Bad Astronomy

Here we go again: ISS under threat of collision

No, this is not a repeat from a few days ago: NASA is tracking a piece of orbital debris that will pass uncomfortably close to the Space Station tonight. At 07:14 UT it’ll pass about 800 meters (about half a mile) from the ISS, much closer than last week’s 5 km (3 miles) miss.

This one is close enough that NASA is considering firing onboard jets to maneuver the ISS away from the debris. They’ll decide that by 20:00 (UT) tonight.

The Shuttle is on its way to the ISS but won’t be there until tomorrow, long after the danger has passed. Come to think of it, the best time to be threatened by debris is when the Shuttle is almost there. However, it’s not like the Shuttle can do much; the physics of orbital mechanics makes a daring rescue very unlikely. I doubt they have enough fuel on board to accelerate to the ISS, decelerate to match velocities, and do the deorbit burn to get back to Earth.

As usual, the best scenario is to avoid collision (the same is true for asteroid impacts). They’re tracking this, so we’ll see what happens.

Tip o’ the Whipple shield to Twitterers jcorradino, thenetruebix, and avinsen.