Sunday, December 27, 2009

NASA Plays Asteroids: Leapfroging to Mars?

Asteroids, the iconic video game of the early 1980s, marked its thirtieth anniversary last month. You can honor the occasion by shooting up some space rocks in the embedded player above or by playing on the official Atari Web site.

NASA recently dropped more than 1.2 billion quarters on its own version of the game with its Wide-field Infrared Survey Explorer. The space agency launched the $320 million orbiting observatory earlier this month in part to help identify previously unknown asteroids and comets, among other astronomical objects.

And if President Obama takes the advice of an advisory commission that looked at the space program's future, an even higher-stakes version of Atari's arcade classic could be in the works -- one that would involve sending astronauts on a mission to explore one of the nearby planetoids.

Hayabusa over asteroid ItokawaA number of robotic space probes have already paid visits to asteroids and other Near Earth Objects (or NEOs) in recent years. The image here shows the shadow of Japan's Hayabusa space probe as it passed over a half-kilometer-long, potato-shaped object called Itokawa in 2005 (click to enlarge). Hayabusa's seven-year mission is scheduled to end this coming June when it returns to Earth with a small sample from the asteroid's surface.

Space scientists have been eying asteroids as potential destinations for human explorers as well -- possibly as a more challenging alternative to the Moon missions envisioned for the end of the coming decade. October's brief suborbital test flight of a rocket intended to be a key component of NASA's future lunar expeditions gave the Moon plans an equally brief burst of attention. But so far Congress and the public just have not shown sustained interest in paying for what critics have dismissed as a been-there-done-that sequel to NASA's late-1960s lunar triumphs.

As the U.S. Human Space Flight Plans Committee noted in its final report this fall, the space agency won't be able to meet its 2020 time line for returning to the Moon with its current funding levels. The advisory panel offered the new administration several recommendations for moving forward, such as using new commercially developed spacecraft to ferry crews to and from the International Space Station after NASA retires its space shuttle fleet. That would free the agency to concentrate on human exploration instead. But exploration of what?

The main reason for going back to the Moon was to provide a stepping stone for an eventual trek to Mars. But an asteroid or some other object might be a more remote -- and more exciting -- destination, beyond the immediate gravitational neighborhood of the home planet. The technological, navigational and biological challenges of a months-long roundtrip journey would provide a better testing ground for an even lengthier Mars mission.

Others in the space community have been thinking along these lines for some time. The idea got a serious hearing during a high-level, two-day workshop on space exploration at Stanford University in February 2008. In a paper summarizing the discussion, the workshop's organizers said missions to near-Earth asteroids -- or perhaps the asteroid-like Martian moon Phobos -- would offer "valuable rewards in their own right, in addition to advancing the capability for sending astronauts on long interplanetary voyages. But their greatest value could be to supply what is missing in the current human space-exploration plan -- publicly engaging milestones on the road to Mars."

The International Academy of Astronautics (IAA) made a similar case for sending human crews to NEOs in a 2004 report. One scenario that report examined: mounting a two-month expedition in 2025 to the asteroid 1999 A010 -- a journey that would require a yearlong roundtrip. A mission like that would "stretch the capabilities of human exploration just enough to greatly reduce the risk of the Mars missions to come," the IAA said, and therefore "play an important architectural role as a bridge between Earth's neighborhood and Mars."

The IAA also pointed out that asteroids could quite literally help build that bridge by providing relatively easy access to valuable minerals for future space colonists. "Importing materials from Earth to space is very expensive, so a key to establishing a permanent human presence in the solar system is to find means to utilize resources found in space," the report said. Scouting missions would help determine whether rocky space islands offer opportunities "to develop in situ resources including the production of energy, fuel and construction materials."

"Because NEO's have very low gravity, transportation of these resources to other locations can be done relatively inexpensively, and thus they could be extremely useful in the development of a long-term human presence in space. Early human explorers at NEO's could complete resource assays begun by robotic missions, select the best locations for resource processing units, and initiate their operation. It may also be determined that NEO resources have commercial potential, in which case larger-scale processing operations requiring human presence may be appropriate."

And if the idea of space mines doesn't capture the imagination, there's always the doom-and-gloom angle: Passing asteroids pose threats to life on Earth, as the popular press enjoys reminding the public every time a NEO is projected to tumble into our vicinity. A 2007 NASA study ordered up by Congress looked at a variety of techniques for changing the course of a threatening asteroid or comet. It detailed all kinds of diversion techniques -- from nuclear options to "gravity tractors." The study also outlined various manned and unmanned opportunities for learning more about what the report called "Potentially Hazardous Objects," or PHOs. (It's a NASA study -- an abbreviation is required.)

So would any of those reasons be enough to reengage the public in making big investments in human space exploration during a time of war and economic distress?

We'll see if the White House and Congress are willing to line up their quarters for a multibillion-dollar round of Asteroids -- or whether other, more terrestrial games take precedence. In the mean time, Hollywood already has ideas for its own expensive version of Asteroids. Over the summer, blockbuster film producer Lorenzo di Bonaventura ("G.I. Joe," "Transformers") secured the film rights to Atari's arcade game. Tentative release date for Asteroids, the movie: 2012.

(Japanese space agency image of the Itokawa asteroid shown above from The Planetary Society.)

No comments: