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NASA scientist defines mission to deflect asteroids and save the earth

By Layer 8 on Fri, 03/16/07 - 12:30pm.

KA-BOOM!If the idea of somehow deflecting a giant asteroid headed for earth smacks of a science fiction movie, you'd be right - it was called Armageddon.

And if you think NASA would like to make such a mission reality, you'd be right again. Despite testimony before congress last week that the space program's asteroid tracking program (yes they have one) is basically under budgeted for any new missions, one NASA scientist told a space conference this week how it might perform such a mission if it were able.

A NASA scientist has proposed using the using the replacement to the space shuttle, known as the Crew Exploration Vehicle to land on a near-Earth asteroid. The CEV is due to make its maiden flight in 2014, with the eventual aim of ferrying astronauts to and from the Moon.

Abell, who presented an outline of his mission concept at the Lunar and Planetary Science conference in Houston, Texas said the project is envisioned to include two or three crew members and last a total of 90-180 days. The crew would spend approximately 7-14 days at the asteroid. The plan would be to visit an asteroid in the sub-kilometer size range, perhaps about the size of asteroid Itokawa (535m) which was visited by Japan's Hayabusa spacecraft. At the moment, this would be the first time humans left the Earth-Moon system. In his published remarks Abell stated such a "CEV-type mission will have a much greater capability for science and exploration of NEOs than robotic spacecraft.

The main advantage of having piloted missions to a near earth object (NEO) is the flexibility of the crew to perform tasks and to adapt to situations in real time. Robotic spacecraft have only limited capability for scientific exploration, and may not be able to adapt as readily to certain conditions encountered at a particular NEO.

"The Hayabusa spacecraft encountered certain situations that were a challenge for both it and its ground controllers during close proximity operations at Itokawa. A human crew is able to perform tasks and react quickly in a micro-gravity environment, faster than any robotic spacecraft could (rapid yet delicate maneuvering has been a hall-mark of Apollo, Skylab, and shuttle operations)," he said.Abell's presentation comes on the heels of a NASA report to Congress entitled NASA Near-Earth Object Survey and Deflection Analysis of Alternatives that says it has neither the budget nor the equipment to properly search the skies for all sorts of similar NEOs.

NASA does carry out the "Spaceguard Survey" to find NEOs greater than 1 kilometer in diameter, and this program is currently budgeted at $4.1 million per year for FY 2006 through FY 2012. Some other key findings of that report included:

* The goal of the Survey Program should be modified to detect, track, catalogue, and characterize, by the end of 2020, 90% of all Potentially Hazardous Objects (PHOs) greater than 140 meters whose orbits pass within 0.05 Astronomical Unit (AU) of the Earth's orbit. (An AU, says NASA, is approximately the mean distance between the Earth and the Sun - or approximately 150 million km or 93 million miles).

* The Agency could achieve the specified goal of surveying for 90 percent of the potentially hazardous NEOs by the end of 2020 by partnering with other government agencies on potential future optical ground-based observatories and building a dedicated NEO survey asset assuming the partners' potential ground assets come online by 2010 and 2014, and a dedicated asset by 2015.

* New space-based infrared systems, combined with shared ground-based assets, could reduce the overall time to reach the 90 percent goal by at least three years. Space systems have additional benefits as well as costs and risks compared to ground-based alternatives.

* NASA's Dawn mission, expected to launch in June 2007, will increase our understanding of the two largest known main belt asteroids, Ceres and Vesta, between the planets Mars and Jupiter.

An editorial in the New York Times by Russell Schweickart, a former Apollo astronaut and chairman of the B612 Foundation, which promotes efforts to alter the orbits of asteroids, sums up the need for all the attention to asteroids: Americans who read the papers or watch Jay Leno have been aware for some time now that there is a slim but real possibility - about 1 in 45,000 - that an 850-foot-long asteroid called Apophis could strike Earth with catastrophic consequences on April 13, 2036.

What few probably realize is that there are thousands of other space objects that could hit us in the next century that could cause severe damage, if not total destruction.