Cornell on Mars: "We hit the sweet spot"

Shortly after the successful landing, an exuberant Steve Squyres answers reporters' questions. Copyright © Cornell University Click on the image for a high-resolution version (1800 x 1200 pixels, 831K)

PASADENA, Calif. -- Welcome to Mars, Cornell.

The Mars rover vehicle, Spirit, made a pinpoint landing on the planet shortly after 11:35 p.m. EST on Saturday, Jan. 3, and only three hours later began returning its first pictures.

The bouncedown landing and the 12-minute transmission of about 60 images was a huge success for NASA and a tribute to the Cornell-led science team that over the next three months or so will send the golf cart-size rover on a voyage of exploration as far as a kilometer (.64 mile) from the landing site in the Gusev Crater.

"What a night," said an exultant Steven Squyres, the Cornell astronomy professor who heads the Mars mission's science team, after an evening of mounting tension that broke only when mission controllers at the Jet Propulsion Laboratory (JPL) in Pasadena acquired the first signals that the rover was safely on the surface. The landing sequence took the spacecraft from 19,000 kilometers an hour (12,000 miles per hour) to a complete stop in just six minutes.

Amazingly, the rover lander appears to have settled less than 10 kilometers (about 6 miles) from the center of the landing "ellipse," an imaginary runway in Gusev Crater targeted by mission planners. "We hit the sweet spot," said Squyres at a press briefing Sunday morning at JPL.

After looking at the first low-resolution pictures from the vehicle he said, "Spirit has shown us her new home and it's a glorious place." The site, he said, looks very much like a dry lake bed, although it's too early to say if the landscape shown in the first pictures shows sedimentary rocks or lava deposits. The landing site "looks tailor-made for our vehicle and we're looking forward to some good driving in the weeks and months ahead."

NASA chose Spirit's landing site based on evidence from Mars orbiters that Gusev Crater might have held a lake long ago. The crater is a basin the size of Connecticut created by an asteroid or comet impact. Spirit will spend the coming months exploring for clues in rocks and soils for evidence that Mars once had conditions suitable to sustain life.

The compilation of the mosaic images of the landing area, transmitted via the orbiting Odyssey spacecraft, was the responsibility of a team led by Cornell associate professor of astronomy James Bell. "I'm elated," said Bell, surrounded by his team of Cornell students and alums. "Our primary job now is to see that the cameras are healthy, and calibrated, that they survived the bounces." He described the landing as "awesome."

Saturday afternoon, prior to the landing, a TV crew interviews Prof. Jim Bell, lead researcher for the rover's panoramic camera. Copyright © Cornell University Click on the image for a high-resolution version (1800 x 1200 pixels, 659K)

Spirit travel 487 million kilometers (302.6 million miles) to Mars after its launch from Cape Canaveral Air Force Station, Fla., on June 10, 2003. Its twin rover, Opportunity, was launched on July 7, 2003, and is on course for a landing in Meridiani Planum on the opposite side of the planet on Jan. 25 at 5 minutes after midnight EST.

What seemed so incredible to many was the apparent trouble-free landing that left the Spirit lander standing upright on its base petal, allowing the deployment of the solar panels and the full charging of the rover's batteries. By Sunday morning, Pacific time, engineers with JPL, the mission manager, were able to say that the rover's mechanical systems seem to have survived the bouncedown and that the lander seems in a good position to lower its front ramp for the vehicle's descent onto the crater floor. That won't happen for about another 9 days. But over the coming day or two the rover, now folded in a crouched down position, will be lifted up from its belly and its front wheels released.

"We now know with great certainty we are where we wanted to be in Gusev Crater, a marvelous place," said Squyres. His team has located the area by comparing a picture taken by the lander's descent system camera just 1 kilometer above the ground with pictures of the area taken from the Odyssey.

About three hours after the landing, the first pictures from Mars appear on a NASA wall screen. Copyright © Cornell University Click on the image for a high-resolution version (1800 x 1200 pixels, 827K)

Squyres described the terrain around the lander as littered with little rocks. "It is way too early to talk about anything to do with the composition or texture of the rocks," he said. But the area is "remarkably devoid of big boulders, which is glorious news" because big boulders make for difficult rover driving.

An intriguing feature that is exciting Squyres and his science team is a "strange-looking" depression-like feature clearly visible in the images from the ground that "might well be a wonderful feature that would tempt us in a particular direction." Squyres said he is "willing to bet" that the depression has been filled in during recent geological time with fine-grain soil. The images indicate, he said, that the crater floor has been swept clean of dust by the Martian wind with dust left only in hollows.

Discovery Channel Canada producers Ben Schaub and Ivan Semeniuk view the lastest images from Mars through 3D glasses in the press room at JPL Robert Barker/Cornell University PhotographyCopyright © Cornell University Click on the image for a high-resolution version (1800 x 1200 pixels, 2MB)

At a Monday morning press conference Squyres said that after a night spent studying the images--which the news media were able to view with 3D glasses--the science team had calculated that the depression is about 30 feet in diameter and about 40 to 50 feet from the lander. Most intriguingly, he noted, two black patches are evident in the depression, which he speculated might be bounce marks from the airbag-enclosed lander, made after it was released from its descent parachute and bounced several times across the Gusev Crater before coming to rest. Because of the midnight hours spent studying the feature, the team has named it Sleepy Hollow.

The newly named feature might be the rover's first target when it descends from the lander in a week or so. Possibly, Squyres said, the rover could reach Sleepy Hollow in a single day, although he cautioned that the initial forays are likely to be carried out with great caution. "We haven't earned our Martian driver's license yet," he quipped.

Squyres and members of the science team are now living on Mars time. For them, this is Sol 3, or the third day on the planet.

Next from the rover will be the transmission of data that will result in the first high-resolution, color panoramic image of the Martian surface that will be 14 times sharper than the first low-resolution images received.

The mosaic of 12 color frames is stored in the rover's onboard computer for transmission to JPL, hopefully on Monday night. The images were captured by the rover's mast-mounted panoramic camera, called the Pancam, developed by Bell's team. The Pancam mast can swing the camera 360 degrees across the horizon and 90 degrees up or down.

"I can't wait to see it," said Squyres of what he called the "Pancam postcard." He told the international press corps that is giving front-page newspaper and live broadcast coverage to the mission, "I bet we are more eager to see it than you are."

- 30 -