Launch Timeline up to the abort (reverse order):

All times are in EST unless otherwise stated.

9:44 a.m. - Assistant NASA Launch Manager Omar Baez has announced they will have to stand down for at least 48 hours to change out the fin batteries -- and they still have to figure out what went wrong with the flight control pins.

9:41 a.m. - The Stargazer L-1011 will land on Vandenberg's runway 12.

9:38 a.m. - The launch team is "go" for the Stargazer, still carrying the Pegasus rocket, to return to the base.

9:30 a.m. - The Pegasus rocket has been safed at this time. The pins associated with the steering controls could not be retracted. The Stargazer aircraft is going to return to Vandenberg. SIGI, the Pegasus navigation system, has been reconfigured for captive carry.

9:28 a.m. - Abort. The drop has been aborted. We've waved off.

9:24 a.m. - SIGI is configured for flight. Launch window has been verified as "go."

9:23 a.m. - L-4 and counting. The L-1011 has entered the box. Orbital Launch Conductor Adam Lewis is conducting the final launch readiness poll and the launch team is go to proceed with the final checklist.

9:21 a.m. - Avionics internal power supply is on.

9:20 a.m. - Pegasus is go for avionics internal power.

The NASA statement said that a new launch date will be established pending resolution of the issue, the availability of the Western Range, and acceptable weather conditions at the Vandenberg Air Force Base, Calif. launch site. The delay will be at least 48 hours.

Looking to buy a used airplane or for an aviation job? Be sure to check out our new airplanes for sale and engineer jobs sections.

Please support AeroSpaceNews.com with a paid subscription.

It is also very important for you to please fill out our readership survey if you have not already done so. Please take a moment right now. Click here to fill out the survey.

Thank you!