James Dean

FLORIDA TODAY

Update: 2:30 p.m., Wednesday, Dec. 15:NASA and Orbital ATK have announced a launch attempt will be made Thursday, Dec. 15. Tune in to floridatoday.com Thursday morning beginning at 6:30 a.m. for live video and analysis of the Pegasus XL launch.

Update, 6 a.m. Wednesday, Dec. 14:

NASA and Orbital ATK have postponed this morning's planned attempt to launch a Pegasus rocket and the CYGNSS mission due to a software issue involving the eight microsatellites.

The issue was discovered during routine testing on Tuesday. The fix will be uploaded today, and the launch could be ready to go again Thursday morning, when there's an 80 percent chance of favorable weather.

"Next launch attempt will be determined pending testing," NASA said in a tweet.

A first launch attempt on Monday (Dec. 12) was scrubbed by a problem with the hydraulic system that releases the Pegasus from the L-1011 aircraft. Orbital ATK flew in a replacement circuit breaker from California.

Schedule of upcoming Florida rocket launches

The air-launched Pegasus will be flying for the first time since 2013, and the first time from Cape Canaveral Air Force Station since 2003.

Led by scientists from the University of Michigan, the CYGNSS mission aims to launch eight microsatellites that each weigh about 60 pounds and, with solar wings deployed, are described as about the size of a swan.

For at least two years, the satellites will fly in a band round the globe 315 miles over the tropics. By picking up signals from Global Positioning System satellites that reflect off the ocean surface, the constellation will calculate wind speeds at the center of storms.

Current satellites and aircraft can't take those measurements as often, and their signals may not be able to penetrate heavy rains.

Contact Dean at 321-242-3668 or jdean@floridatoday.com. And follow on Twitter at @flatoday_jdean and on Facebook at facebook.com/jamesdeanspace.