Guy Norris and Frank Morring, Jr. Pasadena, Calif.

The large team of engineers and scientists living on Mars time at the Jet Propulsion Laboratory here are rapidly learning to operate the nuclear-powered Curiosity rover, which continues to perform almost faultlessly on the floor of Gale Crater.

Checkout of the complex suite of instruments designed to gauge the habitability of Mars, past and perhaps present, continues to go well. The Mars Science Laboratory (MSL) engineering team has completed a changeout from the software designed to transport the rover from Earth to the surface of Mars over to the package Curiosity will need to operate semiautonomously for the next two Earth years.

Scientists have started mapping the terrain it must cross to reach the canyon in the side of the crater's central mountain, dubbed Mount Sharp in tribute to planetary scientist Robert P. Sharp, that is the scientific target of the mission. And the team that must write as many as 1,000 rover commands a day during full-up operations has started working without a net, with the preloaded command sequences for the most part all run now (see p. 30).

The MSL Curiosity team will have its first chance to conduct geochemical science, and even go for a short drive, sometime late this week, assuming the commissioning process continues to stay on schedule, says NASA.

So far, John Grotzinger, the mission chief scientist, says the chances are extremely good that this activation process will go well, judging by the success of the mission to date.

“We're pinching ourselves,” says Grotzinger, who oversees the elite group of planetary-science specialists who will try to wring as much knowledge as possible out of the rover's instruments. “All the instruments have passed their 'liveness' checks. Everything is fine, as far as we can tell.”

However, Grotzinger cautions that the true health of some of the more sophisticated instruments, such as the Sample Analysis at Mars (SAM), will not be confirmed for “weeks, if not months” because of the many complex subsystems in play. SAM is the largest of the 10 instruments on Curiosity. It combines in a single microwave-oven-sized box three analytical tools that the space agency says would take up a “good portion” of a standard laboratory on Earth. Using samples collected with Curiosity's 6.2-ft. robotic arm, SAM will study chemistry relevant to life, and check for carbon-based compounds with mass and laser spectrometers and a gas chromatograph.