The mobile service tower on Space Launch Complex 17B at the Cape Canaveral Air Force Station in Florida was rolled away from the United Launch Alliance Delta II heavy rocket starting at about 11:20 p.m. EDT Wednesday in preparation for Thursday's scheduled launch of NASA's GRAIL lunar mapping mission.
GRAIL remains on track for two instantaneous (one-second) launch windows at 8:37:06 a.m. (12:37:36 GMT) or if needed, 9:16:12 a.m. (13:16:12 GMT).
The Delta II's first stage has been loaded with almost 10,000 gallons of refined kerosene, known as RP-1. Liquid oxygen is now being loaded.
Forecasts call for a 40 percent chance of acceptable weather at liftoff time. The concern is the possibility of thick clouds and rain near Launch Complex 17B.
During the 6:30 a.m. weather briefing to the launch team, clouds had not thickened so far, so there is some optimism that conditions will allow a launch.
If not, the same conditions will persist on Friday, with an improving weather picture for the weekend.
Credit: United Launch Alliance/Thom Baur
[i][b]Above[/b]: Delta II-GRAIL rocket as seen just after the Mobile Service Tower was moved back from the vehicle.[/i]