On Tuesday, NASA adjusted the flight path of Mars Science Laboratory spacecraft on for delivering the rover Curiosity to a landing target at Gale Crater.The car-size, one-ton rover is bound for arrival the evening of Aug. 5, 2012, PDT (early Aug. 6, EDT and Universal Time). The landing will mark the beginning of a two-year prime mission to investigate whether one of the most intriguing places on Mars ever offered an environment favorable for microbial life.
"This puts us closer to our entry target, so if any further maneuvers are needed, I expect them to be small," said JPL's Tomas Martin-Mur, the mission's navigation team chief. Opportunities for up to three additional trajectory correction maneuvers are scheduled during the final eight days of the flight.
The maneuver served both to correct errors in the flight path that remained after earlier correction maneuvers and to carry out a decision this month to shift the landing target about 4 miles (7 kilometers) closer to the mountain. It altered the spacecraft's velocity by about one-tenth of a mile per hour (50 millimeters per second). The flight's first and second trajectory correction maneuvers produced velocity changes about 150 times larger on Jan. 11 and about 20 times larger on March 26.
Shifting the landing target closer to the mountain, informally named Mount Sharp, may shave months off the time needed for driving from the touchdown location to selected destinations at exposures of water-related minerals on the slope of the mountain.
The flight to Mars has entered its "approach phase" leading to landing day. Mission Manager Arthur Amador of JPL said, "In the next 40 days, the flight team will be laser-focused on the preparations for the challenging events of landing day -- continuously tracking the spacecraft's trajectory and monitoring the health and performance of its onboard systems, while using NASA's Deep Space Network to stay in continuous communications. We're in the home stretch now. The spacecraft continues to perform very well. And the flight team is up for the challenge."
Descent from the top of Mars' atmosphere to the surface will employ bold techniques enabling use of a smaller target area and heavier landed payload than were possible for any previous Mars mission. These innovations, if successful, will place a well-equipped mobile laboratory into a locale especially well suited for its mission of discovery. The same innovations advance NASA toward capabilities needed for human missions to Mars.
As of June 27, the Mars Science Laboratory spacecraft carrying the rover Curiosity will have traveled about 307 million miles (494 million kilometers) of its 352-million-mile (567-million-kilometer) flight to Mars.
Recent mapping has revealed the presence of Medusae Fossae (MFF) materials close to the Gale crater landing site. The primary goal for Curiosity is to look for chemical evidence of ancient life preserved within exposures near the base of a five-kilometers high mound of layered materials at the center of Gale crater.
Because of its history, 96-mile wide Gale Crater crater with its strangely sculpted mountain --three times higher than the Grand Canyon is deep--is the ideal place for Curiosity to conduct its mission of exploration into the Red Planet's past. Researchers plan to use Curiosity to study layers in the mountain that hold evidence about wet environments of early Mars.
"This may be one of the thickest exposed sections of layered sedimentary rocks in the solar system," said Joy Crisp, MSL Deputy Project Scientist from NASA's Jet Propulsion Laboratory. "The rock record preserved in those layers holds stories that are billions of years old -- stories about whether, when, and for how long Mars might have been habitable."
An instrument on Curiosity can check for any water that might be bound into shallow underground minerals along the rover's path. Today the Red Planet is a radiation-drenched, bitterly cold, bleak world. Enormous dust storms explode across the barren landscape and darken Martian skies for months at a time. But data from the Mars Reconnaissance Orbiter suggest that Mars once hosted vast lakes and flowing rivers.
"Gale Crater and its mountain will tell this intriguing story," says Matthew Golombek, Mars Exploration Program Landing Site Scientist from JPL. "The layers there chronicle Mars' environmental history."
The Daily Galaxy via NASA