• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Year Later, Physicist Recalls Success of Mars Landing

Posted on: Tuesday, 4 January 2005, 12:00 CST

By KEITH ROGERS

REVIEW-JOURNAL

Aside from astronauts, cosmonauts and a handful of other space pioneers, Jesse Wright is about as close as a person has come to being a man from Mars.

Like all Earthlings, he still was more than 100 million miles away from where the rover, Spirit, survived a mile-long tumble in an air-cushioned ball across a Mars crater a year ago today.

A self-proclaimed "telemetry software wonk" raised and educated in Las Vegas, Wright was one of about 40 scientists in the war room at NASA's Jet Propulsion Laboratory in California.

Like other members of the entry-and-landing team, the 49-year- old physicist was sweating out the possibility things would go wrong. If so, he'd be one of the first that his bosses at the space agency would call on for answers.

"It was very nerve-wracking," he said last week from Pasadena, Calif. "If the Spirit landing failed, we'd have approximately two weeks to analyze data, fix the problem and test the problem."

Then, Wright said, he'd have to draw up new software based on such factors as temperature, pressure, acceleration of Spirit to send to the second rover, Opportunity, that eventually landed on Mars on Jan. 24.

As it turns out, Spirit made a perfect landing and 98 percent of the expected data was relayed to Earth through the global surveyor orbiting Mars. Communication through the Mars Global Surveyor, originally designed for a Russian balloon instrument package that never made it to Mars, worked better than he had imagined.

"It was like a wave of warm weather going through me. I was happy when it landed but elated when we got data from it," said Wright, a Clark High School graduate who earned a physics degree from UNLV in 1979.

Opportunity experienced similar success, transmitting 99 percent of expected data after a landing that turned out to be "a hole in one. It went right into this crater on Mars," Wright said. "That was amazing. We could never have planned on that happening ... that we rolled into a crater with bedrock material and it was so big that we couldn't get out of it."

He described the task of the rover spacecraft entering the thin Martian atmosphere speeding at 22,000 mph.

As with other problems he learned to solve in college, "you break it down to a step. How do you enter the atmosphere? There you use a heat shield, because coming through the atmosphere will heat it up.

"To land softly, if you want it slow enough, you put out a parachute. What you do to slow down the spacecraft even further you have rockets" to counter the fall, he said.

Then, air bags are deployed and the craft drops eight stories to the surface of Mars.

"There's a factor of luck involved. If you know what's going on, you know a lot of things could have gone worse," Wright said.

The Spirit landing was a learning experience, he said, which taught the team how to control the spacecraft through adjustments.

Wright was involved in solving a two-week lull in receiving data from Spirit because too many computer files were causing the system to shutdown and then reload. The onboard computer essentially was stuck in a loop.

"So we sent a command to say, 'Don't use that file system. Use a backup file system,' " said Wright, technical manager for the ground data system used in the 1997 Mars Pathfinder mission.

Most of Spirit's files contained science data and photographs from cameras that are stored on board and then relayed to three large antennas on Earth.

The "big science" upshot of all that data was that scientists found there was liquid water on Mars, it was there for a long time and there was a lot of it.

Wright said the rovers proved to be "quite rugged little pieces of equipment."

Now he's working on what changes need to be made in the software for the rovers to handle their 1,000th day on Mars.

Data show dust accumulates on solar panels used to power them, resulting in less power generation. But after dust builds up, strong winds or a more unusual process somehow clears them off, he said.

"This was beyond my dream that I would be working on this," Wright said.

He believes people someday will live on Mars, but "not in my lifetime."

"We might get somebody to Mars in my lifetime. It's so basic in the human equation to explore and do new things. I can't see why they wouldn't do that on Mars."

Source: Las Vegas Review - Journal

More News in this Category