A、Monday B、Sunday C、Tuesday D、Wednesday A

Bad weather forced mission managers to postpone launching NASA’s Messenger spacecraft on a Boeing Delta 2 rocket early on Monday.
   Managers stopped the launch because of clouds near the pad at a critical point in the countdown. The minuscule 1 E-second launch window left no time to try again.
   NASA hopes to try again early on Tuesday.
   Messenger is set to begin a 4. 9 billion mile journey to orbit the planet Mercury and collect data on the planet’s geology and atmospheric composition. It will be the first spacecraft to visit the planet since Mariner 10 whizzed by three times in 1974 and 1975. It will also be the first spacecraft ever to orbit the planet.
   Launch controllers have until Aug. 14 to launch the spacecraft. After that, planetary alignment issues will postpone the launch for about a year. Upcoming launch opportunities will also have extraordinarily short launch windows.