Satellite debris may be dangerous

February 20, 2008 7:06:20 PM PST
With the shuttle safely home, the Pentagon is now clear to shoot down a failing spy satellite.

It passed over the Bay Area moments ago, and a three-hour window opened for a missile launch, from a navy ship anchored west of Hawaii.

The rough weather is likely to scuttle the mission for Wednesday night, there are dangers of allowing the satellite to fall to earth.

This is the object that has caused all the commotion. A video of an errant U.S. spy satellite, shot by space hobbyist Paul Maley, as it passed above Texas last week.

"It's large enough to see with the naked eye," said Paul Maley.

Maley watched such objects since childhood.

Now as a member of the Johnson Space Center Astronomical Society, he predicts their paths and on a Web site, identifies whatever survives re-entry. Often, it's more than we might assume.

"Usually, these objects hit the Earth at 180 miles an hour, or less," said Maley.

That is why, when Columbia broke up in 2003, much of what landed across several states remained recognizable. It included a pressurized sphere, similar to one aboard the spy satellite.

So, when the government says it's worried about a tank with frozen poisonous hydrazine fuel, the argument has some merit.

But, in fifty years of space returns, hydrazine has never before been an issue.

"The hydrazine tank will survive intact. It is intact, the hydrazine which is in it, frozen, solid as it is right now, not all of it will melt," said NASA administrator Michael Griffin.

Critics have called this missile shot a convenient demonstration of anti-satellite capabilities.

Skeptics say it's all about keeping sensitive spy technology from falling into foreign hands. The government denies that.

"Once you go through the atmosphere and the heating and the burning that would not be an issue," said Vice-Chairman Joint Chiefs Gen. James Cartwright.

"It is certainly possible some of those fragments could land intact, or be recoverable," said Maley.

Assuming this missile hits its target, the pieces might take several days to reach earth -- the odds of hitting us.

"Historically, there is an account of a cow in Cuba being hit and killed, but no corroboration," said Maley.

You might wonder why they cannot predict the exact point of re-entry. Because the satellite is tumbling, and the upper atmosphere it expands and contracts.

We do know its path in space however. At about 6:06 p.m. on Tuesday night; that satellite passed over San Francisco -- if not for clouds, you might have seen it.