NASA engineers had almost finished robotic arm tests of Mars rover Curiosity in preparation for it to touch and examine its first Martian rock, the US space agency announced Wednesday.

Tests with the 2.1-meter arm had allowed the mission team to gain confidence in the arm's precise maneuvering in Martian temperature and gravity conditions, the agency said.

During these activities, Curiosity remained at a site it reached by its most recent drive on September 5, and two instruments -- a camera and a spectrometer -- had passed preparatory tests at the rover's current location, it added.

The team will resume driving the rover this week and use its cameras to seek the first rock to touch with instruments on the arm.

"We're about to drive some more and try to find the right rock to begin doing contact science with the arm," said Jennifer Trosper, Curiosity mission manager at NASA's Jet Propulsion Laboratory.

Curiosity is five weeks into a 2-year prime mission on Mars. It will use 10 science instruments to assess whether the selected field site inside Gale Crater has ever offered environmental conditions favorable for microbial life.