August 5, 2012
Mars Curiosity Closing In On Seven Minutes Of Terror
April Flowers for redOrbit.com - Your Universe Online
Curiosity Rover is approaching the red planet at about 8,000 mph, on the way to its date with destiny and the history books. However, that is not the upper limit of speed for Curiosity. Mar's gravity is taking hold and pulling the rover down hard. By the time the spacecraft hits the top of Mars' atmosphere, about seven minutes before touchdown, Martian gravity will accelerate it to approximately 13,200 mph.
"After flying more than eight months and 350 million miles since launch, the Mars Science Laboratory spacecraft is now right on target to fly through the eye of the needle that is our target at the top of the Mars atmosphere," said Mission Manager Arthur Amador of NASA's Jet Propulsion Laboratory, Pasadena, Calif.
The Atlas V rocket powered spacecraft is on course and on target for delivering Curiosity to the Gale Crater and Mt. Sharp at 10:31 p.m. tonight, PDT (1:31 a.m. Monday, EDT). That is when NASA expects to get a signal confirming a safe landing, give or take a minute due to atmospheric conditions. As of 2:25 p.m. PDT today, Curiosity was approximately 261,000 miles from Mars.
NASA will receive that safe landing signal via relay from the Mars Odyssey orbiter. Curiosity will not have direct communication with Earth because the Earth will set below the Martian horizon about two minutes before Curiosity sets down. Landing is the biggest hurdle NASA expects Curiosity to face, so those few minutes of delay will be tense and critical.
Mars itself even seems to be welcoming Curiosity. A dust storm in southern Mars that is being monitored by NASA's Reconnaissance Orbiter appears to be dissipating. "Mars is cooperating by providing good weather for landing," said JPL's Ashwin Vasavada, deputy project scientist for Curiosity.
The plan is for Curiosity to investigate whether the study area in Gale Crater has ever offered the right environmental conditions favorable for microbial life, including the chemical ingredients for life. According to two University of Tennessee researchers, Linda Kah and Jeffrey Moersch, critical evidence may include frozen water, organic compounds, or other chemical ingredients.
“In particular, we will be examining sedimentary rocks that form Mount Sharp, which is a more than five-kilometer-high mountain within Gale Crater, the area the rover is exploring,” said Kah. “These rocks might serve as a time capsule of Mars´s transition from a warm, wet planet to a cold, dry one.”
Kah and Moersch are searching in different ways. Kah is part of a camera team searching for features within rocks that might provide clues to the rules of fluids in the planet's past. Moersch is searching for hydrogen in the form of water, ice or hydrated minerals. They aren't' the only scientists working on these problems, though. Twice a day, data will be downlinked and disseminated to five teams of scientists, all looking for signs of ancient life.
“I expect that we will find evidence for the building blocks of life, although that is a far cry from actually finding evidence for life,” said Kah. “Personally, I am more excited by the opportunity to ask a whole set of higher-order questions about what the Martian surface was like and how it might have changed through time.”
The first pictures from Curiosity will be reduced-resolution fisheye black-and-white images during the first hours after touchdown. Higher resolution and color images will be transmitted later in the first week. Plans are for Curiosity to deploy a directional antenna on day one and raise the camera mast on day two.
The process of searching is slow. Curiosity will only be moving about 200 meters a day, on a good day. The mission is slated to continue through 2014, two full years on Earth, but only one year on Mars.