Messenger spacecraft poised for insertion into Mercury orbit

Messenger spacecraft poised for insertion into Mercury orbit

Mission managers at the Johns Hopkins University Applied Physics Lab in Maryland will put the brakes on the NASA spacecraft so it can begin orbiting the closest planet to the sun. If successful, Messenger will beam at least a year's worth of images and other data back to Earth.
Reporting from Baltimore
Fifteen years of planning and 6 1/2 years of maneuvering in space will all come down to one moment Thursday as mission managers try to slip NASA's Messenger spacecraft into orbit around Mercury.

The braking operation, playing out 96 million miles from Earth, will have to slow the desk-size planetary probe by 1,929 mph and ease it into a polar orbit around the planet closest to the sun.

Failure will leave Messenger's managers at the Johns Hopkins University Applied Physics Lab with a fuel tank less than 10% full and limited options for recovery. And that would put the primary goal of the $446-million mission at risk.