[meteorite-list] NASA Considering Sending Astronauts To An Asteroid

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 22 Mar 2007 14:10:18 -0700 (PDT)
Message-ID: <200703222110.l2MLAIO25671_at_zagami.jpl.nasa.gov>

http://space.newscientist.com/article/mg19325964.700-now-fly-me-to-the-asteroids-as-well.html

Now fly me to the asteroids as well
David Shiga
New Scientist
22 March 2007

They are still a long way from returning to the moon, but NASA is
already thinking about sending astronauts to an asteroid. Such a mission
could be accomplished using the same spacecraft and launch vehicle being
designed to take Americans back to the moon.

"This would be the first time that humans go outside of the Earth-moon
system," says Paul Abell of NASA's Johnson Space Center in Houston, Texas.

About two years ago, NASA started work on a new crew capsule and rocket
to send astronauts to the moon by 2020 (New Scientist, 11 August 2005, p
6). Now, Abell and his team say that the Orion capsule and Ares rocket
could also take humans to one of the many asteroids with orbits that
bring them near Earth.

The team's analysis shows that the mission would require less fuel than
going to the moon, because the vastly weaker gravity of an asteroid
means hardly any effort is needed to escape its tug on the way back.
Also, because of the weaker gravity, Orion would be able to simply hover
close to the asteroid, and thus dispense with a lander, making for a
lighter mission overall.

A round trip to a 30-metre asteroid called 1998 KY26, for example, which
will pass by Earth in 2013 and 2024, could be completed in three months.
However, 1998 KY26's relatively rapid spin may make it an undesirable
candidate. The team expects that ongoing asteroid searches will identify
more suitable targets.

Besides studying the structural properties of the asteroid using radar
sounding - important if we ever needed to deflect such an asteroid - the
mission would serve as a testing ground for a mission to Mars. It would
be a "baby step towards Mars", says team member Robert Landis, adding
that going to an asteroid is not meant to replace going back to the moon.

Any asteroid mission faces two major challenges. One is ensuring there
is enough water, oxygen and food to sustain the crew on such a long
mission. The lunar version of Orion is designed to carry enough supplies
to support a crew of four for two weeks. Abell's team believes that the
spacecraft can be reconfigured to carry just two or three, increasing
the weight that can be used for supplies.

The second issue is the radiation hazard from cosmic rays and solar
flares, which can put astronauts at increased risk of developing cancer.
"I see no easy way to mitigate the problem on this mission except to
make the duration as short as possible," says David Smith of the Lunar
and Planetary Institute in Houston, Texas, who is not part of the team.
The astronauts might just have to accept the increased risk, he says.

Landis says the crew's water supply could be used as a shield against
the radiation, and that their waste could be saved for the same purpose,
but the team admits that radiation remains a challenge. "It's one of the
issues we'll have to address," Abell says.

Abell presented the idea at last week's Lunar and Planetary Science
Conference in Houston, Texas.

>From issue 2596 of New Scientist magazine, 22 March 2007, page 14
Received on Thu 22 Mar 2007 05:10:18 PM PDT