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(CNN) -- NASA on Thursday morning hopes to enjoy one of its biggest moments since the shuttle era ended in 2011 -- if it can get some kinks worked out.

The space agency's new Orion spacecraft is scheduled to lift off on an uncrewed test flight from Space Launch Complex 37 at Cape Canaveral, Florida. But some delays have so far kept it on the launch pad.

The launch, initially set for 7:05 a.m. ET, was delayed for various reasons, including wind gusts, a boat coming too close to the launch area, and a failure of some fuel valves to close in the booster rockets, NASA said.

Mission managers hope to launch the craft before the day's window closes at 9:44 a.m. ET.

"We haven't had this feeling in awhile, since the end of the shuttle program," Mike Sarafin, Orion flight director at Johnson Space Center, said in a preflight briefing on Wednesday. He said it's the beginning of something new: exploring deep space.

Orion -- NASA's next giant leap

Orion -- NASA's next giant leap

Orion -- NASA's next giant leap

Orion -- NASA's next giant leap

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NASA's next giant leap