KENNEDY SPACE CENTER, Fla. — Despite the success of Orion’s first test flight, the program’s manager said that the next Orion test flight was now all but certain to slip from late 2017 to 2018.

“We have a lot of challenges to December of ’17,” Orion program manager Mark Geyer said at a briefing here Dec. 2, referring to the current official date of the second Orion test flight, designated Exploration Mission (EM)-1. “We won’t be there in December of ’17.”

While Geyer has previously suggested that NASA would be challenged to have Orion ready for EM-1 by December 2017, his comments were the strongest indication that the launch will slip to some time in 2018. He said a revised launch readiness date would come after the completion of reviews in the spring of 2015.

One reason for the slip, Geyer said, was the decision to perform the Exploration Flight Test (EFT)-1 mission, where an uncrewed Orion launched on a Delta 4 Heavy rocket Dec. 5 and made two orbits of Earth before splashing down in the Pacific. That flight tested many of Orion’s key subsystems, including its heat shield, electronics and parachutes.

“We learned a ton about getting it done,” Geyer said of EFT-1, “but it took us a little bit longer than we expected.”

Geyer said that bringing the European Space Agency into the program to develop Orion’s service module has also contributed to delays. “They’re doing a terrific job coming up to speed, but their delivery schedule will also push us past December” of 2017, he said.

The December 2017 date for EM-1 was already in doubt after NASA completed in August a Space Launch System review known as Key Decision Point C (KDP-C). That review concluded that there is a 70 percent chance SLS will be ready for the EM-1 launch no later than November 2018.

After the briefing, Geyer said the Orion program is in the midst of its own KDP-C review. “That will go into the spring,” he said, and will incorporate the results of the EFT-1 mission. He said he expects the review to be completed in May.

Like the SLS review, the Orion KDP-C review will include cost and schedule estimates to the 70 percent confidence level, Geyer said. Those estimates will run through the first crewed Orion flight, called Exploration Mission 2 and scheduled for 2021, but will include estimates for EM-1 as well.

At the briefing, Geyer declined to give an estimate of the cost of the overall EFT-1 mission. He said NASA is spending about $370 million for the launch as well as Orion components that will not be recovered and reused. That estimate, though, does not include the cost to build the Orion command module itself, which will be refurbished after the mission and reflown on a test of the spacecraft’s launch abort system in 2018.

Geyer explained that the cost of building the Orion spacecraft flying on EFT-1 is wrapped into the overall estimates for the cost of Orion design, development, test and evaluation, or DDT&E. “We don’t split out DDT&E costs by flights. We don’t calculate it that way,” he said.