An unfavorable weather forecast as a result of Tropical Storm Isaac approaching Florida kept at Cape Canaveral Air Force Station.

An unfavorable weather forecast as a result of Tropical Storm Isaac approaching Florida kept NASA's twin Radiation Belt Storm Probes, or RBSP, on Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida. Managers decided to roll the Atlas V rocket off the launch pad and back to the Vertical Integration Facility to ensure the launch vehicle and RBSP spacecraft are secured and protected from inclement weather.

RBSP will explore changes in Earth's space environment caused by the sun -- known as "space weather" -- that can disable satellites, create power-grid failures and disrupt GPS service. The mission also will provide data on the fundamental radiation and particle acceleration processes throughout the universe. The launch is rescheduled for 4:05 a.m. EDT on Aug. 30, pending approval from the range. For more information on RBSP, visit http://www.nasa.gov/rbsp. Photo credit: NASA/Ben Smegelsky