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March
20, 2009: On March 19th, astronauts onboard the International
Space Station checked themselves for microbes before stepping
outside on a space walk. It was a first-ever test of planetary
protection technology that, one day, could keep humans from
contaminating the sands of Mars.
"We
conducted the tests using LOCAD-PTS, a miniature biological
lab for space travelers," explains Jake Maule, principal
investigator for the experiment. LOCAD-PTS stands for Lab-On-A-Chip
Application Development Portable Test System.
Right:
An STS-119 spacewalker has his glove swabbed as he reenters
the ISS airlock on March 19, 2009. Credit: NASA TV. [video]
"Before
STS-119 crew members Steve Swanson and Richard Arnold exited
the International Space Station airlock to install the station's
new solar arrays, astronaut Sandy Magnus swabbed their gloves
with LOCAD's high-tech 'Q-tip' and then tested that Q-tip
for microbes. The procedure was repeated when the astronauts
re-entered the space station more than six hours later."
They
ran the test, called the LOCAD-PTS Exploration experiment,
because humans will one day exit a different airlock: on a
spaceship on Mars. And they'll need to be sure they're not
about to taint the Red Planet and its potential life forms
with human microorganisms. Explorers will be intent upon bringing
back pristine geological samples from Mars for analysis.
"This
experiment will show how to integrate quick bio-monitoring
tests of spacesuits into the very busy periods before and
after EVA, when procedures need to be streamlined and efficient,"
says Maule. "LOCAD is quick and easy, so it can be used
during those times without too much interference. It takes
only about 10 seconds to swab and 15 minutes to get the results."
To
lay the groundwork (literally) for the experiment, Maule and
Karissa West (from Charles River Laboratories, Inc) tested
15 sites all over the S6 truss (which bears the space station's
final set of solar arrays) during October and December 2008,
while it was in the Space Station Processing Facility at NASA's
Kennedy Space Center. They found little or no bacteria, but
they did find glucan, which is a marker for fungi, at some
of the 15 sites, especially on the fabric gap spanners that
span the distance between handrails on the truss.
"Fabrics
could be a significant source of biological contamination
on the Moon and Mars and are trickier to clean than smooth
metal surfaces," says Maule.
Because
astronauts can't yet take a LOCAD Q-tip outside the airlock
to sample individual sites on the truss as Maule and West
did on the ground, they tested the spacesuit gloves instead.
Members of the LOCAD team tracked the space walk, noting which
handrails and gap spanners the astronauts touched. "If
the crew comes into contact with a few of those gap spanners,
we expect to see higher LOCAD readings (for glucan) after
EVA," explains Maule.
Right:
Target swab sites on the astronauts' gloves. [Larger
image]
Eventually,
the LOCAD team plans to develop a special Q-tip to take outside.
For now, "our goal is to see if we can monitor the gloves
effectively without interfering with EVA preparation and cleanup.
Those very busy times on the ISS will be even busier before
a walk on the Moon or Mars."
Future
Mars explorers will need to monitor and restrict biological
contamination before, during, and after their outings. A spacecraft
containing humans always contains plenty of biological material,
and it can't all be eliminated. "Our experiment will
help define acceptable levels of biological material on the
surface of anything (including spacesuits) that might be taken
outside of the cabin and into 'the wild.'"
That
way if astronauts on Mars bring back anything from their outings
that looks lively under a microscope, they'll have some idea
whether it's (a) a native Martian life form or (b) a speck
of weird fungi from someone's navel.
Stay
tuned for results.
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Author: Dauna Coulter
| Editor: Dr.
Tony Phillips | Credit: Science@NASA
end
notes |
1.
LOCAD Personnel:
- Jake
Maule is the principal investigator for LOCAD-PTS
Exploration and LOCAD-PTS project scientist. He is
based at BAE Systems.
- Mike
Effinger of NASA's Marshall Space Flight Center (Huntsville,
Alabama) is the LOCAD project manager.
- Norm
Wainwright, principal investigator for LOCAD-PTS and
co-investigator for LOCAD Exploration, is also director
of research and development at Charles River Laboratories
in Charleston, SC.
- Suni
Williams and Dan Burbank, NASA astronauts based at
NASA's Johnson Space Center in Houston, Texas are
both co-investigators for LOCAD-PTS Exploration.
- Collaborators for this investigation
include Karissa West (Charles River Laboratories in
Charleston, SC), Amy Ross (EVA and Crew Survival Systems
Branch, NASA Johnson Space Center), Barbara Romig
(Crew and Thermal Systems Division, NASA Johnson Space
Center) and Joseph Kosmo (Crew and Thermal Systems
Division, NASA Johnson Space Center), and Scott Higginbotham
(NASA Kennedy Space Center).
LOCAD-PTS
Exploration is funded by NASA Science Mission Directorate’s
Moon and Mars Analog Mission Activities (MMAMA) Program
(POC: Jennifer Heldmann, NASA Headquarters).
2.
For the STS-119 mission, the space shuttle Discovery
is carrying the final set of solar array wings and truss
element that are needed to complete the station’s electricity
generating system.
3.
LOCAD can play a vital role in supporting both NASA's
goals to search for life and safeguard planetary protection.
Instruments such as Surface Analysis at Mars (SAM) --
an instrument on Mars Science Laboratory (MSL) -- which
detect trace amounts of organic molecules may be better
suited than LOCAD to search for life directly. Future
human expeditions to Mars may carry versions of these
instruments to the surface to search for life. LOCAD
could play an important role in monitoring the spread
of spacecraft-associated and Earth-derived biological
material (for example microbes in the cabin or on human
skin derived from the spacecraft, spacesuits, tools,
outflow from an airlock, spacecraft vents, etc.) that
could affect the results obtained by other instruments
on expeditions to Mars.
4.
See these websites for more information about LOCAD:
LOCAD
Home Page
LOCAD-PTS
Exploration Space Station page
LOCAD-PTS
Space Station Page
Space
Station Tricorder (Science@NASA)
Preventing
Sick Spaceships (Science@NASA)
Crabs
Give Blood for Space Travel (Science@NASA)
Astronauts
Swab the Deck (Science@NASA)
NASA's
Future: US
Space Exploration Policy |
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