Mar. 17, 2011 NASA's versatile Mars Reconnaissance Orbiter,
which began orbiting Mars five years ago March 10, has radically
expanded our knowledge of the Red Planet and is now working
overtime. The mission has provided copious information about
ancient environments, ice-age-scale climate cycles and present-
day changes on Mars. The orbiter observes Mars' surface,
subsurface and atmosphere in unprecedented detail. The
spacecraft's large solar panels and dish antenna have enabled it
to transmit more data to Earth -- 131 terabits and counting,
including more than 70,000 images -- than all other
interplanetary missions combined. Yet many things had to go well
for the mission to achieve these milestones. After a seven-month
journey from Earth, the spacecraft fired its six main engines
for nearly 27 minutes as it approached Mars on March 10, 2006.
Mars could not capture it into orbit without this critically
timed maneuver to slow the spacecraft. The orbiter's intended
path took it behind Mars, out of communication,