SLs core stage at Stennis
The core stage of the first SLS being installed on a test stand at the Stennis Space Center earlier this year. Work on the SLS there is suspended as the center moved to Stage 4 of NASA's pandemic response plan. Credit: NASA/SSC

WASHINGTON — NASA now expects the first launch of the Space Launch System to take place in late 2021, with the coronavirus pandemic at least partially contributing to the latest delays.

Speaking at a May 14 meeting of the NASA Advisory Council’s Human Exploration and Operations Committee, Tom Whitmeyer, NASA assistant deputy associate administrator, said the agency would announce as soon as next week that the launch readiness date for the Artemis 1 mission has slipped to late 2021.

“We’re feeling fairly comfortable that we will be having the Artemis 1 mission towards the end of next year,” he said. He declined to be more specific about the date, citing the upcoming formal announcement by the agency of the launch date.

A slip to late 2021 is not surprising. Speaking at a workshop in late February, Steve Jurczyk, NASA associate administrator, said the agency was projecting the first SLS launch would take place in the “mid to late ’21 timeframe” as NASA completed a review of the schedule for the mission.

That assessment came before the coronavirus halted many NASA activities, including SLS testing. NASA’s Stennis Space Center in Mississippi effectively closed in mid-March as it went to Stage 4, or the highest level, of the agency’s pandemic response plan because of COVID-19 cases in the community and with at least one Stennis employee. That stopped preparations for a “Green Run” static fire test of the SLS core stage underway at the time.

After nearly two months, work is slowly starting to resume at Stennis. In a May 14 statement, NASA said “limited crews” returned to the center this week to check out the SLS test stand and begin preparations for resuming tests. Stennis plans to move down to Stage 3 in the next 30 days, allowing more personnel on site to restart test activities.

It will take some time, though, before full test activities resume, as NASA implements new processes and procedures to be able to have people working on site safely. “We’re slowly bringing people back, in a methodical way, to complete the preparations for the core stage,” Whitmeyer said. “It will take up to this summer before we can have our full complement of people ready to go for the more integrated testing.”

Before the pandemic, NASA had planned to perform the Green Run static-fire test in August, and if that was successful, ship the core stage to the Kennedy Space Center in October. Whitmeyer said NASA is planning a wet dress rehearsal of the static-fire test in mid-summer, followed by the static-fire test in mid-fall, perhaps as late as Thanksgiving. “If we have a successful test, then we’d be looking at late this year or very early next year to deliver the core stage to the Cape.”

That scheduled, he added, also depends on weather conditions that could delay testing, as well as the possibility of problems during the Green Run test. “If we learn something during the test, we’ll take more time to fix whatever we learn during that test,” he said.

Doug Loverro, NASA associate administrator for human exploration and operations, was optimistic that the agency could adhere to that new schedule. “If not for COVID-19, we would be on or ahead of schedule” compared to plans made last year, he said during the meeting. In a presentation to the committee May 13, Loverro said Green Run preparations were about 10 days ahead of schedule when Stennis shut down because of the pandemic.

Testing of the SLS core stage is on the critical path for the Artemis 1 launch. “When we complete a successful hotfire test, that sends a signal to the rest of the system,” he said, specifically, a move into integrating the launch vehicle and Orion spacecraft. Segments of the SLS solid-fuel boosters, currently in storage in Utah, will be shipped to KSC in June so they are ready for stacking and later attachment to the core stage.

He noted that the Orion spacecraft, which returned to KSC after it completed environmental testing at NASA’s Plum Brook Station in March, is wrapping up work. “We’re fundamentally complete,” he said, with the spacecraft soon put into temporary storage until the core stage is ready.

Besides Stennis, Whitmeyer said the Michoud Assembly Facility will soon restart work after also going to Stage 4 in March. That facility will, in the next few days, go down to Stage 3, allowing some work to resume on the core stage for the second SLS as well as Orion hardware for future missions.

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...