Vandenberg Air Force Base is scheduled to assist in the launch of a Pegasus XL rocket — carrying a NASA solar observatory satellite — during a five-minute window starting at 7:27 p.m. Thursday.

The 30th Space Wing will provide range, safety and weather support for the operation, which includes the 6:27 p.m. launch of an L-1011 carrier aircraft. An Orbital Sciences Corporation Pegasus XL rocket will deploy from the aircraft about an hour later.

The launch, which was originally scheduled for Wednesday, was postponed a day because of an issue with the base electrical power architecture.

The two-year IRIS mission, short for Interface Region Imaging Spectrograph, will point a telescope at the interface region of the sun to improve understanding of how energy moves from the sun’s surface to the million degree outer atmosphere called the corona, according to NASA.

After launching in an aircraft from Vandenberg, the Pegasus — NASA’s only winged launcher — and its IRIS payload will be carried to about 39,000 feet before the plan drops the Pegasus to begin the launch.

The spectacle could be seen along the Central Coast if the sky is free of low clouds, since the rocket will release about 100 miles northwest of Vandenberg and then travel south down the coast, said George Diller, a NASA spokesman.

“If we have relatively clear sky, you would see it coming down the coast,” Diller told Noozhawk. “We know that it can be seen if the weather’s good.”

Officials are still waiting for final weather conditions, but Diller noted that a similar launch from the Lompoc area in clear skies in March 2006 was visible along the coast.

Live coverage of the IRIS launch can be seen on NASA Television, beginning at 6 p.m. Thursday. Live audio and briefings will be available on the “V” circuits that can be dialed at 321.867.1220, 1240, 1260.

Col. Keith Balts, 30th Space Wing commander, will be the launch decision authority for the mission.

“I experienced several launches in my role as vice-commander here in the past, but I am looking forward to my first launch as wing commander,” Balts said in a statement. “Our team and launch partners are once again working together to provide access to space with another successful mission.”

The Pegasus will ignite its first stage five seconds into its fall, according to NASA. The second stage, which has no wings, will ignite 94 seconds into flight, and the IRIS will be delivered into its orbit about 10 minutes after launch.

“IRIS will show the solar chromosphere in more detail than has ever been observed before,” said Adrian Daw, deputy NASA project scientist. “My opinion is that we are bound to see something we didn’t expect to see.”

According to NASA, Thursday’s launch will be the last for the Pegasus rocket because no other small spacecraft missions fit the Pegasus niche.

Noozhawk staff writer Gina Potthoff can be reached at Follow Noozhawk on Twitter: @noozhawk, @NoozhawkNews and @NoozhawkBiz. Connect with Noozhawk on Facebook.