Boeing

NASA's Mars Exploration Rover (MER)-B, also named "Opportunity," is set for launch on June 28 from Space Launch Complex 17B, Cape Canaveral Air Force Station, Fla., aboard a Boeing [NYSE: BA] Delta II rocket.

The launch will occur at an instantaneous window of 11:56:16 p.m. EDT. A second launch opportunity exists approximately 41 minutes later on June 29 at 12:37:59 a.m. EDT, if necessary.

Opportunity, the second of two rovers being launched this month for NASA, will fly aboard a Delta II 7925H-9.5, Boeing's Delta II Heavy configuration launch vehicle, and will be deployed approximately 80 minutes after liftoff.

The primary goal of the MER missions is to study past water activity on Mars by examining the planet's geology. Data from the two rovers will enable scientists to determine if life existed on Mars and to prepare for human exploration of Mars.