With a successful launch behind them and a long cruise ahead, MESSENGER mission operators are checking out the systems on the Mercury-bound spacecraft.

"MESSENGER is in great shape and well on its way," says Mission Operations Manager Mark Holdridge, of the Johns Hopkins University Applied Physics Laboratory, which built and operates MESSENGER.

Artist's impression shows MESSENGER departing Earth. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Since liftoff on August 3 the operations team has checked out MESSENGER's communications system, getting strong signals from its high-, medium- and low-gain antennas through NASA's Deep Space Network. It will check the guidance and control system this week before moving on to some of the spacecraft's science instruments. The team also continues to monitor power and temperature levels on the spacecraft, now more than 1.5 million miles from Earth.

MESSENGER is tentatively scheduled to carry out its first trajectory correction maneuver on Aug. 24, firing its small thrusters to adjust the course that will bring it back to Earth for a gravity-assist flyby next summer.

"We're going to take as long as we need to make sure every system works the way it's supposed to," Holdridge says. "Now that we've launched, we have time on our side."

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a scientific investigation of the planet Mercury, and the first NASA mission designed to orbit the planet closest to the Sun. Dr. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland, built and will operate the MESSENGER spacecraft and manages the Discovery-class mission for NASA.