Mini-Sats: the Trick to Spying Earth-Bound Asteroids? Essay

934 Words May 1st, 2015 4 Pages
Go tiny or go home. That’s one suggestion for building telescopes to find a city-smashing asteroid before it finds us. Asteroids are space rocks, which can range from boulder sized up to chunks of rock nearly 1,000 kilometers (621 miles across). Most of them orbit between Mars and Jupiter. A fleet of pint-sized satellites orbiting the sun could track down the majority of asteroids that threaten Earth's safety. Or that’s what a team of scientists now proposes.

Others aren’t so sure. This plan has holes big enough to drive an asteroid through, some scientists charge.

The U.S. Congress directed NASA, the nation’s space agency, to identify 90 percent of all asteroids wider than 140 meters (roughly 460 feet). Congress set a deadline of
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Onboard computers can use special algorithms to process what the telescopes spy. This should help them to identify quickly moving asteroids. And the computers on these little systems can find fainter rocks than larger ground-based telescopes would typically turn up, Shao says.

Placing the mini-satellites far out in space makes up for some of what’s lost by their telescopes’ tiny size. Unlike on Earth, there’s no moon or weather to worry about. There’s also no atmosphere, which tends to blur images of space.

And moving the mini armada to a Venus-like orbit lets the fleet whip around the sun faster. That lets the satellites see more of the sky in less time than if they were near to Earth.

What the critics say
Saying CubeSats can do the work of a traditional space telescope for a tenth of the cost sounds too good to be true, says Eric Christensen. He’s an astronomer at the University of Arizona in Tucson. The idea of launching a quintuplet of mini space telescopes is “very interesting,” he says. Still, it could be hard for them to achieve what Shao's group claims.

Here’s one reason. Radio links would not be able to keep up with the rate of data being collected by the CubeSats, Christensen says. So any satellite outside Earth's orbit must do all image processing onboard — without human help. Christensen is also concerned about how the CubeSats would map out precise orbits of the asteroids they see.

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