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An Orion-derived spacecraft approaches an asteroid, with Earth in the distant background. (Paul DiMare)

The Million Mile Mission

A small band of believers urges NASA to take its next step—onto an asteroid.

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(Continued from page 1)

Shoemaker-Levy got more people inside and outside NASA thinking seriously about the danger of NEOs. In October 2001, astronaut Ed Lu and astrophysicist Piet Hut convened a one-day workshop in Houston with about 20 asteroid and propulsion experts to discuss the possibility of deflecting an incoming NEO. Out of that meeting the B612 Foundation was formed, named for the space rock on which author Antoine de St. Exupéry’s Little Prince lived. The stated goal of the organization, now headed by Apollo veteran Rusty Schweickart, is to significantly alter the orbit of an asteroid in a controlled manner by 2015, just to show that it can be done.

Not by astronauts, though.

“I’m an old astronaut, so I’m totally for manned flights to an asteroid,” says Schweickart, who was Apollo 9’s lunar module pilot. “But in terms of deflecting one, robotic missions are completely adequate and far more cost-effective.”

The B612 Foundation proposes a rendezvous with a space rock for weeks or months, during which the robot spacecraft would act as a “gravity tractor,” using its own minuscule gravitational pull to tug the asteroid onto a new course. While B612 spread its message, Ed Lu went on to spend six months aboard the International Space Station. Three months after his return to Earth, in January 2004, the Bush administration announced its Vision for Space Exploration, an ambitious call to send astronauts beyond Earth orbit for the first time since 1972. While NASA set up Constellation and began focusing on the lunar return, targeted for 2020, Lu and the Asteroid Underground quietly pondered other possibilities.

“When NASA unveiled the concepts of the Ares I and V launch vehicles and [the] Orion [crew capsule],” remembers Lu, “I started wondering, ‘Hey, we have these rockets at our disposal. What else can we do?’ ”

By the summer of 2006, Lu, Tom Jones, and Dave Korsmeyer, an engineer at NASA’s Ames Research Center who specializes in celestial mechanics, were conferring regularly with more than a dozen colleagues around the country, asking about the capabilities of Constellation and writing papers. NASA agreed to fund a feasibility study through its Advanced Projects Office that would examine how to use the Orion and Ares hardware to send people to a near-Earth asteroid. Korsmeyer managed the group. After many phone calls and e-mails among the 17 members of the study team, the first meeting took place at the Johnson Space Center in Houston in August 2006. Subsequent gatherings, about one per month, were convened at various NASA centers around the country. By the end of the year, the group had come to the conclusion that NASA’s new hardware could in fact carry humans to a NEO.

“The first part of this study was to determine if we could make it to an asteroid with no modifications whatsoever to Orion and the launch vehicle,” says Korsmeyer. “But that would be pretty hard and hairy.”

The weight of the crew, plus all the water, food, oxygen, and other supplies needed for a long voyage, posed a huge constraint. So the study team reduced the crew from four people (the baseline for a lunar mission) to three or even two, which freed up room for supplies. The good news is that a six-month asteroid mission wouldn’t require advanced systems for recycling water and air; Orion’s should be good enough.

The group also wrestled with the problem of communicating with a spacecraft more than two million miles from home. “At even a near-Earth asteroid, you’re 10 voice-seconds away,” says Korsmeyer. “You’re not really conversing with Earth at that point. The whole nature of the interaction becomes like the old ship-to-shore communications, a fancy telegraph, a voicemail. Not in real-time.”

An asteroid-bound crew would therefore need to “bring mission control on board,” says Korsmeyer, in the form of highly automated decision-making software. “When something bad happens, which tends to happen quickly, the crew and systems will have to manage it on their own. This is something humanity hasn’t done yet. But that makes it the best of all possible testing grounds for Mars, which, without an asteroid mission, will be like jumping into the deep end without practicing in the shallow end.” In comparison, “the moon is like the baby pool. I don’t mean to minimize that—Apollo 13 showed us you can drown there too.” But, he says, an asteroid “would really be someplace fabulously new. You’re talking 2.5 million miles, more than 10 times the distance between Earth and the moon. You’d be so far away you could cover up Earth with your finger. It would be no more than a beautiful, pale blue star.”

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