Workers begin placing a protective cover around the MESSENGER spacecraft is scheduled for Aug. 2.

Workers from the Johns Hopkins University Applied Physics Laboratory in Laurel, Md., begin placing a protective cover around the MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) spacecraft at Astrotech Space Operations in Titusville, Fla. Bagging the Mercury-bound MESSENGER precedes its placement in a transportation canister for the journey to Launch Pad 17-B at Cape Canaveral Air Force Station, Fla. Liftoff of MESSENGER aboard a Boeing Delta II Heavy rocket is scheduled for Aug. 2. The spacecraft is expected to reach orbit around the planet in March 2011. MESSENGER was built for NASA by APL.