BOULDER, Colo. – Call it Operation: Plymouth Rock. A plan to
send a crew of astronauts to an asteroid is gaining momentum, both within NASA
and industry circles.
Not only would the deep space sojourn shake out hardware, it
would also build confidence in long-duration
stints at the moon and Mars. At the same time, the trek would sharpen
skills to deal with a future space rock found on a collision
course with Earth.
In Lockheed Martin briefing charts, the mission has been
dubbed "Plymouth Rock – An Early Human Asteroid Mission Using Orion." Lockheed
is the builder of NASA's Orion
spacecraft, the capsule-based replacement for the space shuttle.
Study teams are now readying high-level briefings for NASA
leaders - perhaps as early as this week - on a pilgrimage to an asteroid, along
with appraisals of anchoring large, astronaut-enabled telescopes far from
Earth, a human precursor mission to the vicinity of Mars, as well as an
initiative to power-beam energy from space to Earth.
The briefings have been spurred in response to the recent
Review of U.S. Human Spaceflight Plans Committee and the option of a "Flexible
Path" to human exploration beyond low-Earth orbit.
On this path, the committee suggested, humans would visit
sites never visited before and extend U.S. savvy in how to operate in space -
while traversing greater and greater distances from Earth.
Building momentum
The merits of a human mission to a Near Earth Object (NEO)
were detailed here Nov. 18 during a two-day meeting of the Small Bodies
Assessment Group, SBAG for short.
SBAG was established by NASA in 2008 to identify scientific
priorities and opportunities for the exploration of asteroids, comets,
interplanetary dust, small satellites, and Trans-Neptunian Objects. The group
also provides scientific input on the utility of asteroids and comets in
support of human space activities.
The new studies are viewed as an iterative process - to be
weighed both by NASA and the White House, said Paul Abell, a research scientist
at the Planetary Science Institute detailed to the space agency's Johnson Space
Center in Houston, Texas and working in the Astromaterials Research and Exploration
Science Directorate. "It's going to take a bit of time. I don't think there's
going to be a quick decision."
How the White House will react to a human trek to an
asteroid is beyond anybody's crystal ball. However, undertaking the effort has
garnered the attention of Lockheed Martin - builder of the space shuttle
replacement - the Orion spacecraft.
Asteroid-bound Orion
The Plymouth Rock mission study began a couple years ago,
said Josh Hopkins, in the advanced programs for human space flight division at
Lockheed Martin Space Systems Company in Denver, Colo.
"We have been looking at what other interesting science
missions could be done with Orion...and asteroids were one of the ideas that
percolated to the top," Hopkins told the SBAG attendees. He made it clear that
the firm's study was done using corporate funds and doesn't imply that NASA has
endorsed company results.
Initial looks at the NEO venture involve the coupling of
two Orion spacecraft.
In this situation, a two-person Orion would link up with an
unpiloted sister craft that's loaded with extra fuel, food, water, and oxygen.
It would be tossed into orbit - as well as an Earth departure stage - by NASA's
planned Ares V heavy-lift booster.
Bridging the moon and Mars
While detailed NASA and industry looks at the makings of a
NEO mission are still in play - including use of inflatable modules to add crew
volume - "it's an attractive option," Hopkins said. "It's really a good
middle-step between the moon and Mars."
However, maximizing astronaut safety, dealing with such
things as trash management, cosmic rays, sketching out abort scenarios must
still be addressed, Hopkins noted. But given the core attributes already built
into the Orion system "we think it does make sense for the human spaceflight
program to be investigating this," he said.
Between NASA and industry looks, the flight of astronauts to
a NEO could occur in the 2020 to 2025 time period. The round-trip mission would
take some six months.
There would be no landing
on the asteroid. Rather, they would park in close proximity, then jet
backpack onto the object. Once there, science gear would be deployed as samples
of the space rock are gathered – on the order of a couple hundred pounds (100
kilograms).
"We assume staying at the asteroid for five days. They could
stay a week or two. But staying for a month gets hard," Hopkins explained.
While on duty, astronauts would engage in gathering data useful to understand
the internal makeup of the asteroid. That, in turn, is solidly helpful, he
added, in dealing with harmful space rocks on a worrisome trajectory dangerous
to Earth.
Today, there are a handful of candidate asteroids that could
be visited a couple decades from now, said Clark Chapman, an asteroid expert at
Southwest Research Institute here in Boulder. That number will grow as more
ground and space-based instruments come on-line, surely increasing the
discovery rate of NEOs, he stated.
"We'd really like a larger pool of candidate targets so that
we could visit a NEO that has cool properties and would have the greatest
scientific return," Chapman told SPACE.com.
Profound impact
"Human exploration is for human purposes," said Mark Sykes,
chair of the Small Bodies Assessment Group. He is also director of the
Planetary Science Institute in Tucson, Ariz .
Science by itself doesn't drive human exploration, Sykes
noted, "but we can benefit, scientifically, from this. We'll take advantage of
whatever opportunities come our way!"
Sykes said that he had briefed the committee that conducted
the recent review of U.S. human spaceflight plans.
Specifically, Sykes said that he underscored the prospect
that NEOs represent a location of resources that could have a profound impact
on expanding sustainable human operations beyond low Earth orbit. They could be
a well spring of water, he added, as well as useful for life support and
radiation shielding.
If so, asteroids may well act as a lynch pin for people
living, working and populating space, Sykes suggested. But are those resources
recoverable in an economic way?
"It's within the realm of consideration. Of course, a lot
more homework needs to be done," Sykes stressed.
Leonard David has been reporting on the space industry
for more than five decades. He is past editor-in-chief of the National Space
Society's Ad Astra and Space World magazines and has written for SPACE.com
since 1999.
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