LOS ANGELES (AP) — NASA's latest rover to Mars fired its thrusters Wednesday to adjust its course to the red planet for a landing in August.
Deep space antennas tracked the choreographed maneuver, which was expected to last three hours.
The firing of its eight thruster engines is the most important task Curiosity will perform during its 352-million-mile trip, 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 had racked up 80 million miles and was traveling at 10,200 mph relative to the Earth.
The team uploaded commands for the trajectory correction maneuver a day earlier. Though the rover was executing the move without human interference, engineers were on standby in the off chance of a need to abort.
"We should be very, very close to our desired aim point at the top of the Martian atmosphere" after the maneuver, Amador said.
If Curiosity did not tweak its route, it would miss Mars altogether because it was initially not aimed at the planet. Engineers did this by design to prevent the upper stage of the rocket that launched the spacecraft from hitting Mars. Once Curiosity separated from the upper stage and was on its way, the team has several chances to fine-tune its trajectory before touchdown.
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.
Armed with a suite of instruments including a laser to zap into bedrock and a jackhammer, Curiosity is more sophisticated than previous Mars surface spacecraft. Despite its capabilities, it won't be able to detect life. Instead, it will hunt for the chemical building blocks of life during its two-year mission.
Since Curiosity is too heavy to use a cocoon of airbags or rely solely on its parachute to safely reach the planet's surface, NASA will attempt a new type of landing using a so-called sky crane system.
The parachute will detach and a rocket-powered platform will fire its engines, then lower the rover to the ground on a tether similar to the way hovering heavy-lift helicopters lower huge loads at the end of a cable.
Even before arrival, Curiosity has not been idle. Several weeks after launch, Curiosity turned on its radiation detector to monitor high-energy particles streaming from the sun and exploding stars. Once at Mars, it will measure radiation levels on the surface.
Curiosity's voyage contrasts sharply with another space probe targeted at the Mars moon Phobos. Launched weeks earlier than Curiosity, Russia's Phobos-Ground probe got stranded in Earth's orbit and pieces were expected to plunge back through the atmosphere this weekend.