Five NASA probes will have to wait at least one more day to begin hunting for the source of dynamic auroras after high winds above their launch site prevented a planned Friday liftoff.
The launch scrub occurred just minutes before NASA's five THEMIS spacecraft were expected to ride a United Launch Alliance Delta 2 booster spaceward at 6:05 p.m. EST (2305 GMT) from Pad 17B at Cape Canaveral Air Force Station in Florida.
Launch is now reset for Saturday during an 18-minute window that opens at 6:01 p.m. EST (2301 GMT).
Unacceptable winds were the only concern for today's planned space shot, which at times had a 90 percent chance of favorable flight conditions at launch time.
Launch controllers sent up a series of weather balloons during today's countdown to monitor changing wind conditions.
"The final weather balloon showed red for upper level winds," NASA launch commentator Jessica Rye said.
The delay marked the second this week for THEMIS, a $200 million mission to find the origin of substorms in the Earth's magnetic field that are responsible for the most colorful light displays in the aurora borealis, or Northern Lights.
Thunderstorms and severe weather prevented the fueling of THEMIS' Delta 2 booster for a planned Feb. 15 launch attempt.
Short for the bulky title Time History of Events and Macroscale Interactions During Substorms, THEMIS consists of five identical probes designed to circle the Earth in ever-higher orbits ranging between one-sixth and one-half the distance between the Earth and Moon. The probes are designed to spend about two years monitoring the Earth's magnetosphere for the tell-tale release of high-energy particles that signal a substorm.
Researchers hope the THEMIS mission will aid understanding and prediction of space weather. The mission a cooperative effort between NASA's Goddard Space Flight Center in Greenbelt, Maryland and the Space Sciences Laboratory at the University of California, Berkeley.