forces and radiant heating from the shockwave of reentry. I bet it'd be much more likely to withstand much larger and slower shrapnel, though.

joema
2009-Mar-13, 08:10 PM
Does anyone know the attitude of ISS vs the debris trajectory?

Soyuz is at one end of the assembly. If the object was closing at an acute angle from the other direction, that would place the entire ISS structure between the oncoming object and Soyuz.

Nasa frequently controls the shuttle attitude so the fuselage long axis is interposed against the highest threat debris probability. Maybe the move to Soyuz was for similar reasons.

publiusr
2009-Mar-13, 09:54 PM
The latest dope

The debris was from a PAM released by a Delta II upper stage. Delta II!
Ugh! Do I ever hate that crutch of a Goldin age sounding rocket!
http://en.wikipedia.org/wiki/File:Delta2_comparison_400.jpg

Remember how that debris from that lousy DC-10 (excuse me MD-11, whatever) brought down Concorde? Well the same thing almost happened to ISS.

I told you that the Delta pushers were up to no good. ;)

Ha ha..... Delta II! Oh this is just rich! Bomb disposal robots on Mars, Debris from an upper stage in Africa
http://www.saao.ac.za/public-info/pictures/debris-from-delta-ii/ http://fuse.pha.jhu.edu/users/reentry.html
http://www.reentrynews.com/2006047c.html
---and now this.

http://www.nasaspaceflight.com/2009/03/threat-to-iss-crew-soyuz/

SpaceCowboy
2009-Mar-13, 09:54 PM
In future years someone could probably make a killing if they could successfully remove space debris.

nauthiz
2009-Mar-13, 10:11 PM
What's wrong with Delta IIs? I did some looking online, and they seem to have a pretty solid track record. It appears to be better than the launch system that was used to get most of the ISS into orbit.

publiusr
2009-Mar-13, 10:16 PM
Tsyclon has it beat (R-7 too.) It puts two tons less in orbit than 50 yr old R-7. It's a crutch.

nauthiz
2009-Mar-13, 10:42 PM
I'm not sure I follow. If it's just about how much mass you can put in orbit, then there are quite a number of launch systems that have all three of them beat.

Damburger
2009-Mar-14, 10:44 AM
Remember how that debris from that lousy DC-10 (excuse me MD-11, whatever) brought down Concorde? Well the same thing almost happened to ISS.


It wasn't a DC-10... it was one of Xenus space cruisers! Scientologists were right all along!

Siguy
2009-Mar-14, 02:43 PM
The Delta-II is a great launch system, 141 launches have only led to two failures. There's a reason NASA prefers it for deep space missions.