Falling Spy Sat: Don't Panic
By Noah Shachtman EmailJanuary 29, 2008 | 9:40:39 PMCategories: Space
"Robert Connell" is the pseudonym for a former Air Force office who spent in nearly a decade in the service's space and missile corps. This is his first post for DANGER ROOM.
Everyone is freaking out, over this "spy satellite" that's re-entering the atmosphere. But the chances of there being any danger to people is pretty darn minuscule. 178 tracked objects re-entered the Earth's atmosphere last year. Of those, 27 were actual satellite payloads. The vast, vast majority of the time, these objects breakup in the atmosphere from the heat of re-entry and only very small fragments ever reach the ground.
However, occasionally intact pieces do survive re-entry and are found. Here's a picture of a Delta II rocket body which landed near Georgetown, TX in January 1997:
It's from “The Realities of Reentry Disposal,” a paper on the subject that's worth your while if you want to delve deeper into the subject.
The worst-case scenario is one where an object with radioactive materials re-enters. This happened back in January 1978 when the Russian COSMOS 954 satellite re-entered over Canada and left a radioactive debris field strewn across a (thankfully) sparsely populated area. But since then, a whole set of procedures have been put in place to cope with threats from above.
For everyone one of these objects, the military's Joint Space Operations Center (JSpOC) predicts where it will impact the ground and notifies military leadership and in turn civilian leadership. If it will impact over the United States or Canada, NORAD is notified along with FEMA and its Canadian equivalent. Risks are assessed and emergency plans are made if there is even the slightest chance of danger.
The Center also produces re-entry warnings for objects. These warnings, also called TIP Messages (Trajectory and Impact Prediction), start at about 4 days prior to impact and occur at set intervals. These are posted on the same website as the normal catalog data, and can be downloaded and viewed by anyone. You do need an account to get access but it is free and simple and anyone can do it.
There are a couple of caveats. First, only those objects which are large enough to be tracked by the US military's network of sensors have re-entry predictions. Usually this means objects bigger than 10 cm (about the size of a softball). Second, there are some objects that, as far as the US gov't is concerned, don't exist in the satellite catalog and therefore don't have re-entry notifications. This object that everyone is buzzing about happens to be one of those. Of course, anything the size of a school bus in low Earth orbit can be seen by anyone with a backyard telescope and some patience. Amateurs track many of the "black objects" and sometimes can produce locations. The best source of info is the See-Sat mailing list.
Here's a fun fact - the military operators that track and produce TIPs on all the normal space objects aren't allowed to know where the "spy satellites" are. They actually know less than the amateurs. The tracking and re-entry prediction for black satellites is handled by a completely separate unit. So don't go blaming the military guys about keeping this stuff secret, point the finger at the NRO people who insist on keeping secrets on objects that everyone can plainly see. The ironic part is that by keeping it a secret, everyone in the media (and every arm-chair "analyst)" is able to make up whatever they want about the object and thus it gets more well known than if it was a standard unclassified object.
Now the question is, should there be concern over this particular object? The answer is maybe, but probably not. Yes, it is re-entering in an uncontrolled manner when normally this type of satellite would be intentionally destroyed over the ocean far from prying eyes. The only reason that this particular object (and for that matter any satellite) would pose significant threat would be if it contained a radioactive power supply, such as the Snap series. There has been some discussion on the amateur mailing list over whether or not this satellite has such a power supply. Some have indicated that since solar panels can’t be seen it might indeed use one. Others have responded that since the satellite went into safe mode shortly after launch, the solar panels might not have deployed and that could be the reason for their absence. And in either case, there is evidence (and significant incentive) for the US to have secured any radioactive material within a protective shell that could survive re-entry, if only to keep the materials from falling into the wrong hands.
We can all be assured that the amateur observers will be tracking this object over the rest of its orbital life and providing the best indicators (and analysis) of when and where it might re-enter. The really sad part of this story is that the US government is withholding information on a potentially dangerous object in the name of national security, but that same information is readily available to anyone with a telescope, a trained mind, and a starry night to collect for themselves.