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Mars Pathfinder is right on course for a landing in Ares Vallis, an ancient outflow channel in the northern hemisphere of Mars, at 10:07 a.m. Pacific Daylight Time today.
The navigation team reported that the final trajectory correction maneuver, which could have been performed either 12 hours or six hours prior to Pathfinder's entry into the upper atmosphere, was not necessary. An early morning orbital update indicated that Pathfinder was heading straight for the center of its 60-mile-by-120-mile landing ellipse and was expected to enter the upper atmosphere at a 13.9-degree angle, just three-quarters of a degree off its original entry angle of 14.2 degrees. Pieter Kallemeyn, navigation team chief, estimated that the spacecraft would touch down at 19.0 degrees north latitude, 326.3 degrees east longitude.
"To give you an idea of the accuracy that we have achieved here, this is the equivalent of playing a round of golf in which the hole is in Houston, Texas, and the tee-off is in Pasadena, California," Kallemeyn said. "We're basically hitting a hole in one here."
Spacecraft events prior to landing will include release of the cruise stage at about 9:32 a.m. PDT; entry into the upper atmosphere at about 10:02 a.m. PDT; and landing 4.5 minutes later.
The spacecraft is currently about 198,000 kilometers (123,000 miles) from Mars, traveling at a velocity of about 24,500 kilometers per hour (15,277 miles per hour) with respect to Mars.
The flight team expects to receive the first low-gain signal from the spacecraft at about 2:07 p.m. PDT. Contained in that transmission will be information about the spacecraft's entry, descent and landing, atmospheric science data and details on the health of the lander and rover.
Mars Pathfinder successfully landed on the surface of Mars at 10:07:25 a.m. Pacific time, marking NASA's historic return to the red planet after more than 20 years.
The Pathfinder flight team received nearly instantaneous confirmation that the spacecraft had landed from an independent antenna mounted on one of the spacecraft's petals. Detection of the very weak signal, which came as a surprise, also indicated that the craft had landed on its base petal, thus eliminating the spacecraft's next task: to stand itself upright before deploying its petals.
Approximately 90 minutes after landing, engineering data indicated that Pathfinder had fully deployed its petals and was awaiting sunrise on Mars to power up. The flight team reported that the lander came to rest about 12 miles southwest of its targeted landing spot and was resting on the surface at a very slight tilt of about 2.5 degrees.
Pathfinder's first low-gain antenna transmission was received right on time at 2:07 p.m. PDT. The transmission contained preliminary information about the health of the spacecraft and rover, the spacecraft's orientation on the surface, data about its entry, descent and landing, and a first look at the density and temperatures of the Martian atmosphere.
Preliminary data from the atmospheric science instrument indicated that temperatures are somewhat warmer than they were in the Viking days of the mid-1970s. Dr. Timothy Schofield, principal investigator of the atmospheric science team, said early data suggested it was about minus 220 degrees Celsius (minus 64 degrees Fahrenheit) at the landing site.
The Mars Pathfinder imaging team tonight unveiled the first photograph of Ares Vallis, an ancient water channel that at one time in Mars' early history carried more than 1,000 times the amount of flowing water carried by the Amazon River today. The color panorama, which drew enthusiastic applause at a 6:30 p.m. press briefing, was taken by the lander's Imager for Mars Pathfinder camera -- called the "IMP" -- before the camera was deployed on its mast. The photograph revealed a rocky desert scape with numerous large boulders and mountains on the horizon.
The images were transmitted during Pathfinder's first high- gain antenna transmission, which began at 4:28 p.m. PDT today. Totaling about 120, the postage stamp-sized black-and-white frames also included close-up photographs of the lander petals with the rover sitting in its stowed position in the foreground. Closer examination showed that one of the airbags did not fully retract and had become draped slightly over the edge of the rover's petal.
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The Pathfinder flight and rover teams decided to test a new command sequence that would pull the obstructed petal up about 45 degrees, further retract the airbag, then lay the petal down again. The team tested this command sequence before uplinking it to the spacecraft starting at about 7:08 p.m. PDT. Return images from that transmission will be used by the rover team to determine if the "petal move" sequence cleared the petal enough to allow for safe deployment of the rover ramps. Part of the image data were not received during the next downlink session due to a problem with the Deep Space Network tracking station. The remaining images were scheduled to be retransmitted during the last transmission of the day, which was to begin at 10 p.m. PDT.
If ramp deployment is postponed, the flight team will perform this activity Saturday morning. The rover would then be ready to roll off its ramp and onto the surface of Mars by about 5 p.m. PDT July 5.
For more information, please visit our website at http://mpfwww.jpl.nasa.gov.