NASA has delayed the first flight of its Space Launch System (SLS) heavy-lift rocket and Orion crew capsule by over a year, to December 2019, an agency official said Nov. 9.

While a recent NASA review made the case for an even longer delay, to June 2020, “the agency has chosen to manage to a December 2019 launch,” said William Gerstenmaier, NASA’s associate administrator for human exploration and operations. “This earlier launch date is reasonable and challenges the teams to stay focused on tasks without creating undue pressure.”

Artist's illustration of NASA's Space Launch System (SLS). Photo: NASA.
Artist’s illustration of NASA’s Space Launch System (SLS). Photo: NASA.

NASA announced in May that it was delaying the unmanned flight, known as Exploration Mission-1 (EM-1), from November 2018 to sometime in 2019 due to production problems, including welding glitches, and weather-related damage to key facilities.

The European Space Module (ESM), which the European Space Agency (ESA) is developing to provide propulsion and life support to Orion, has had its own difficulties, and NASA and ESA are working to ensure ESM does not cause more delays in EM-1, said Gerstenmaier, who testified before the House Science, Space and Technology Committee’s space panel.

ESA has committed extra funding to ESM, and NASA is helping a U.S. supplier fix problems making valves for the module. In addition Lockheed Martin [LMT], Orion’s prime contractor, plans to send technicians to Europe to help with ESM manufacturing.

Gerstenmaier said ESM’s delivery, which is scheduled for April 2018, might slip a month or two and that NASA is fashioning work-arounds to avoid an overall program delay.

“We’re doing everything we can,” he told lawmakers. “It’s really just this first-time manufacturing that’s causing us the problems.”

During EM-1, Orion will travel for up to 25 days, going beyond the Moon before returning to Earth. It will also deploy CubeSats to study lunar water and ice, a near-Earth asteroid and radiation levels.

The first crewed flight, EM-2, is now slated to occur in 2023. It had been previously scheduled for August 2021.

Gerstenmaier also testified that NASA is writing a human exploration roadmap, as required by the fiscal year 2017 NASA authorization act, and intends to send a report on it to Congress next month. The report will, among other things, describe potential international participation, he said.