LOS ANGELES — Operators at NASA’s Jet Propulsion Laboratory are starting the second and final phase of instrument checkout on the robotic arm of the Mars rover Curiosity, which is stationary after traveling 268 ft. away from the Bradbury Landing touchdown site.

The rover, which continues to be in good health, is about a quarter of the way to a target area called Glenelg, where it is scheduled to conduct science investigations in an area where three types of terrain intersect. However, assuming the checkout of instruments on Curiosity’s robotic arm goes as planned, the rover team says it may stop on the way to analyze fine-grained rocks or loose soil.

Characterization Activity Phase (CAP) 2 is focused on checking out the tools and their movement on the arm. These are all critical to Curiosity’s main mission of looking for signs of past or current life on the planet and include the drill for acquiring powdered samples from inside rocks as well as an Alpha Particle X-ray Spectrometer (APXS). The arm also houses a sample processing subsystem called Chimra (Collection and Handling for In-Situ Martian Rock Analysis), as well as a dust-removal tool and the Mars Hand Lens Imager (Mahli), which can focus on grain sizes as small as talcum powder.

Researchers are also analyzing the first sample of the Martian atmosphere that was ingested into the SAM (Sample Analysis at Mars). An initial checkout revealed that more air from Earth’s atmosphere remained in the instrument after launch than expected. A second sample, taken on Sept. 2-3 with the rover pointing upwind to avoid contamination, is being analyzed.

A major focus is the search for methane, the presence of which has been suggested by other observations. What produces methane on Mars, if confirmed, remains a mystery.

JPL is currently in Sol (Martian day) 2 of the planned 7-8-sol CAP 2 checkout phase, says Matt Robinson, lead engineer for Curiosity robotic arm testing and operations. On Sol 33 (Sept. 8), the team plans to use Mahli to take photos of calibration targets as part of the characterization of the arm and its motion in Mars low gravity, which is 38% that of Earth. Mahli also will peer underneath Curiosity to take shots of the rover’s belly and check its condition.

After this, Curiosity’s arm is scheduled to move to a local “playground” area “to test out contact switches and localize the arm and find the surface. The APXS instrument will then be placed on a target for similar characterization tests. “Then the plan is to head to Glenelg and on the way to stop when we either encounter a fine-grained rock or loose scoopable material we can put in the Chimra,” says Crisp, who adds the drill may be used for the first time at the Glenelg site.