TCS - TU Mars Pathfinder

TU Mars Pathfinder

From the September 1997 issue of the I/O Port Newsletter

TU Hosts Mirror, Chat Site for NASA Mars Pathfinder

As of 6:00pm Tuesday night, July 15, The University of Tulsa, entered into an informal partnership with NASA's Jet Propulsion Laboratory to host a mirror of the JPL Mars Pathfinder Web Site. Due to the unprecedented demand (over 100,000,000 hits per day) for access to the Mars web site, NASA has partnered with 26 International and National corporations and higher education institutions to make this site accessible and speedy. The TU Mars Pathfinder mirror site can be found at: http://mars.jpl.utulsa.edu

The TU/NASA JPL Site is updated automatically with the latest content direct from NASA every 15 minutes. Full copies of movies, animations, virtual reality walkthroughs, images, and information are now housed at TU.

As an added benefit, we have set up a live chat/messaging center online called the "Mars Pathfinder Message Center" It's our sincere hope that once this site is advertised and possibly sanctioned by NASA, we will be able to host forums for the general public to interact with the Pathfinder Team. Of noted interest to us is the ability to converse online with K-12 Educators. Please help us publicize this site: http://mars.jpl.utulsa.edu/chat

(Note: Existing users of the TU "Campus Chat" WebBoard can login using their existing Username and Password)

For more information, please contact Sean Alexander, University Webmaster at webmaster@utulsa.edu

Click image to enlarge

This 360-degree photomosaic was taken by the IMP camera on July 4, 1997. The foreground is dominated by the lander, newly entitled the Sagan Memorial Station. All three petals have been fully deployed. Upon one of the petals is the Sojourner microrover in its stowed position. The metallic cylinders at either end of Sojourner are the rover deployment ramps. Visible at the rear end (right) of the rover is the Alpha Proton X-Ray Spectrometer. Located to the right of the center petal is a dark, circular object and a bright, metallic object. Both are components of the high gain antenna. The black post, bull's-eye rings, and small shaded blocks in the far right portion of the image are components of the calibration targets.

Terrain of Ares Vallis is in the background. The sections of soil and the large rocks surrounding the Sagan Memorial Station will provide the rover with numerous opportunities to employ the Alpha Proton X-Ray Spectrometer. The prominent hills in the background will aid scientists in determining the exact site of the Sagan Memorial Station.


This image shows the Sojurner Rover conducting its examination of "Barnacle Bill" with the APXS. The images was taken by the fully deployed (1.8 meters) IMP camera.

Click image to enlarge

This 360 degree "monster" panorama was taken by the deployed Imager for Mars Pathfinder (IMP) on Sol 3. All three petals, the perimeter of the deflated airbags, deployed rover Sojourner, forward and backward ramps and prominent surface features are visible. The IMP stands 1.8 meters over the Martian sufrace. The curvature and misalignment of several sections are due to image parallax.


Sojourner has made contact with the rock Yogi in this image, taken with the Imager for Mars Pathfinder (IMP) at 8:45 p.m. PDT on Sol 6. The rover's left rear wheel has driven up onto the Yogi's surface in an attempt to get as close as possible to the rock's surface. Sojourner will later use its Alpha Proton X-Ray Spectrometer (APXS) instrument to conduct a study of Yogi's chemical composition.

MISSION STATUS - 15 July 1997, 12:00 noon PDT

The Mars Pathfinder flight team today reported on a very successful night of data transmission, receiving an unprecedented 90 megabits of data on the chemical makeup of a boulder nicknamed Yogi, atmospheric measurements and nearly all remaining portions of a 360-degree color panorama image of the landing site.

Last night's downlink sessions contained detailed information on the chemistry of Yogi taken by the rover after a second attempt to position its alpha proton X-ray spectrometer against the rock. The new data also included measurements of the aerosol content of the Martian atmosphere, which was used in parallel with new Hubble Space Telescope images of Mars to characterize changes in regional and global weather patterns in the last three weeks.

Recent incidents in which the Pathfinder lander's computer reset itself were discussed by Glenn Reeves, flight software team leader. According to Reeves, computer resets have occurred a total of four times during the mission -- on July 5, 10, 11 and 14. The flight team has attempted to avoid future resets by instructing the computer to handle one activity at a time --"serializing" activities -- rather than juggling a number of activities at once.

The team continues to troubleshoot the problem by testing all of the sequences leading up to reset in JPL's Mars Pathfinder testbed; considering changes in the flight software that would allow for immediate recovery if the flight computer were to reset itself; and modifying operational activities to minimize data loss if a reset should occur again. "In a sense, the reset itself is not harmful because it brings us back into a safe state," said Reeves. "But it does cause a disruption of the operational activities."

Among the science highlights, the Pathfinder mineralogy team presented new information about Barnacle Bill, a very roughly textured rock, and Yogi, a much larger boulder nearby, which was successfully measured last night.

Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, "having not gone through the cooking that Barnacle Bill and other andesites have gone through," said Dr. James Greenwood, University of Tennessee, a member of the mineralogy science team. Although these observations are very preliminary, Yogi appeared to be more like the common basalts found on Earth. The next rock to be studied is "Scooby Doo," followed by others, including "Half Dome," "Wedge," "Shark" and "Flat Top," all located in a different region of the landing site. Some are near the lander petal on which Sojourner flew to Mars.

Observations from the Earth-orbiting Hubble Space Telescope revealed a lot of surface-atmospheric transport activity. A dust storm detected in Vallis Marineris just prior to Pathfinder's landing, for instance, had all but vanished within two weeks according to new Hubble images, noted Dr. Steven Lee, University of Colorado, a Hubble investigator. Some of the dust from that regional storm had diffused to the Pathfinder landing site, which was consistent with recent Pathfinder atmospheric opacity measurements.

In observations taken between May 18 and July 11, the amount of dust near the Pathfinder landing site had nearly tripled. "There's obviously a lot of very rapid transport going on here, with some of the dust diffusing toward the landing area," Lee said. "This is consistent with Pathfinder observations on the surface."

The increase in atmospheric dust appears to be diminishing the amount of cloudiness, Lee added. Clouds observed near the southern polar hood had begun to decrease in the most recent Hubble images as the dust diffused throughout the southern hemisphere. The Hubble team estimated that these clouds were relatively low, hovering around 15 to 16 kilometers (9 to 10 miles) above the surface, because the tips of some Martian volcanoes could be seen peeking through the cloud tops.

On Pathfinder's 11th Martian day -- or Sol 11 -- Earth rise at the Martian landing site was at 4:07 p.m. Pacific Daylight Time on Monday, July 14, followed by sunrise at 7:16 p.m. PDT. The flight team radioed commands to the Pathfinder lander beginning at 7:40 p.m. PDT. Data were downlinked from Pathfinder's lander from 9:02 to 9:35 p.m. PDT using the lander's low-gain antenna; this session included the spectrometer data on Yogi. A second downlink session, on the lander's high-gain antenna, began at 1:20 a.m. and ran until 5:10 a.m. PDT, with a half-hour break in the middle while the antenna was adjusted; this session included the new portions of the color panorama image. Earth set was at 5:46 a.m. and sunset was at 8:15 a.m. PDT.



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Tulsa Computer Society 08/15/97
Don Singleton, President
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