When NASA announced the completion of the Space Launch System's critical design review Oct. 22, it also released an updated illustration of the rocket, with the core stage now orange instead of white. NASA said in a press release that orange is "the natural color of the insulation that will cover those elements," as was the case with the shuttle's external tank. Not explained in the release, those, are the curved gray and orange stripes on the solid rocket boosters. Some think they are intended to evoke memories of the shuttle itself or the logo of original shuttle contractor Rockwell International — or, perhaps, computer game company Atari. Credit: NASA

WASHINGTON — NASA has decided it will not add astronauts to the first flight of the Space Launch System, a launch now delayed until some time in 2019.

In a media teleconference May 12, agency leaders said that while it was technically feasible to place a crew on the Exploration Mission (EM) 1 flight of SLS and Orion, cost, schedule and risk issues led NASA and the White House to decide to keep with current plans to fly the mission without astronauts.

“At the end of the day, we found it technically feasible to fly crew on EM-1, as long as we had a commitment of additional resources and schedule,” NASA Acting Administrator Robert Lightfoot said. However, after assessing what it would take to implement that plan, officials “decided that, while it was technically feasible, they really reaffirmed that the baseline plan we had in place was the best way for us to go.”

That decision, Lightfoot said, was made jointly by NASA and the White House. “We definitely sat with them after we heard the feasibility study and came to this conclusion together,” he said. He added that the new administration has been “incredibly supportive” of the study and NASA’s overall exploration plans.

NASA announced Feb. 24 that it had started a study to examine the feasibility of putting astronauts on EM-1. That study stemmed out of discussions with the agency review team, or “landing team,” assigned to NASA by the incoming Trump administration after the November election, particularly after concerns that technical issues could delay the planned November 2018 EM-1 launch.

Bill Gerstenmaier, NASA associate administrator for human exploration and operations, said that the study turned up fewer technical issues with putting a crew on EM-1 than he originally expected. “What I was surprised by was that I thought there would be a whole lot of really negative work that would actually maybe make this not very attractive to us,” he said.

“But when Robert and I look at this overall, it does add some more risk to us, because it’s the first crew on the vehicle,” he said. The work to add crew to EM-1 would have cost NASA an additional $600–900 million, and delay the launch likely to the first or second quarter of 2020.

“The culmination of changes in all three of those areas said that overall, probably the best plan we have is actually the plan we’re on right now,” Gerstenmaier said. “When we looked at the overall integrated activity, even though it was feasible, it just didn’t seem warranted in this environment.”

NASA also confirmed in the announcement that, even by keeping EM-1 uncrewed, the launch date would be delayed to some time in 2019. NASA had effectively stated that in a response to a U.S. Government Accountability Office report published April 27 that had concluded it was unlikely NASA could launch the mission in November 2018 as planned.

Gerstenmaier said a variety of issues with SLS and Orion contributed to the delay to 2019. “The fact that we’re running into some production problems is typical of almost any major development of this complexity,” he said. He added that the tornado that damaged the Michoud Assembly Facility in New Orleans in early February “really set us back in a big way.”

Most recently, a dome section of a liquid oxygen tank being built for SLS qualification tests was damaged at Michoud May 3. “It’s probably not repairable,” Gerstenmaier said. Other tank domes are available to use in its place, he said.

“This was a significant event for us,” Gerstenmaier said, but one he said will likely not have a major effect on the overall schedule.

NASA has not announced a more specific launch date for EM-1 yet other than 2019. Gerstenmaier said the agency would wait until a mishap investigation board at Michoud concludes its study of the tank accident. “We’re probably a month or two away from coming up with a final schedule,” he said.

The EM-1 delay could also push back EM-2, the first mission to carry a crew. That mission will also use an upgraded version of the SLS with the more powerful, and larger, Exploration Upper Stage, which requires some reconfiguration of ground systems at the Kennedy Space Center.

“We’ve been carrying, tentatively, an August 2021 date for EM-2,” Gerstenmaier said. “It will probably move somewhere to the right because of the relationship between EM-1 and EM-2.” A revised date for EM-2, he said, should come several months after the new date for EM-1.

Lightfoot also said that, contrary to statements made by President Trump in an April 24 call with astronauts on the International Space Station, there’s been no push by the White House to accelerate NASA human spaceflight plans, including humans to Mars by the end of a potential second term for the president.

“We continue to have a good dialogue with the White House. The administration has been very supportive of our plan,” he said. “They have not asked us to go to Mars by 2024.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...