While NASA struggles against delays, the agency finally seems to be accepting that a late 2020 maiden SLS launch is increasingly unlikely. The first break from NASA’s stated deadline came from an agency official who expressed concern that the launch could slip to the middle of 2021.

Speaking at the International Symposium for Personal and Commercial Spaceflight (ISPCS) on October 10, NASA’s acting associate administrator for human exploration and operations, Ken Bowersox explained that the agency’s SLS schedule “is very, very aggressive.”

The current schedule requires a completed core stage to be shipped to the Stennis Space Center in Mississippi for a static-fire test referred to by the agency as “the Green Run.” If the test is completed successfully, the stage will be refurbished and then shipped to the Kennedy Space Center for integration with its upper stage, two solid-rocket boosters and an Orion spacecraft.







If every element of this process goes according to plan, the first SLS rocket could be on a pad for the launch of Artemis 1 by the end of 2020. However, if there is a delay in even the smallest step, that date would be impossible.

“We have a chance to actually have a rocket on the pad and launch by the end of next year,” said Bowersox. “But when you start throwing all those different uncertainties, it’s more likely that we will move out into 2021.”

For months NASA administrator Jim Bridenstine has attempted to find alternatives and workarounds for the increasingly unreasonable schedule. In March, Bridenstine proposed launching the Artemis 1 mission aboard a commercial launch vehicle, an idea that was strongly opposed by congress. Just months later, Bridenstine proposed skipping the Green Run test altogether, a move that would save several months. This was, however, rightly opposed by several parties including the Aerospace Safety Advisory Panel.

Bowersox’s comments at ISPCS are the first sign that NASA is ready to accept that a late 2020 maiden SLS flight is just not possible.