NASA rover aims for August Mars landing

A NASA spacecraft hurtling toward Mars prepared to fire its thrusters yesterday to put itself on course for an August landing.

Engineers closely tracked the one-ton rover nicknamed Curiosity, which has been cruising along since rocketing from Earth last November.

The firing of its eight thruster engines is the most important task Curiosity will perform during its 352-million-mile flight to the red planet, but it's not unprecedented. Previous robotic explorers have had to adjust their paths several times en route to landing.

"Just because this is a well-traveled road to Mars, given the number of trips we've made, I'm very careful to not let that experience cause us to be complacent," said Arthur Amador of the NASA Jet Propulsion Laboratory, which manages the $2.5 billion mission.

At the time of the course correction, Curiosity will have racked up 80 million miles and will be traveling at 10,200 mph relative to the Earth.

The day before, the team uploaded commands calling for the spacecraft to fire its eight thrusters for nearly three hours yesterday afternoon, redirecting it closer to its target.

"We should be very, very close to our desired aim point at the top of the Martian atmosphere," Amador said.

Curiosity, whose formal name is the Mars Science Laboratory, is aiming for a 96-mile-wide crater near the Martian equator that boasts a towering mountain in the center. The six-wheel, nuclear-powered rover planned to drive to the lower flanks and examine the layered deposits to determine whether the area once had conditions capable of supporting microbial life.