On April 27, 2011, a Russian Progress M-10M rocket launched into space from Kazakhstan, carrying supplies for the astronauts aboard the International Space Station. It stayed docked to the ISS for nearly 181 days. On October 29, 2011 – last Saturday – it undocked,
empty, filled with a half a year’s worth of cast-off detritus. It performed a routine de-orbit burn, dropped down into the Earth’s atmosphere, and disintegrated as it burned up at 12:54 UTC.
But not before U.S. astronaut Mike Fossum took this incredible picture of it from space:
[Click to embiggen.]
That shot is amazing. You can see the pieces of the spacecraft falling off as it rams through the Earth’s air at Mach 25 or so. You’re probably seeing the solar panels, antennae, and various other external bits being stripped off and leaving their own meteoric trails.
In the case of resupply ships, the time and place they de-orbit is tightly controlled. In this case, as usual, it was sent into the Pacific. That’s generally safe because the ocean is 160+ million square kilometers in area, and much of that real estate is empty of islands.
As the pieces hit the air, they compress it violently, heating it up (it’s not actually friction that does the majority of heating, but this ram pressure that does it). They slow down after this initial stage to just a few hundred km/hr, then fall freely into the ocean. That’s still fast, but most impacts from space debris aren’t nearly as fast as most people think. This same thing happens to meteors as well, but they’re moving much faster as they come in from interplanetary space, blasting in at a minimum of 11 km/sec (7 miles/sec). But the principle is the same. In fact, the bits of rock or metal in a meteoroid (as the solid part of a meteor is called) slow down to free fall speeds so high up they have plenty of time to cool, and usually don’t hit the ground and cause fires. I’ve heard some reports of them having frost on them instead!
Anyway, this Progress de-orbit comes on the heels of the successful launch of a Progress craft aboard a Soyuz rocket, taking pressure off both NASA and the Russian space agency to get supplies and people to and from ISS. That’s good news for NASA, which could use some right now.
Image credit: NASA. Thanks to Ben H. in the comments for correcting my statement about the Progress being empty!