Delta Launch From The Cape

Watch a Delta II launch the GPS Block 2R military navigation satellite on Thursday, 16 November. Live feed from the Kennedy Space Center

Here’s the latest from Spaceflight Now:

2230 GMT (5:30 p.m. EST)

Preparations continue for tomorrow’s launch of the Boeing Delta 2 rocket carrying a replacement satellite for the Global Positioning System, but bad weather at Cape Canaveral is threatening to delay the liftoff. Launch will be possible between 2:17 and 2:30 p.m. EST (1917-1930 GMT).

A cold front will be sliding through Central Florida on Thursday, and Air Force forecasters expect the Cape to feel the brunt of the stormy weather between 3 and 11 a.m. A severe weather watch has been issued.

Gradual clearing is predicted later in the day, but rain, lingering thunderstorms and thick clouds still pose a high concern for the mid-afternoon launch. There is a 70 percent chance that conditions will be unacceptable at liftoff time.

Mission managers will meet before dawn to assess the latest weather outlook and determine if it’s safe to retract the mobile service tower from around the rocket at pad 17A. Winds cannot exceed 39 knots for the move, plus officials must be confident of no hazardous weather looming on the horizon that could harm the rocket while it stands exposed on the pad for the final hours of the countdown.

Tower rollback is targeted to occur around 6 a.m. The retraction could be postponed a couple of hours without impacting the launch time.

Air Force officials say their strategy, assuming weather is safe enough to retract the tower, will be pressing forward with the launch opportunity. An early decision to scrub is unlikely unless the launch time forecast gives absolutely no hope of allowable conditions, they said. As of right now, there is that 30 percent chance that the storms will clear in time.

The outlook for Friday is beautiful, forecasters say.