Also aboard will be some items from “Sesame Street”: Cookie Monster’s cookie, Ernie’s rubber ducky and Grover’s cape, part of a collaboration between NASA and the children’s television program to promote science and math education.

After the flight test, NASA’s progress for future astronaut missions will be slow, hemmed in by tight federal budgets and competing visions of the agency’s future. Orion’s next flight, also without people aboard, is not expected until 2018, and the first ride for astronauts would not occur until at least 2021.

“We feel really fortunate to be in the budget plan, a bipartisan agreement on the budget plan, and our job is to execute to that plan,” Mr. Geyer said. “Yeah, I wish we could go faster, but I think this is a good plan.”

The next destination is also unclear. NASA is pursuing the idea of capturing a small asteroid and taking it to the neighborhood of the moon, and astronauts would then fly in Orion to the asteroid to take a look. NASA officials contend that this “asteroid redirect” mission would be within its budget and would develop technologies necessary for the eventual trip to Mars.

Some skeptics have questioned whether Orion, originally part of a program started under President George W. Bush to send astronauts back to the moon, is even necessary, or a waste of billions of dollars.

The Obama administration canceled Orion and the entire moon program as too expensive and too far behind schedule. But many members of Congress disagreed, and NASA revived a stripped-down version of Orion to be used as a lifeboat for the International Space Station, then resumed a design very close to what had been canceled.

NASA also started work on a heavy-lift rocket known as the Space Launch System that will carry Orion on future launchings. Together, the rocket and the capsule are estimated to cost $19 billion to $22 billion.