[meteorite-list] Manned Missions to Near-Earth Objects Before Mars Proposed

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon, 30 Jul 2007 12:36:13 -0700 (PDT)
Message-ID: <200707301936.MAA25732_at_zagami.jpl.nasa.gov>

http://www.space.com/missionlaunches/070730_asteroid_probe.html

NASA Insiders Propose Stepping Stone Path to Deep Space
By Leonard David
spae.com
30 July 2007

GOLDEN, Colo. - NASA's Constellation Program - including the deployment
of the Orion crew vehicle replacing the space shuttle - will first be
assigned to International Space Station flights, then propel humans and
cargo to the Moon. Expeditionary missions to Mars and beyond will follow.

But there's ongoing discussion of mounting a piloted mission to an
asteroid - a voyage by astronauts to a near-Earth object, termed NEO for
short. These proponents feel certain of the scientific payoff from
reaching, first-hand, an asteroid - perhaps even becoming able to
exploit these chunks of celestial flotsam to further humankind's plunge
into the cosmos.

Space technologists argue that a NEO trip
could be a valuable shakeout of people, equipment, and procedures prior
to hurling astronauts beyond the Moon to the distant dunes of Mars.

For others, NEOs are viewed as downright dangerous, in terms of a
head-on collision between Earth and a space rock. It's best to get to
know these incoming beasts ahead of time.

NASA's NEOphytes

Internal looks by a small group of NASA "NEOphytes" have projected that
a human trek to one of those mini-worlds may involve two or three
astronauts on a 90 to 120-day spaceflight, including a week or two week
stay at the appointed asteroid.

Dispatching astronauts to a NEO is a sensible idea, said Harrison
Schmitt, Apollo 17 astronaut, geologist and current chair of the NASA
Advisory Council (NAC).

In fact, the Exploration and Space Operations subcommittees of the NAC
were briefed July 18 by NEO study team members from the NASA Johnson
Space Center, although there has been no Council action on the topic.

Schmitt told SPACE.com: "I think examination of a NEO mission and the
development of the stand-by monitoring systems, plans, protocols and
procedures for the diversion of a potentially Earth-impacting asteroid
would be very prudent activity for the U.S. to undertake."

Additionally, Schmitt said that a NEO mission would be a potentially
important demonstration of the versatility and capability of the
Constellation systems and a "gap-filler" before any Mars landing mission.

"So far, the arguments for asteroid science and resources are
interesting, but not well-developed or potentially as historically or
politically persuasive as a demonstration of long-term Earth defense,"
Schmitt said.

Extended flight

At this point in time, NASA has not issued any formal requirements to
augment the Orion spacecraft to
handle a piloted NEO mission, explained John Stevens, Director of
Business Development for the human spaceflight line of work at Lockheed
Martin Space Systems, near Denver, Colorado.

However, the company - builder of the crew-carrying Orion spacecraft -
internally funded two years worth of studies to flesh out technologies
to support a diversity of destinations, Stevens said. For sojourns to a
near-Earth asteroid, he said, future block upgrades to Orion are necessary.

"It's not that difficult from an architecture point of view to fly by an
asteroid and then come back," Stevens said. But pulling off a rendezvous
and docking with such an object, then rocketing back to Earth, requires
more propulsion oomph, he noted, along with the need for larger living
quarters for transiting crews, as well as recycling hardware to handle
oxygen and water needs.

Also, any roundtrip - Earth-to-NEO-to Earth - is an extended flight, way
beyond that required for Moon travel. So that brings up crew
psychological-sociological issues. "It's a concern...but we don't know
how much of a concern," Stevens advised.

Stevens said that the near-Earth object human mission can be viewed as
an intermediate step between a Moon mission and a Mars mission. "In
terms of complexity and the length of time that you have to stay
out...it does represent a good stepping stone between the kinds of
missions you do at the Moon and the kinds of missions that you next bite
off...which is the Mars mission," he said.

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 (SwRI) 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.
Received on Mon 30 Jul 2007 03:36:13 PM PDT