HiRISE has done it again.

The UA Lunar and Planetary Lab team that operates the high-resolution camera aboard the Mars Reconnaissance Orbiter captured a clear, stunning image of the Mars rover Curiosity descending by parachute toward the surface of Mars on Sunday night.

The single image had been planned for months, and after Curiosity, formally known as the Mars Science Laboratory, landed at 10:31 p.m. Sunday, the Tucson-based team waited for it.

About 1:30 a.m. Monday it received it. It clearly showed the Curiosity capsule suspended from its giant parachute, plunging toward the Martian surface.

It was the second image of a Martian landing caught by the HiRISE team, led by Alfred McEwen. HiRISE had also captured the descent of the Phoenix Mars Lander in May 2008.

The photo was planned months in advance, said McEwen of the University of Arizona's Lunar and Planetary Lab.

The orbiter and the HiRISE camera had to be carefully positioned at the right place at the right time. The time delay in transmissions left no room for last-minute changes.

"We rely on the engineers to calculate everything perfectly for us," McEwen. "It's just math. You just have to double- and triple- and quadruple-check everything."

The team remained at work Monday night, improving the original image and angling to capture an image of Curiosity on the Martian surface.

It will continue to devote time to Curiosity over the coming years, taking additional photos of Gale Crater where the rover landed.

Repeat photography has shown it to be an area where there are "active dunes," said McEwen. "We've seen some changes over time, and they need to cross that dune field."

Peter Smith, who led the University of Arizona team that operated the Phoenix Mars Lander that successfully reached Mars in May 2008, said McEwen told him he had a 50-50 chance of getting the image.

It was an amazing accomplishment, said Smith, but landing Curiosity was an even bigger one.

Landing a spacecraft on Mars is no slam-dunk, said Smith, who is a veteran of four Mars missions, including one that disappeared without a trace.

The successful landing Sunday is "worthy of a gold medal" for the American team, he said Monday at a luncheon of the Astronomical Society of the Pacific, which is holding a science-education conference in Tucson.

Smith, also with the UA's Lunar and Planetary Lab, had been in charge of a camera on the Mars Polar Lander, which disappeared in 1999.

"We got so cocky as a team that we didn't bother to put in communication during landing," he said. "So we sent in the spacecraft and never heard another word from it."

Landing on Mars is complicated by its thin atmosphere, said Smith. It creates enough drag to require shielding the craft from the intense heat, but not enough resistance to slow the craft with a parachute alone.

Sunday's landing employed a heat shield, a parachute and a device dubbed the "sky crane" which used thrusters to hover above the surface while Curiosity was lowered on cables.

Smith jokingly referred to it as the "rover on a rope."

"When you first hear about it," said Smith, "you say, 'These guys are insane.' "

Smith, who followed the successful landing with a group of mission veterans at the Phoenix Mars Lander offices Sunday night, said it wasn't the same feeling of excitement he had with the mission he led. "The exciting thing is that when it lands safely, you have nothing more to do."

On StarNet: See more photos from Curiosity rover's landing on Mars at azstarnet.com/gallery


The HiRISE camera, developed at the University of Arizona, has been circling Mars aboard the Mars Reconnaissance Orbiter since March 2006.

The camera - its full name is the High Resolution Imaging Science Experiment - has captured a series of historic and detailed pictures of Mars' surface and in 2008 captured an image of the Phoenix Mars Lander as it descended to the red planet.

HiRISE is run from the Lunar and Planetary Laboratory on the UA campus. HiRISE images were used to find a safe landing site for the Phoenix Mars Lander, efficient travel paths for the Mars rover Opportunity, and to evaluate and select a landing site for the Mars Science Laboratory, which landed in Gale Crater on Sunday.

Contact reporter Tom Beal at tbeal@azstarnet.com or 573-4158.