NASA says a maneuver Tuesday adjusted the flight path of its Mars Science Laboratory spacecraft for delivering the rover Curiosity to a landing target on Mars.

The car-size, 1-ton rover is set to arrive at Mars Aug. 6 to begin a two-year mission to investigate whether Mars ever offered an environment favorable for microbial life.

The latest trajectory correction maneuver -- the third and smallest since the spacecraft's Nov. 26, 2011, launch -- used four thruster firings totaling 40 seconds in duration, engineers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., reported.

The maneuver served both to correct errors in the flight path and to carry out a decision to shift the landing target about 4 miles closer to the martian mountain next to Curiosity's intended landing site.

Shifting the landing target closer to the mountain 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, scientists said.

"This puts us closer to our entry target, so if any further maneuvers are needed, I expect them to be small," JPL's Tomas Martin-Mur, the mission's navigation team chief, said.