During the spacecraft's seven-month journey to Mars, engineers still had lots of work to do back on Earth to make sure the spacecraft was "healthy" and ready to make new scientific discoveries when it arrived at Mars.
| Beginning of cruise phase: | Mission engineers conducted an initial spacecraft checkout. Once they determined the orbiter was in normal operating mode, they began preparations for the first adjustment to the spacecraft's path, known as a trajectory correction maneuver. |
| Early part of cruise phase: | During a payload checkout period lasting about one week, engineers checked out the
instruments on the orbiter. The science team sent software updates to the instruments. Engineers also calibrated the performance of several spacecraft subsystems, including the thrusters, the high-gain antenna, and the gyros. They conducted an in-flight UHF test between the orbiter's Electra payload and the Stanford UHF antenna. |
| Middle of cruise phase: | For about two weeks, the mission team measured the performance and alignment of the spacecraft instruments through payload calibrations. To perform these calibrations, they directed the orbiter to point at specific known references to make sure the instruments were working correctly. For cameras, reference points included known star fields. For SHARAD, reference points included known sources of radio waves such as a pulsar star or the planet Jupiter. |
