The launch of THEMIS aboard a Delta II rocket scheduled for Thursday, Feb. 15, has been postponed 24 hours. Loading of hypergolic propellants aboard the second stage of the vehicle was unable to be completed today. Thunderstorms and severe weather moved into the Cape Canaveral vicinity ahead of an advancing cold front that prevented fueling from continuing.

Launch Day will begin with the retraction of the launch pad's mobile service tower at 9 a.m. EST. Next, crews will begin filling the first stage with RP-1 kerosene fuel at 3:30 p.m. The pumping of liquid oxygen aboard the first stage will follow at 4:15 p.m. Once the propellants are aboard the rocket, the countdown will continue to a liftoff between 6:05 and 6:23 p.m. EST.

On Feb. 3, THEMIS was transported from Astrotech payload processing facility near NASA Kennedy Space Center to Pad 17-B. The five satellites and their rocket were then subjected to a combined systems check to ensure everything is ready for the flight into space on launch day. Following the test, technicians installed the Delta II rocket's protective payload nose fairing around THEMIS.

The Mission

THEMIS is a mission to investigate what causes auroras in the Earth's atmosphere to dramatically change from slowly shimmering waves of light to wildly shifting streaks of color. Discovering what causes auroras to change will provide scientists with important details on how the planet's magnetosphere works and the important Sun-Earth connection.