NASA Probe Successfully Orbiting Mercury—A First
After more than six years and several million miles, NASA's MESSENGER spacecraft is now in orbit around the tiny planet Mercury.
Launched in 2004, the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission marks the first time a craft has gone near Mercury since 1975, when NASA's Mariner 10 probe conducted flybys. (Get MESSENGER facts and figures.)
For the past six and a half years MESSENGER has been maneuvering itself into an orbital path via so-called gravity assists, using the tugs from flybys of Earth, Venus, and Mercury itself to speed up and alter course.
At 8:45 p.m. ET, MESSENGER performed a "burn"—essentially "riding its brakes" by firing its main thruster—to slow the spacecraft enough to be captured by Mercury's gravity.
The mission control team at the Johns Hopkins Applied Physics Laboratory in Maryland was monitoring MESSENGER's progress
