This artist concept features NASA's Mars Science Laboratory Curiosity rover, a mobile robot for investigating Mars' past or present ability to sustain microbial life.

July 24: Today, Curiosity's two lithium ion rechargeable batteries are being recharged to 100 percent of capacity in preparation for entry, descent and landing. The batteries, which have been maintained at a 70-percent state of charge during the cruise to Mars, are being recharged using power from Mars Science Laboratory's cruise-stage solar array. The batteries enable Curiosity's power subsystem to meet peak power demands of rover activities when the demand temporarily exceeds the onboard multi-mission radioisotope thermoelectric generator (MMRTG) steady output level. With a capacity of about 42 amp-hours each, the batteries are expected to go through multiple charge-discharge cycles per Martian day.