NASA has postponed the liftoff of two space radiation satellites to no earlier than Aug. 30 due to expected stormy fallout from Tropical Storm Isaac, space agency officials said Saturday.
The space agency announced the launch delay just hours after thunderstorms thwarted an attempted early-morning launch from Cape Canaveral Air Force Station in Florida during a 20-minute window that opened at 4:07 a.m. ET.
With Tropical Storm Isaac expected to reach hurricane strength this weekend, mission managers for the twin Radiation Belt Storm Probes, or RBSP, opted to roll the Atlas 5 rocket carrying the $686 million satellites back inside its protective hangar for safekeeping.
"This will ensure the launch vehicle and twin RBSP spacecraft are secured and protected from inclement weather," NASA officials said in a statement.
The radiation-monitoring mission is now slated to launch on Aug. 30, at 4:05 a.m. ET, they added.
Tropical Storm Isaac is expected to reach hurricane strength Saturday or Sunday as it moves northwest on a course toward Florida's panhandle, according to a National Hurricane Center forecast. [Amazing Photos from Inside Tropical Storm Isaac]
Space news from NBCNews.com
Teen's space mission fueled by social media
Science editor Alan Boyle's blog: "Astronaut Abby" is at the controls of a social-media machine that is launching the 15-year-old from Minnesota to Kazakhstan this month for the liftoff of the International Space Station's next crew.
- Buzz Aldrin's vision for journey to Mars
- Giant black hole may be cooking up meals
- Watch a 'ring of fire' solar eclipse online
- Teen's space mission fueled by social media
Saturday's postponed launch was the second delay in two days for the Radiation Belt Storm Probes mission. An issue with a rocket tracking beacon, needed to monitor the mission's Atlas 5 rocket during liftoff, thwarted a Friday launch attempt late in the countdown.
Even earlier this week, NASA pushed back the first launch try from Thursday to Friday, to allow time to clear up a separate technical concern with the Atlas 5.
NASA's Radiation Belt Storm Probes mission is a two-year project to study the radiation belts around Earth. These belts, called the Van Allen Belts, are regions of harsh radiation that can be affected by strong solar storms that can pose a threat to satellites and astronauts in orbit, as well as communications and power infrastructure on Earth.
The new storm probes are expected to study the regions to help improve space weather forecasting and help design better spacecraft to withstand the harsh space radiation environment, NASA officials said.
- In Images: Hurricane Season 2012
- How NASA's Twin Radiation Belt Storm Probes Work (Infographic)
- NASA's Radiation Belt Storm Probe Mission in Pictures
© 2013 Space.com. All rights reserved. More from Space.com.