NASA follows Mars successes with plans for $2B super Rover

Following up on what's been called some of NASA 's most successful technology, the space agency is pushing ahead with plans to launch an SUV-sized Rover to Mars next year.

The Mars Science Laboratory is on track to launch next fall, despite mounting costs and the work it will take to ready the machine. With an estimated budget of $2 billion, the super Rover will carry three different kinds of cameras, chemistry instruments, environmental sensors and radiation monitors. All of these instruments, according to NASA, are designed to help scientists figure out whether life ever existed on Mars and prepare to send humans to the Red Planet.

In a press conference late last week, Doug McCuistion, director of the Mars Exploration Program at NASA headquarters, said that to stay on schedule, the agency will need more financing, though he did not specify how much will be needed. Scientists are forging ahead with the hope that funding will come for the project.

NASA has been heavily focused on exploring Mars with two Rovers, the Lander and an orbiter already studying the planet.

And with the success that NASA has had with the two Rovers working on Mars, there's a lot of excitement brewing to send up a new one.

The two Rovers, Spirit and Opportunity, which wave been motoring around Mars for nearly five years, are some of the best pieces of technology that the Jet Propulsion Laboratory has ever built, said Bruce Banerdt, project scientist for the Mars Exploration Rovers.

"It is amazing. Every day I just have to tip my hat to the engineers who designed them," Banerdt said. "They were supposed to design them to last for a 90-day mission ... Of course, I can guarantee that nobody expected them to last this long. We've had to actually rewrite all the software on the Rovers because the calendar system keeps track of how many days it's been on Mars and they only [were set for] 1,000 days. We had to rewrite the software so everything wouldn't shut down. It was like Y2K. Now the joke is we only have four digits so when we get to 10,000 days we'll have another problem on our hands."

The Rovers, which are working on the equator but on different sides of the planet, have been on Mars just three months shy of five years. The machines have been sending and receiving information from Earth every day with a team of about two dozen programmers and engineers uploading code to guide the Rovers' movements and aim its cameras. All of that information travels about 200 million miles one way, taking anywhere from five to 21 minutes to travel from one planet to the other.

The Spirit Rover has traveled 4.5 miles across the surface of Mars, while its counter part, Opportunity, has ventured more than seven miles.

"Considering it may not be that far for a person to walk, but try it holding your breath for four and a half years," said John Callas, project manager of the Mars Exploration Rover Project. "Remember these Rovers are hundreds of millions of kilometers away in a hostile environment, exploring. They operate autonomously on Mars."

Callas explained that in order for the Rovers to accomplish their tasks, they have to be aware of their environment and then make judgments about it. To help them do that, they have many cameras arranged in stereo pairs to give the Rovers depth perception and a digital model of their world. They can calculate the size of rocks, the slope of the land and the distance to objects. They also are capable of deciding if it's safe to go over a particular rock or if a slope in the ground is gentle enough to traverse.

"They do the same things we do with our eyes and brains when we're out walking," Callas told Computerworld .

Each Rover runs on a single, radiation-hardened processor that's based on the PowerPC architecture. They're powered by an array of solar panels that feed energy into onboard rechargeable batteries. When the sun comes up, the machines wake up and go to work and then go back to sleep, saving their energy, at the end of the day.

The problem, according to Callas, is dust, which accumulates on the solar arrays and could hinder them from capturing the sunlight they need. So far, though, wind has kept the dust from building up and becoming too much of a problem.

"Our greatest challenge was about a year ago, when they encountered a global dust storm that threatened to kill both [of the Rovers]," said Callas, noting that the storm lasted about two months. "Without their solar power, they were at risk of freezing to death. We were able to manage the power very carefully and keep the Rovers safe till the storm passed."

Banerdt noted that the two Rovers have greatly extended scientists' understanding of Mars, and he's eager to get a third working machine, especially one with five times the mass and more sophisticated equipment than the others, up on Mars.

"The Rovers were designed to go down to the surface and look at the rocks which contained evidence about the history of Mars," he said. "The minerals you find in a rock tell you a story about the environment in which the rocks were formed??? The Mars Rovers looked at the effects of water billions of years ago. We know there was quite a bit of water out there at that time. It maybe wasn't Earth-like, but it was more Earth-like than it is today.

"We can't say if life occurred there, but what we've been able to establish is that the conditions for life to survive were in place," he added.

The initial cost for the two 90-day Rover missions rang in at about $650 million, according to Banerdt, who added that NASA is spending about $20 million a year to operate them. He estimated that the entire price tag for Spirit and Opportunity will range around $800 million.