By now you've probably heard news reports about a super-secret spy satellite, designated USA 193, that will tumble uncontrolled from orbit within the next few weeks. The National Reconnaissance Office, which owns the doomed bird, has been mum on its mission and description.
But in a remarkable press conference on February 14th, a deputy national security adviser announced that President Bush has agreed to let the U.S. Navy try to destroy the satellite prior to its reentry by slamming a ship-fired SM-3 into it.
Apparently, DoD computer models have shown that, if left alone, more than half of USA 193's roughly 5,000-pound mass would survive the atmospheric plunge and reach the ground. In particular, there's a 20-inch diameter tank containing about a half ton of the highly toxic propellant hydrazine. So the decision was made to break up the satellite if possible.
You'll notice that I didn't say "shoot it down," as I've seen in many news reports. USA 193 isn't some aircraft that will simply drop from the sky if hit. Nor will some of the resulting fragments end up in long-lasting orbits that will threaten other spacecraft, as others have speculated.
None of the debris will survive more than a few weeks. That's because while, conceivably, the fragments' orbital apogees (high points) might end up somewhat higher, their perigees (low points) will not — and those perigees are already so low that fairly rapid decay is assured. All else being equal, breaking up the satellite will actually hasten reentry because virtually all the pieces will have higher area/mass ratios that the intact satellite did.
Whether this concern for public safety is genuine, or the NRO spooks don't want souvenir hunters combing through whatever wreckage might land on solid ground, or the Navy wants a good excuse for target practice isn't why I'm telling you all this.
Instead, I want you to go spot this satellite while you still can. The first interceptor missile won't be fired until sometime after February 20th. (There's some evidence that it'll come about 3:30 UT on the 21st, which coincidentally is during totality of that night's lunar eclipse.)
Until then, USA 193 will be left alone — and, as spy satellites go, it's easy to spot if you know where and when to look.
Right now the satellite's altitude is averaging just 163 miles (262 km), and it'll lose another 10% of altitude by the time the shooting starts. Because its orbit is inclined 58½° to the equator, USA 193 passes over virtually every city and town on Earth. If it were to pass directly over you after sunset or before sunrise, it might be as bright as a 1st-magnitude star. That should make it easy to spot with your eyes alone even from a light-polluted urban setting. Even better, right now the satellite is making a series of favorable early-evening passes over North America and Europe.
To determine where and when to look for it, you can get free predictions from our Satellite Tracker. After selecting your location and time zone, you'll be able to create predictions customized for your location. We utilize orbital parameters derived by Canadian satellite sleuth Ted Molczan from amateur sightings. Because the orbit is evolving rapidly, be forewarned that the predicted times might be off by a minute or two.
Good luck! If you succeed in spotting it, add a comment below to let me know how accurate the prediction was for your location.