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Mars Pathfinder Mission Status
July 6, 1997
9 p.m. Pacific Daylight Time
With a perfectly healthy lander and rover on the surface of Mars, scientists on the Mars Pathfinder team burned the midnight oil last night to design their first day of activities for the robust, 23-pound rover named Sojourner Truth.

The rover spent its first night on Mars very near the end of the rear ramp from which it exited the lander last night, taking measurements of the Martian soil with its alpha proton X-ray spectrometer. At 3:45 p.m. PDT today, the operations team at JPL "woke up" the rover by playing "Final Frontier," the theme song from the television program "Mad About You," in keeping with the traditional wake-up songs used to arouse the astronauts during space shuttle missions.

Two experiments for Sol 3 were radiated to Pathfinder earlier today. The first is a soil mechanics experiment, in which the rover will lock five of its wheels, then turn the sixth wheel in both directions. Scientists will observe the depth of the wheel tracks and the movement of a top layer of fine-grain material. The second experiment will send Sojourner to its first rock, nicknamed "Barnacle Bill," for its very rough, barnacle- like surface.

This traverse to Barnacle Bill will involve two maneuvers for the rover: the first to turn its wheels approximately 70 degrees in the direction of the rock; the second maneuver to move backward with its fully deployed spectrometer until it touches the rock. The rover will travel approximately 36 centimeters (1.2 feet) to reach the rock. Once the spectrometer has been placed against Barnacle Bill, Sojourner will spend the night gathering data on its composition.

"With any luck, we will get a picture of Sojourner holding hands with Barnacle Bill," said Brian Muirhead, deputy project manager, at a 6 p.m. press briefing.

Among the most anticipated data expected to be returned tonight are 12-color, high resolution images that will be pieced together like a mosaic to create a 360-degree, color panorama, or "monster pan," of the landing site. The color variations and higher resolution will help scientists identify more geological features worthy of exploration in this very rocky flood plain. The first picture of the Pathfinder lander taken by the rover is also expected to be returned tonight.

Scientists pointed out other interesting rocks, soil deposits and features on the horizon in this evening's press briefing. A pair of mountain peaks, nicknamed "Twin Peaks," revealed ribbons of different colored rock. Scientists noted that the horizontal bands could be sedimentary layers or terraces cut by erosion. Angular rocks appearing in the foreground, all leaning in the same direction, suggest they were ejected from a nearby impact crater. A variety of smooth round rocks suggested that they were transported by water in Mars' early evolution.

"In the initial analysis of these images, we see multiple episodes of flooding, not just one catastrophic event, but many," said Dr. Ronald Greeley, of Arizona State University, a co- investigator on the Imager for Mars Pathfinder (IMP) team.

"We have a view of Mars that we have never seen before," added Dr. Matthew Golombek, project scientist at JPL. "We really have a grab bag of rocks here, varying in color, texture, fabric, sizes and shapes. They are completely different from the Viking landing sites and from each other too."

Scientists expect to begin reporting results of the first day of science activities at a 10 a.m. PDT press briefing at JPL. Meanwhile, all instruments and spacecraft systems continue to perform exceptionally well. The operations team will be increasing Pathfinder's data rate to more than 8,000 bits per second tomorrow in order to maximize the return of science measurements.

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