Ten years of planning the most sophisticated robotic mission to another planet will boil down to a tense seven minutes tonight, when the Jet Propulsion Laboratory-managed rover Curiosity is scheduled to land on the surface of Mars for a two-year search for evidence of life.
Following its launch from Cape Canaveral, Florida on Nov. 26, 2011, NASA's new rover is scheduled to touch down Sunday at 10:31 p.m.
You can watch the landing live on the Griffith Observatory's channel on LiveStream, based out of Southern California.
"The Curiosity landing is the hardest NASA mission ever attempted in the history of robotic planetary exploration," said John Grunsfeld, associate administrator for NASA's Science Mission Directorate in Washington, D.C. "While the challenge is great, the team's skill and determination give me high confidence in a successful landing."
Curiosity is a one-ton, car-sized rover billed by NASA and JPL as the most scientifically advanced robotic vehicle ever dispatched. The rover carries 10 science instruments, including a mast that extends to seven feet above ground for cameras and a laser-firing apparatus to study objects from a distance. The rover also includes analytical instruments to determine the composition of rock and soil samples collected with the rover arm's drill and scoop.
The rover also has instruments to study the planet's environment, including the weather and natural radiation.
But before all of those instruments can be put to work, Curiosity needs to land intact.
That landing will come after what JPL engineers in Pasadena are calling "seven minutes of terror," during which scientists will be monitoring the novel method of delivering the rover to the planet's surface.
Previous Mars rovers such as Spirit and Opportunity plunged through Mars' atmosphere in protective air-bag-like structures, allowing them to literally bounce onto the planet's surface.
Curiosity is far too large for that type of landing, so mission planners had to come up with something different. Upon entering the Martian atmosphere, the spacecraft will deploy a supersonic parachute.
To get the rover on the surface, NASA engineers came up with "sky-crane" system to lower it on tethers.
During a period of about seven minutes, the spacecraft will have to decelerate from a speed of about 13,200 mph to about 1.7 mph as it descends. During the final seconds of the flight, Curiosity will be lowered on three nylon cords — with the assistance of retro rockets to control its descent speed — onto the surface of the planet, wheels first.
"Those seven minutes are the most challenging part of this entire mission," said Pete Theisinger, the $2.5 billion Curiosity mission's project manager at JPL. "For the landing to succeed, hundreds of events will need to go right, many with split-second timing and all controlled autonomously by the spacecraft. We've done all we can think of to succeed. We expect to get Curiosity safely onto the ground, but there is no guarantee. The risks are real."
Because of delayed communications across 35 million miles of space, it will take mission controllers about 14 minutes to find out if their "seven minutes of terror" pays off in an successful landing.
The rover, which blasted into space from Cape Canaveral on Nov. 26, is expected to land at the foot of a mountain inside the Gale Crater, which is 96 miles across. The mountain, known as Mount Sharp, within the crater is taller than Mount Rainer, which is about 14,400 feet. JPL officials said the site is believed to have once had liquid water on the surface.
After the rover touches down, mission controllers will put it through a series of checks before it begins its primary task -- determining whether the area inside the crater has ever sustained an environment favorable for microbial life.
NASA officials said previous missions have determined that Mars once had wet environments, but Curiosity is designed to determine if those environments ever had the potential for supporting life. Mission managers noted that Curiosity's primary work area is on a slope of Mount Sharp, but it will likely take the rover several months to drive from its landing spot to the research area.
"It will be well worth the wait, and we are apt to find some targets of interest on the way," according to John Grotzinger, a Mars Science Laboratory project scientist at Caltech. "When we get to the lower layers of Mount Sharp, we'll read them like chapters in a book about changing environmental conditions when Mars was wetter than it is today.