The U.S. National Aeronautics and Space Administration is aiming to find out whether life forms can survive on Mars. First, they need to pull off a successful landing of a 1-ton rover named Curiosity.
The vehicle, loaded with the most-sophisticated instruments ever used to explore another world, is scheduled to touch down Aug. 6 at about 1:30 a.m. New York time. If successful, the $2.5 billion mission is expected by scientists to return a trove of data on the geology of a planet that's been shrouded in myth.
The mission may also help reignite an interest in space that's waned since the Apollo 11 moon landing in 1969, said Nilton Renno, a mission scientist, bolstering support for U.S. funding for more projects and inspiring a new generation of students to explore the stars.
"You can see in the eyes of the students how excited they get by working on something like this mission," Renno said in a telephone interview. "It's mind-blowing that we can send an instrument to another planet and operate it from earth, understanding something so far away."
By analyzing air, rock and soil samples collected by Curiosity, scientists may be able to tell whether the Mars environment is conducive to life, said Renno, who is also a professor in Atmospheric, Oceanic, and Space Sciences at the University of Michigan in Ann Arbor.
Success isn't a sure bet. Of 19 previous U.S. missions to Mars, six have failed, according to NASA, the agency running the mission. To get there, the rover will undergo a complicated descent and landing sequence never before attempted.
NASA has dubbed that fall from space "7 Minutes of Terror" in a video describing the onrushing event.
The spacecraft will enter the atmosphere and decelerate quickly, deploying a parachute. It will then separate into parts, one of which will be a hover craft with rockets.
That part, referred to by NASA as a "sky crane," is supposed to lower Curiosity to the ground without damaging it. The hover craft will then fly away. It's a new system that replaces the airbags used in previous mission to lessen the impact since Curiosity is too heavy to use them, according to the agency's online reports.
The craft will be landing in a region humanity didn't previously have the technology to reach, said Bobby Braun, a professor of space technology at the Georgia Institute of Technology, who was NASA's chief technologist in 2010-2011.
The mission will begin at the foot of a 3.4 mile (5.5 kilometer) high mountain in Gale Crater. Previous expeditions have landed on plains, he said.
"Curiosity is the kind of spacecraft you can't do on a tight budget," Braun said by telephone. "There are missions that can be done at lower expense, but you can't build a rover that's the size of a car and nuclear-powered and carrying a laser and other equipment and safely land it on Mars."
There's a 14-minute communication lag between the vehicle and the control center 154 million miles away on Earth, where scientists will constantly monitor transmissions from the craft. By the time NASA gets notice that the device has entered the atmosphere, Curiosity will have already landed. The journey to the surface, from the atmosphere, is seven minutes.
Braun, who is on the review board for the mission, says he's optimistic about the engineering behind the Curiosity rover. He hopes this mission will make scientific discoveries so compelling that they will make the case for future expeditions to Mars, helping hold off a planned 20 percent funding cut, from $1.5 billion to $1.2 billion, to planetary science in President Barack Obama's 2013 Presidential Budget Request.
"If budget cuts come, that will slow the pace of our planetary exploration journey," Braun said, adding that with a failure on its hands NASA would face a situation in which they "won't be able to get to the next chapter as quickly, and that's a real sham."
Still, he's confident. "The mission appears risky, but I don't view this as a risky mission," he said.
Though other big space projects, such as the James Webb Space Telescope, remain on the schedule, it's getting harder to get funding for projects the size of the Curiosity mission, said Michael Lubell, the director of public affairs for the American Physical Society, said in a telephone interview.
"Nobody wants to step up to the plate and take a whack at something big," he said. "We've become single hitters rather than homerun hitters."
The Mars Science Laboratory, the formal name of the mission deploying the Curiosity rover, was launched from Cape Canaveral in Florida, on Nov. 26, 2011. In February, because of its cost, the U.S. backed out of the Mars Sample Return mission, a project coordinated with the European Space Agency meant to bring back Martian soil and rocks to be examined in local labs.
After Curiosity, the only planned U.S. mission to Mars is an atmospheric orbiter meant to launch next year.
Knowledge of Mars has bolted ahead in the last 20 years, Braun said. That's due entirely to the orbiters, expeditions and probes sent to examine the planet.
"When I started in the Mars program, we thought of it as dry, dusty and lifeless," Braun said. "In the last 20 years, we've shown that Mars was much warmer and wetter, and that means life may have emerged billions of years ago, just like on Earth.
The rover's instruments were created to detect the chemistry of life, said Arlin Crotts, a professor of astronomy at Columbia University. The planet has water and an unusual amount of methane in its atmosphere, which may indicate that some sort of organisms may have existed there.
By checking for organic compounds on the planet, the rover can tell scientists if there were conditions for life.
"If we find life on Mars, it's not just 'oh, great, Mars has bugs,"' Crotts said in a telephone interview. "It might tell us if life is common in the universe. If it is, what does that mean? We know that there are earthlike planets orbiting stars, but we don't know how frequently life gets started."
Just knowing that the environment might be habitable could inspire careers, Crotts said.
"I was born just after Sputnik," Crotts said. "I was just so inspired by the space program, and so now I'm an astrophysicist."