Mission control engineers in California will spend the next four days remotely installing new computer software in Curiosity that essentially reorients the brains of the six-wheeled vehicle for maneuvering around the surface of the Red Planet.

The nuclear-powered rover, about the size of a small sports car, can only store so much pre-programmed information in its computer module at once, having less on-board memory capacity than a typical cell phone.

Its previous flight-control software was tailored for the complex tasks of atmospheric entry, descent and landing that brought the mobile science lab to a historic touchdown on the floor of a vast, ancient impact basin called Gale Crater earlier this week.

A new version of the software, uploaded to Curiosity while it was still en route to Mars, is instead specially designed to let NASA engineers safely drive the rover, operate its robot arm, use its power drill, collect samples, sweep away dust and perform other functions as it goes about its science mission.

"Curiosity was born to drive. This software includes the capability for Curiosity to really go out and stretch her wheels," Benjamin Cichy, the rover's senior software and systems engineer, told reporters on Friday at the Jet Propulsion Laboratory near Los Angeles.

The new software package will be installed on Curiosity's main computer and its backup.

All other activities will be suspended for the most part during the upgrade, which was set to begin Friday night, California time, at the start of Curiosity's fifth full day on Mars. Instrument checks, picture-taking and science operations are scheduled to resume on Day 9 of the mission.

Curiosity arrived on Mars Sunday night on a quest for evidence that the planet most similar to Earth may once have harbored the basic ingredients necessary for the evolution of microbial life, or may even now be capable of supporting life.

The $2.5 billion project, formally named the Mars Science Laboratory, is NASA's first astrobiology mission since the Viking probes of the 1970s and is touted as the first full-fledged mobile biochemistry lab ever sent to a distant world.

The rover comes equipped with an array of sophisticated instruments capable of analyzing samples of soil, rocks and atmosphere on the spot and beaming results back to Earth.

The principal target of its exploration is a 3-mile- (5-kilometer) high tower of layered rock, named Mount Sharp, which is believed to have formed from sediment that once filled Gale Crater. The mound, which stands a short distance from Curiosity's landing site near the center of the crater, is seen by Mars scientists as a potential gold mine of geologic study.

An initial review of data collected from Curiosity's arrival on Mars revealed that it blasted through the planet's thin atmosphere at 24 times the speed of sound, pulling the equivalent of 11 times the force of Earth's gravity.

"If you were a human riding on board, it'd be a little bit of a rough ride, but fortunately Curiosity is made of some tough stuff," said Gavin Mendeck, who oversaw the rover's entry. It landed just 1.5 miles (2.4 km) from the center of its projected landing zone.

The rover's chief engineer, Rob Manning, came closest to predicting the exact spot where Curiosity ended up touching down. He also oversaw some of the team's readiness testing.