Debris Narrowly Misses International Space Station

[Ben]

This article got me thinking -- what are they using on the space station to detect potential impact threats? It seems like simple radar would often not give sufficient warning given speed of objects and certain angles of attack. Looks like they had eight minutes to prep for this one, which seems like it would just give them enough time to get buttoned up in an escape capsule, but not enough time to suit up with O2. I also wonder when they would make the decision to hit the button to separate them from the ISS. Too soon and it may just be a near miss, too late and they might get caught in it.

A quick search showed me they use radar and "onboard debris collision sensors" but they don't go into detail on the latter.

http://beta.news.yahoo.com/crew-flees-space-station-avoid-incoming-junk-130806070.html

[birdman]

On-board radar would only work in a very small fraction (near-similar orbital planes/altitudes).  In a head-on, the closing velocity is 15.5km/s.  You would need a radar with range (against very small objects) of nearly 1000km to get even a minute of warning...more than 5-10 min, and you would be near the horizon.  Earthbound radars are used to track debris, then the orbital elements are propagated, and collision risk determined.  On-board sensors would need to be SBX size to really do anything (too big, easier to put on earth, after all, orbits are predictable) or yield far too little warning time.

[230RN]

 "'onboard debris collision sensors' but they don't go into detail on the latter."

Tricorders.

[Ben]

Earthbound radars are used to track debris, then the orbital elements are propagated, and collision risk determined. 

I'm just curious at how small of an object can be picked up. Seems like debris from an exploded object could disperse well create a pretty wide field, and also throw in some outlier pieces going every which way. I reckon a gallon paint can sized piece of steel could ruin your day in a head-on.

I've worked around radars that were outside my need-to-know and/or security level (other than, "don't fly within "X" of the antenna path if you ever want to have kids"), but it's hard to believe even a large array earthbound radar alone could pick up single, small objects that far away. If so, that's pretty amazing (and powerful).

[birdman]

I'm just curious at how small of an object can be picked up. Seems like debris from an exploded object could disperse well create a pretty wide field, and also throw in some outlier pieces going every which way. I reckon a gallon paint can sized piece of steel could ruin your day in a head-on.

I've worked around radars that were outside my need-to-know and/or security level (other than, "don't fly within "X" of the antenna path if you ever want to have kids"), but it's hard to believe even a large array earthbound radar alone could pick up single, small objects that far away. If so, that's pretty amazing (and powerful).

Small. But not small enough.  At that closing velocity, a 2 gram object (22LR bullet) has the same energy as 15 50cal rounds at the muzzle.  The ISS has meteoroid bumpers to take care of the little (sub gram size), bigger stuff (couple of cm) can be tracked and avoided (in theory, at least that is what they say)...it's the middle ground that is problematic.

But yes, space track radars are crazy...google some info on SBX as an example of what can be tracked.

[RoadKingLarry]

At what point would space "mining" become profitable for a private sector operation? Or, a private/public sector joint venture?

Some of that crap floating around up there is high dollar stuff.

There are actually quite a few private sector players in the game.
http://en.wikipedia.org/wiki/List_of_private_spaceflight_companies

[280plus]

 

"'onboard debris collision sensors' but they don't go into detail on the latter."

Tricorders.

Can't they just raise the shields?

[Ben]

"'onboard debris collision sensors' but they don't go into detail on the latter."

Tricorders.

Meh, I've got a tricorder on my Evo. I see no collision sensor option.

[Ben]

But yes, space track radars are crazy...google some info on SBX as an example of what can be tracked.

That SBX stuff is pretty cool. Great use for old drilling platforms. :)

[MillCreek]

^^^ It is currently parked at Harbor Island in Seattle undergoing an overhaul. 

[Fly320s]

^^^ It is currently parked at Harbor Island in Seattle undergoing an overhaul. 

Yes, and many locals seem to think it is ATC radar. If only they knew.