A few outlets in Britain are reporting a locally-designed space vehicle able to thwart asteroids that have destination Earth on their itineraries. They would get nudged off course just enough to miss. Two outlets that the Tracker sees covering this news also miss. The idea comes from the UK firm EADS Atrium (error note- misspelled that company on first try). Lost is an opportunity to explain in simple terms exactly how this thing would work. 

   The Telegraph‘s Richard Gray gets the essence down: The ten-tonne spacecraft would park itself about 50 yards (or meters, take your pick) from the hurtling rock a decade or two before its date with our planet. Its gravity would apply a teeny force on the asteroid. Oonches with its ion thrusters would prevent the two from merging. So this tiny dog would, on a feeble gravitational leash, slowly pull the asteroid off course. But where is the scale of forces to illustrate for readers how little it would take? One could calculate how much the probe would “weigh” on the asteroid, which is about the same as what its force on it would be as it hovers nearby. Gray has a good deal of general context. But, alas, the story says at one point that the “gravity tractor changes the angle it (the asteroid) is travelling in by a fraction of an inch over a period of 15 years…” The eyes glaze. The jaw drops. What kind of angle is measured in inches? Look, it almost imperceptibly changes the orbit’s vector by a cumulative fraction of a degree – and it would be worth knowing how large a fraction. That in turn would, on a path length of billions of miles of travel, subtend thousands of miles displacement after 20 years. Sure catastrophe become near miss. The real numbers ought to add up nicely and comprehensibly. Let’s see them, not jibberish about an angle of a fraction of an inch.

   The BBC has it, too, with similarly little detail - although no boners about the metrics of an angle. It also acknowledges that the general concept has been around for quite awhile.

Other Asteroid deflection news:

• Florida Today – John Kelly (blog): Asteroid Mission Getting Attention; This is the idea, in lieu of sending people back to the Moon or to Mars, to send a NASA crew to a passing asteroid and assess what kind of way to alter one’s trajectory might be most suitable.

NASA NEWS NOTE: The independent review panel that has spent month’s assessing the space agency’s abilities and budgets released its report today. The Tracker will attempt tomorrow morning a roundup on the expected, heavy coverage it will get over the course of the day.

-CP  

This entry was posted on Monday, August 31st, 2009 at 2:29 pm and is filed under Science Stories. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.