Falling satellite debris doesn't have to be huge to be dangerous

"No, I don't thank you for the fish at all" (notindetroit)
11/14/2013 at 14:25 • Filed to: european sateillte, fallind debris, nuclear satellite

A few days ago, an aging European satellite !!!error: Indecipherable SUB-paragraph formatting!!! pretty much as predicted and pretty much as occurs all the time, !!!error: Indecipherable SUB-paragraph formatting!!! . !!!error: Indecipherable SUB-paragraph formatting!!! As the average artificial satellite is tiny (about the size of the average office desk up to an SUV - which is still pretty small if you think about it) it's truly astronomical that a large enough piece of debris is likely to cause damage. But that's not to say that debris, even when minuscule, can't be dangerous.

The above image (courtesy US Department of Energy via !!!error: Indecipherable SUB-paragraph formatting!!! ) is an illustration of an object commonly referred to as "Kosmos 954" (it's actual designation, as far as I can tell, is still classified). It was one of a series of satellites called "Upravlyaemy Sputnik Aktivnyj" or as we in the West call it, RORSAT (Radar Ocean Reconnaissance SATellite). As the name implies, they were meant to spy on NATO fleet movements. And, oh yeah, they were nuclear powered too.

On January 24, 1978, it re-entered Earth's atmosphere, and in the process, !!!error: Indecipherable SUB-paragraph formatting!!!

Needless to say it was a bit of a thorn in everybody's side at a time when the end of the world was a few keyturns and button pushes away. Our northern neighbors and the Soviets went back and forth as to who should pay for the clean-up (apparently the Russians only footed about half the bill) and there's still a question as to how effective the clean-up was, with some estimates claiming as little as 1% of the radioactive material recovered.

DISCUSSION (6)

Mosqvich > No, I don't thank you for the fish at all
11/14/2013 at 14:30

We tracked this stuff at the Air Force Space Command Command Center. They still do, but I moved on 6 years ago. It was a huge deal. I remember one reentry where it was going to hit smack in the middle of Minot, North Dakota. We were keenly watching. We didn't evacuate the town or anything because we knew the predictions were constantly changing. In this case, it hit the Atlantic ocean harmlessly. These are going to be "Lowflyers" by the way. They are in Low Earth Orbit. Satellites in Medium to Geo orbits are typically super-synched to where they won't reenter the Earth's atmosphere.

HammerheadFistpunch > No, I don't thank you for the fish at all
11/14/2013 at 14:35

Radioactive material has fallen from the skies before, these just with RTG's

The first one was a launch failure on 21 April 1964 in which the U.S. Transit-5BN-3 navigation satellite failed to achieve orbit and burnt up on re-entry north of Madagascar . [23] The 17,000 Ci (630 TBq) plutonium metal fuel in its SNAP -9a RTG was injected into the atmosphere over the Southern Hemisphere where it burnt up, and traces of plutonium-238 were detected in the area a few months later.

The second was the Nimbus B-1 weather satellite whose launch vehicle was deliberately destroyed shortly after launch on 21 May 1968 because of erratic trajectory. Launched from the Vandenberg Air Force Base , its SNAP-19 RTG containing relatively inert plutonium dioxide was recovered intact from the seabed in the Santa Barbara Channel five months later and no environmental contamination was detected. [24]

Two more were failures of Cosmos missions containing RTG-powered lunar rovers in 1969, both of which released radioactivity as they burned up.

The failure of the Apollo 13 mission in April 1970 meant that the Lunar Module reentered the atmosphere carrying an RTG and burnt up over Fiji . It carried a SNAP-27 RTG containing 44,500 Ci (1,650 TBq) of plutonium dioxide which survived reentry into the Earth's atmosphere intact, as it was designed to do, the trajectory being arranged so that it would plunge into 6–9 kilometers of water in the Tonga trench in the Pacific Ocean . The absence of plutonium-238 contamination in atmospheric and seawater sampling confirmed the assumption that the cask is intact on the seabed. The cask is expected to contain the fuel for at least 10 half-lives (i.e. 870 years). The US Department of Energy has conducted seawater tests and determined that the graphite casing, which was designed to withstand reentry, is stable and no release of plutonium should occur. Subsequent investigations have found no increase in the natural background radiation in the area. The Apollo 13 accident represents an extreme scenario because of the high re-entry velocities of the craft returning from cis-lunar space (the region between Earth's atmosphere and the Moon). This accident has served to validate the design of later-generation RTGs as highly safe.

For Sweden > Mosqvich
11/14/2013 at 14:42

Air Force Space Command Command Center

Ow my head.

Mosqvich > For Sweden
11/14/2013 at 15:15

My former Title:

Chief of Training, Standardization and Evaluation, Crew Commander, Headquarters Air Force Space Command Command Center.

Oy!

You can tell a Finn but you can't tell him much > Mosqvich
11/14/2013 at 17:07

They didn't go acronym happy on you and shorten it to CTSECCHAFSCCC?

You can tell a Finn but you can't tell him much > HammerheadFistpunch
11/14/2013 at 17:14

It sort of amazes me the high temperatures that graphite can handle. It's pure carbon which seems like it should burn easily. But they use it for everything from refractory linings to arc furnace electrodes to the Space Shuttle heat shielding on the wing leading edges.