Mars Rovers: Picture Perfect Robots -- An Interview with Jim Bell

Taking its own self-portrait, Spirit Mars rover is shown in full exploration mode within Gusev Crater. Image CREDIT: NASA/JPL/Cornell

There's majesty on Mars. Through the lenses of two wheeled robots--Spirit and Opportunity--the red planet's austere but stunning landscape has been captured in thousands of images relayed back to Earth.

Before humans on Mars pose themselves for those take home photographs, our eyes have already been firmly planted on that time-weathered world.

Both NASA rovers remain hale and hardy as they near three years of rolling about within their respective exploration zones after setting down to business on Mars in January 2004.

Each rover made the trip with carry on luggage: science instruments and cameras. And now thanks to a new book, Postcards from Mars (Dutton, 2006), an extraordinary gallery of hand-picked images shows Mars in first-time format.

Huge volume

"I'm a tactile book person. I like the printed page and seeing images," explained Jim Bell, author of Postcards from Mars, a landscape photographer since he was a child. He is an associate professor in the Cornell University Astronomy department and leader of the team who designed and operate the color Panoramic Camera (Pancam) systems on the twin Mars rovers.

While the images taken by Spirit and Opportunity can be found posted across the Internet, it's often difficult to find them all in a single spot, Bell told SPACE.com. "So I thought it would be a good idea to gather my impression of the greatest hits to date in one place," he added.

So far, the rovers have collectively churned out over 160,000 images, Bell noted.

Put that in focus with the Viking Mars landers of the 1970s that relayed 1,400 images. Then there's the 1997 mission of Mars Pathfinder/Sojourner that transmitted about 16,000 images.

"We've had spectacular orbiters relaying the data to Earth for us. So we've been able to downlink so much more," Bell pointed out. For the book, he had a huge volume of Spirit and Opportunity imagery to cull through that were taken into late spring of 2006.

Foldouts from another world

The Pancam on each rover provides a truly human viewpoint, Bell observed. In terms of resolution and natural color, the rovers are providing the best look to date of what it's like to actually stand there on Mars.

Mars scenery as caught by each Pancam--from about a meter and a half above the landscape--is at the height of a typical 10 year old kid.

Bell stressed that he doesn't have a favorite between the two robots. "Each of them is so different. The discoveries each has made are complementary, but different. I wanted to keep that balance in there," he said, so the book's photo spreads are pretty evenly split between Spirit and Opportunity.

Admittedly, there were tough decisions about the set of foldouts for the book--select views that reflect the sweeping topography of Mars.

"I tried to make a representative sampling of the different kinds of terrain that we have driven through," Bell said.

Making tracks

How does one go about picking "greatest hits" from the treasure trove of rover photographs? The book showcases over 150 of Bell's favorites.

"Most of the time we haven't had the luxury of thinking like photographers and composing images. It's been a rare luxury...something we haven't been able to do that often," Bell responded.

Having parts of the rover in the foreground, be it outstretched robot arm, solar array, or the deck of the Mars machinery, gives a sense of depth of field, Bell said. "The other thing that seems to resonate well with the public is seeing the rover tracks."

Bell explained that the wheel tracks imprinted in martian surface are particularly appealing when they converge off toward the horizon.

"It just gives you a sense of adventure, exploration...you think of a covered wagon...a dune buggy. You just think of traveling," Bell suggested. "You can imagine yourself being out there and seeing this scene. It's a natural, bizarre alien scene but here are these tracks. They are a familiar thing. Here's a car driving across the landscape."

Next real leap

Despite the dual rovers being given an A-plus on their photo assignments, the limelight will be shared given future hardware now being readied for Mars.

Next summer, NASA's Phoenix Mars lander departs for the red planet's icy north pole. Its cameras are akin to the rover Pancams, using the same detectors and comparable optics.

The next real leap in surface camera equipment is to be toted by NASA's Mars Science Laboratory (MSL), a huge rover that blasts off in 2009.

MSL's mast cameras--Mastcam for short--would capture the martian terrain in color photos, three-dimensional images, and high-definition video. New features on the Mastcam would make it more versatile than previous rover cameras.

Bell is on the Mastcam team led by Michael Malin of Malin Space Science Systems of San Diego, California.

"It's a wonderful camera system that can go in color to a resolution about three times better than the rover Pancams," Bell explained. "It's going to be a beautiful, beautiful imaging system."

Blood, sweat and tears

Meanwhile, Spirit and Opportunity soldier onward.

Putting together Postcards from Mars, Bell said was a very emotional experience. "Seeing it all in one place...all the different scenes. It shows the amount of team work and collaboration. It represents the blood, sweat and tears of hundreds and hundreds of people."

Today, Spirit is perched for more action, ready to tackle new observations near the Columbia Hills.

Planetary partner, Opportunity, is taking astounding imagery from the edge of the huge Victoria Crater. Chances are good that this robot will wheel itself down into that large feature, Bell said.

"It's incredible how much our attitude has changed from early on...when it was just rush, rush, rush, thinking that we're going to die at any moment. Now we're thinking long-term because we've been able to," Bell said. More good news is that the cameras on both rovers remain in good, sharp-shooting shape, he added.

So Postcards from Mars, Volume 2, might seem right?

"No kidding, with the way we're going," Bell concluded.

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