Astronauts on asteroids? NASA toys with idea

Visualize this space
DigitalSpace, a privately held company based in Santa Cruz, California, has just released a design simulation of a notional crewed mission to an as-yet identified asteroid.

"This visualization is DigitalSpace's design concept for the mission, produced as an independent effort for the benefit of an internal NASA feasibility study completed in 2007," said Bruce Damer, founder of the company that provides leading edge Internet content and tools for communication, collaboration, and visualization.

The NASA study was performed to show that such a mission is possible with the new Constellation architecture, Damer said. DigitalSpace received input from numerous experts inside and outside NASA to produce the NEO mission visualization.

"It is important to note that this is not a NASA concept, nor has NASA given it any kind of technical blessing...it is a design created by the DigitalSpace team to stimulate discussion in the space community," Damer emphasized.

Indeed, many in the space community see any pilgrimage to an asteroid — by either robots or astronauts – as having multiple benefits.

Tooling up for NEOs
Learning about NEOs offers much in both scientific and practical terms. That's the perspective offered by Clark Chapman, a planetary scientist at the Southwest Research Institute's Department of Space Studies in neighboring Boulder, Colorado.

The reasons are many, Chapman said: Because there are many of them, because they are made of materials both common and exotic compared with materials available near the Earth's surface, and because they have negligible gravity...they are an obvious source of raw materials for future human exploration of outer space.

Tooling up for NEOs is already being tackled by specialists at Ball Aerospace & Technologies Corporation, also in Boulder. They have been looking into a small, low-cost landing probe design that could characterize both the surface and interior of small solar system objects, such as an asteroid.

The device is about the size of a basketball and weighs just a few pounds, said Dennis Ebbets, Senior Business Development Manager for Ball Aerospace's Space Science division. He and staff consultant, Richard Reinert, along with Rich Dissly, Ball's Deputy Director for Solar System Advanced Systems, suggest that several of the probes could be hauled to a target object and deployed individually.

Once released, these non-propulsive surface probes would freefall onto an asteroid's surface and begin transmitting results from their respective locales. The probes are outfitted with deployable panels to ensure self-righting to begin their errands.

Each self-energized probe might employ tiny imagers, accelerometers, x-ray spectrometers, sample collection and analysis gear — perhaps even utilize small explosive charges to create seismic waves that help gauge an asteroid's internal structure.

While asteroid surface probes could be deployed from an automated spacecraft, they are also a "perfect candidate" to be toted onboard a human expedition to a near-Earth object, Ebbets told Space.com.

Ebbets said asteroids deserve attention to help figure out what they are, where they come from, why they are different, and why there are families of these objects that are the same.

Additionally, "there's a non-zero chance of being hit by one of these things," Ebbets noted. He said he was a big fan of dropping a transponder onto an asteroid that's been branded as a potential troublemaker.

"Putting a transponder on it would be an excellent thing to do," Ebbets added. "You can get a very, very accurate orbit...predict years into the future whether it's on a collision course with us or not."

Long-delayed expectations
Along with the need to come to grips with scalawag asteroids that could harm Earth, SwRI's Chapman senses other NEO exploration outcomes.

"Though I am a space scientist strongly oriented toward the cost-effective robotic exploration of the solar system, I also grew up on science-fictional accounts of human expansion into the cosmos, and I endorse that more expensive — but ultimately inevitable — direction for human exploration," Chapman said.

Chapman said that it makes sense to him that NEOs could be used as "way-stations" to Mars. "Human visits to NEOs can go part-way toward understanding the challenges of going to Mars, yet not invoke the most serious challenges," he said.

Regarding concerns in some quarters that efforts to send humans to NEOs may be a distraction from the main, early focus of sending humans to the Moon, Chapman said: "In the current environment where the 'Vision' dominates NASA and the budget tends to restrict what we might do under the umbrella of the 'Vision' to the narrowest aspect of the 'Vision'...the focus must be on the Moon."

More than the Moon
But Chapman continued by noting that the dreams of people worldwide who want to expand their long-delayed expectations of going into interplanetary space, NASA — assisted by the budgetary processes in the Congress — must find a way to do more than just return to the Moon.

"I happen to believe that scientific exploration of the Moon...could be extremely significant. And the Moon is much more easily explored and developed than Mars, which must remain a longer term challenge. But NEOs offer a special, practical, and inspiring challenge that we should keep on the table," Chapman explained to Space.com.

In the context of the hazard of destructive impacts by NEOs on the Earth, Chapman said that "everything we can learn about the physical nature of NEOs can incrementally enhance our chances of dealing effectively with one, should one be discovered that seriously affects us." He explained that robotic exploration of such a NEO would be essentially as good as human exploration of that threatening object.

"But the generic exploration of NEOs — even if solely in the goal of getting to Mars — can have side benefits not only for understanding the range of issues we might have in dealing with a threatening NEO, but also in learning how we might mine the resources of NEOs for future use in human exploration of the solar system," Chapman concluded.

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