Thursdays west coast launch

The launch of the Aquarius/SAC-D spacecraft aboard a United Launch Alliance Delta II rocket remains on schedule for Thursday, June 9 at 7:20 a.m. PDT (10:20 a.m. EDT) from NASA's Space Launch Complex 2 at Vandenberg Air Force Base. Launch and mission officials gathered at a news conference Tuesday afternoon to offer previews of the countdown and the mission to come.

"In just two short days, the Aquarius/SAC-D satellite will be launched into orbit, and those of us on mission team could not be more excited," said Aquarius Program Executive Eric Iansen.

NASA's Aquarius instrument is part of the SAC-D spacecraft built by CONAE, Argentina's space agency. The mission is expected to to gather global measurements of ocean surface salinity, leading to a better understanding of ocean circulation, climate and Earth's water cycle. Once in orbit, the spacecraft will go through a checkout period before it begins its three-year mission, said Amit Sen, Aquarius Project Manager.

NASA Launch Director Omar Baez provided an overview of the countdown. The mobile service tower surrounding the rocket will be retracted from around the launch vehicle at approximately 10 p.m. PDT Wednesday (1 a.m. EDT Thursday). The terminal countdown begins at 5:15 a.m. PDT (8:15 a.m. EDT) launch day with the loading of cryogenic liquid oxygen into the Delta first stage. Baez will clear the vehicle for launch at T-3 minutes.

Vernon Thorpe, NASA Project Manager for United Launch Allaince, pointed out Thursday's liftoff will mark the 149th launch of a Delta II rocket. "This mission represents the culmination of years of hard work by teams at NASA, CONAE and ULA," Thorp said. "We anticipate that our Delta II vehicle will perform well."

Launch Weather Officer Capt. Shawn Hannah predicts favorable weather on Thursday morning, with a zero percent chance of conditions violating launch weather criteria. In the event of a 24-hour delay, the forecast is the same for Friday.

Live on NASA TV and the ULA website.