February 2, 2004
Rovers Show
Off Bounce and Reach
NASA's two Mars Exploration Rovers are
using versatile robotic arms for positioning tools at selected
targets on the red planet, while a newly completed 360-degree
color panorama from Opportunity shows a trail of bounce marks
coming down the inner slope of the small crater where the spacecraft
came to rest when it landed on Mars nine days ago.
Airbag Marks Left by Opportunity
When it Landed
Click
for larger image
Courtesy NASA/JPL/Cornell
Opportunity extended its arm early today
for the first time since pre-launch testing. "This was a
great confirmation for the team," Joe Melko of NASA's Jet
Propulsion Laboratory said. Melko is mechanical systems engineer
for the arm, which is also called the instrument deployment device.
Mission controllers at JPL are telling
Opportunity to use two of the instruments on the arm overnight
tonight to examine a patch of soil in front of the rover. A microscope
on the arm will reveal structures as thin as a human hair and
a Mössbauer Spectrometer will collect information to identify
minerals in the soil, according to plans. Tomorrow, the rover
will be told to turn the turret at the end of the arm in order
to examine the same patch of soil with another instrument, the
alpha particle X-ray spectrometer, which reveals the chemical
elements in a target.
Spirit is now in good working order after
more than a week of computer-memory problems. It is brushing
dust off of a rock today with the rock abrasion tool on its robotic
arm. After the brushing, Spirit will use the microscope and two
spectrometers on the arm to examine the rock.
"We're moving forward with our science
on the rock Adirondack," JPL's Jennifer Trosper, Spirit
mission manager, said. Reformatting of Spirit's flash memory
was postponed from today to tomorrow. The reformatting is a precautionary
measure against recurrence of the problem that prevented Spirit
from dcommunicating properly last week.
Later this week, Spirit will grind the
surface off of a sample area on Adirondack with the rock abrasion
tool to inspect the rock's interior. After observations of Adirondack
are completed, the rover will begin rolling again. "We are
already strategizing how to drive far and fast," Trosper
said.
Observations by each rover's panoramic
camera help scientists choose where to drive and what to examine
with the instruments on each rover's arm. Dr. Jeff Johnson, a
rover science team member from the U.S. Geological Survey's Astrogeology
Team, Flagstaff, Ariz., said that 14 filters available on each
rover's panoramic camera allow the instrument to provide much
more information for identifying different types of rocks than
can be gleaned from color images such as the new panoramic view.
"By looking at the brightness values
in each of these wavelengths, we can start to get an idea of
the things we're interested in, especially to unravel the geological
history of these landing sites," Johnson said.
The main task for both rovers in coming
weeks and months is to find clues in rocks and soil about past
environmental conditions, particularly about whether the landing
areas were ever watery and possibly suitable for sustaining life.
Each martian day, or "sol" lasts
about 40 minutes longer than an Earth day. Spirit begins its
31st sol on Mars at 1:23 a.m. Tuesday, Pacific Standard Time.
Opportunity begins its 11th sol on Mars at 1:44 p.m. Tuesday,
PST. The two rovers are halfway around Mars from each other.
JPL, a division of the California Institute
of Technology in Pasadena, manages the Mars Exploration Rover
project for NASA's Office of Space Science, Washington, D.C.
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