Messenger approaches Mercury
The insertion into orbit starts at about 9 p.m. ET on March 17. From that point on, Messenger will fly a 12-hour orbit at a minimum altitude of about 124 miles. The spacecraft's science instruments will be turned on and checked out starting on March 24.
March 17, 2011 4:00 AM PDT
Photo by: NASA artist's rendering
| Caption by: Jonathan Skillings
Conversation powered by Livefyre