When it flies for the second time in 2021, NASA’s Space Launch System heavy-lift rocket will indeed launch a crew, the outgoing head of the agency’sand Orion programs said.
Exploration Mission (EM)-2, as NASA calls the planned flight to a distant lunar retrograde orbit, “will be crewed,” Dan Dumbacher, NASA’s deputy associate administrator for exploration systems development, said during a Washington luncheon.
SLS will launch a crewed Orion “despite what some people might want to say in the blogosphere,” Dumbacher said.
The veteran NASA manager, who is leaving the agency July 1, was referring to stories published in May after an executive with Boeing, the agency’s main SLS contractor, said the vehicle’s second mission might be an uncrewed shakedown for a new Exploration Upper Stage that — in Boeing’s baseline plan — would use four RL-10 engines.
Dumbacher would not say whether NASA had committed to building the Exploration Upper Stage, which Virginia Barnes, SLS program manager at Boeing Space Exploration, described as the successor to the Boeing-provided Interim Cryogenic Propulsion Stage, a single-engine stage NASA has baselined for the 2021 SLS flight, and the rocket’s 2017 maiden flight.
“Our baseline plan … is the [Interim Cryogenic Propulsion Stage] on EM1 and EM2,” Dumbacher said June 11. “We are looking at the [Exploration Upper Stage] and when we can bring it into the program — what’s the best place to do it. We don’t have any declarative answers on how we’re doing that just yet, because we’re still working it internally.”
Part of that internal work, said Dumbacher, is making sure the new upper stage is certified to fly a crew the first time it is used on a future SLS configuration.
Dumbacher added that NASA remains on schedule to launch SLS for the first time in late 2017. The rocket would send an empty Orion space capsule, built by, to the same distant lunar retrograde orbit that is planned for the 2021 mission.
Of all the elements of scheduled SLS-Orion missions, the Lockheed Martin-built crew capsule appears likeliest to put the project behind schedule, Dumbacher said.
“Orion’s got challenges,” said Dumbacher. “We’ve had some standard hardware development kind of things that we’ve had to work through with supply chains and other things, and frankly, the budget issues that we had back in  when sequestration was on the table, we had to power back the program a little bit to account for that.”