Spirit Update: ‘Stub Toes’ Won’t Stop Spirit
sol 74, Mar 19, 2004
the morning of Sol 74, which ended at 6:25 a.m. PST on March 19,
2004, by completing an alpha particle X-ray spectrometer integration
on the target "Panda," inside the scuff on "Serpent"
drift. Then Spirit placed the alpha particle X-ray spectrometer
back down on the target "Polar" for a 30-minute integration.
During that integration, Spirit took some images of disturbed soil
with the panoramic camera, and acquired some ground temperatures
with the miniature thermal emission spectrometer. Spirit then switched
the tools on its robotic arm to the Mössbauer spectrometer
for an hour-long integration on Polar. During that integration,
the rover took some sky and ground measurements with the mini thermal
emission spectrometer. Spirit finished its arm activities for the
day by acquiring three microscopic images of Polar and three more
image is the first-ever microscopic look inside a drift. It
captures only the scuffed interior of the Serpent drift and
is dominated by larger pea-shaped particles. These grains
are not natural to the inside the drift, but are crust particles
that have tumbled into the scuffed area as a result of the
digging. These grains lost their dust cover in the process
of falling into the scuff, giving scientists clues about the
strength – or lack of strength – of the bond between the dust
and sand particles.
interesting to scientists are the fine grains making up the
interior of Serpent drift. The grains of sand found within
drifts or dunes on Earth are usually about 200 micrometers
(.008 inches) in diameter — much like sand on a beach. On
Earth, dunes are formed when sand particles of this size are
bounced across a surface by wind and collect together as drifts.
Smaller particles, like the ones making up Serpent drift,
would not necessarily collect into a dune on Earth, but would
more likely be distributed across the surface like dust. The
fine grains making up the interior of Serpent drift are no
larger than 50 or 60 micrometers (.002 inches) and can be
compared to silt on Earth.
did this very fine material managed to accumulate into a drift?
Earth-based tests that simulate the wind speed and atmospheric
density of Mars have found it difficult to reproduce dunes
with grain particles as small as those found in the Serpent
drift. However, Earth-based tests cannot duplicate the gravity
of Mars, which is one-third that of the gravity on Earth.
This environmental factor is a likely contributor to the diminutive
material making up Serpent drift.
12:35 p.m. Mars Local Solar time, Spirit made a direct drive of
about six meters (19.7 feet) to another section of the Serpent
drift complex, called "Stub Toe." There the rover repeatedly
scuffed the drift and advanced .15 meters (half a foot) in a series
of five "scuff and drives." After the five scuffs and
advances were made, Spirit roved forward another 3 meters (9.8
feet) and then looked back over its shoulder using the mini thermal
emission spectrometer and navigation cameras to analyze the damage.
The rover continued along the Bonneville crater rim with a 16-meter
direct drive, and then an auto-navigation drive for 9 meters (29.5
feet). Spirit completed a final set of drives to set up for a
touch and go on sol 75 at around 2:10 p.m. Mars Local Solar time.
The total amount of driving for sol 74 was an impressive 34.3
meters (112.5 feet).
took navigation camera and panoramic camera images of the drive
directions for planning the sol 75 traverse. The rover acquired
some mini thermal emission spectrometer reconnaissance images
and then took a 30-minute siesta before the afternoon Odyssey
relay pass. During that pass, Spirit used the mini thermal emission
spectrometer to acquire a sky profile and ground temperature observations.
On sol 75,
which will end at 7:05 a.m. PST on March 20, 2004, Spirit will
place the microscopic imager on a soil target and drive about
22 meters (72.2 feet) around the Bonneville crater rim. Spirit
will also conduct atmospheric observations with the mini thermal
emission spectrometer and panoramic camera.
* * * * * * * * *
Update: Steering to ‘Serpent’
71, Mar 16, 2004
drift dubbed "Serpent" stretches in front of NASA’s
Mars Exploration Rover Spirit in this picture from the left
eye of Spirit’s front hazard-avoidance camera. Spirit took
the image during its 71st martian day, or sol, on Mars (March
15, 2004) while exploring the rim of the crater nicknamed
"Bonneville." The following sol, the rover used
its wheels to dig into the drift and expose material under
sol 71, which ended at 4:26 a.m. PST March 16, 2004, with a morning
nap to re-charge after the record-breaking number of activities
it accomplished on sol 70. After that, it was back to work. Spirit
began by retracting the alpha particle X-ray spectrometer, closing
the doors, and imaging the doors with the front hazard avoidance
cameras to confirm that they were closed. Spirit then proceeded
to observe a soil target with the microscopic imager, and it also
used the panoramic camera to observe the magnets, do a sky survey
and capture a dust devil movie.
Then it was time to drive. Spirit completed a
15-meter (49.2 feet) blind drive followed by a 3-meter (9.8 feet)
auto-navigation drive around the south rim of "Bonneville"
crater toward a drift named "Serpent." Once there, Spirit
completed post-drive science observations and a miniature thermal
emission spectrometer study of the atmosphere, ground and future
objective on sol 72, which ends at 5:06 a.m. PST March 17, 2004,
will be to disturb and analyze the material at Serpent. Spirit
will drive over the dune and back up to an optimal observation
position. It will then analyze the area with the panoramic camera
and mini thermal emission spectrometer. Spirit will end the sol
by driving back on top of the dune.
Update: Try Again to Exit Crater
sol 56, Mar 21, 2004
tried driving uphill out of its landing-site crater during its
56th sol, ending at 10:05 p.m. March 21, PST, but slippage prevented
success. The rover is healthy, and it later completed a turn to
the right and a short drive along the crater’s inner slope. Controllers
plan to send it on a different route for exiting the crater on
sol 56, Opportunity successfully examined a patch of soil dubbed
"Brian’s Choice" with its Moessbauer spectrometer, alpha
particle X-ray spectrometer and microscopic imager. Following
the drive, it made observations with its navigation camera and
miniature thermal emission spectrometer. Wake-up music for the
sol was "Fly Like an Eagle," by the Steve Miller Band.
* * * * * * * * *
Update: Finishing up at the Outcrop
50, Mar 15, 2004
"Carousel," the rock in this image was the target
of the Mars Exploration Rover Opportunity science team’s outcrop
"scuff test." The image on the left, taken by the
rover’s navigation camera on sol 48 of the mission (March
12, 2004), shows the rock pre-scuff. On sol 51 (March 15,
2004), Opportunity slowly rotated its left front wheel on
the rock, abrading it in the same way that geology students
use a scratch test to determine the hardness of minerals.
The image on the right, taken by the rover’s navigation camera
on sol 51, shows the rock post-scuff. In this image, it is
apparent that Opportunity scratched the surface of "Carousel"
and deposited dirt that it was carrying in its wheel rims.
University (St. Louis) / Cornell
On sol 50,
which ended at 4:08 p.m. PST on March 15, Opportunity got closer
to completing its observations of the rock outcrop. The rover
arm, with the alpha particle X-ray spectrometer at the ready,
was placed on the rock called "Shark’s Tooth" for a
30-minute observation. The microscopic imager then took a series
of pictures of the targets "Enamel 1" and "Lamination."
The focus then switched back to "Shark’s Tooth" for
an examination by the Mössbauer spectrometer.
The song chosen
to awaken Opportunity was "The Dentist" by Bill Cosby,
in honor of the toothy targets in "Shark’s Cage."
The sol also
included many panoramic camera observations of targets with creative
names like "Patio Rug," "Anaconda Snake Den,"
"West Zen Garden" and "Garter Snake."
The next sol
calls for a final experiment at the outcrop called "scuffing."
"Scuffing" essentially turns one of the rover wheels
into a tool to scrape a rock to help determine its hardness. The
rock "Carousel" will be scraped by Opportunity’s front
left wheel. After that experiment, the rover will begin its trans-crater
traverse to five soil survey targets, the first of which will
lead Opportunity up the sandy southern face of the crater.