NASA has decided it must delay the maiden flight of its Space Launch System rocket, presently scheduled for November 2018, until at least early 2019. This decision was widely expected due to several problems with the rocket, Orion spacecraft, and ground launch systems. The delay was confirmed in a letter from a NASA official released Thursday by the US Government Accountability Office.

"We agree with the GAO that maintaining a November 2018 launch readiness date is not in the best interest of the program, and we are in the process of establishing a new target in 2019," wrote William Gerstenmaier, chief of NASA's human spaceflight program. "Caution should be used in referencing the report on the specific technical issues, but the overall conclusions are valid."

The GAO report referenced by Gerstenmaier, NASA Human Space Exploration: Delay Likely for First Exploration Mission, reveals a litany of technical concerns, such as cracking problems in the core stage of the Space Launch System rocket, that have significantly reduced the "margin" in the schedule available to accommodate development delays.

The GAO strongly recommended that NASA publicly acknowledge the likelihood of a delay and give Congress a more reasonable launch readiness date for Exploration Mission-1 (EM-1), the first full-up launch of the SLS rocket and Orion spacecraft. NASA would do this by September 30, Gerstenmaier said. Delaying the first SLS launch further may prove politically painful for NASA. Congress directed NASA to build the SLS rocket in 2010 and wrote a law requiring an initial test flight by the end of 2016. The agency may now miss that deadline by at least three years.

More complications

NASA's position is complicated by several factors, most notably a request from the Trump administration to demonstrate some kind of crewed flight by the end of the new president's first term in 2020. Under NASA's existing plan for EM-1, the agency sought to launch the SLS rocket with an uncrewed Orion vehicle (and unfinished life support systems) by late 2018. Then, crew would fly on the second launch of SLS (EM-2) with a finished version of Orion in 2021 or later. However, the White House has asked NASA to look at the possibility of adding crew to EM-1.

The space agency has been studying this possibility for the last couple of months, and its report on such missions should be publicly released within a couple of weeks. In making the decision to fly crew on the initial launch of SLS, the agency would not only be taking on additional risks in terms of crew safety, it would also be dealing with additional costs, perhaps $1 billion or more in total.

After NASA releases this report, the White House and Congress will begin the process of setting the agency's budget for fiscal year 2018, which begins on October 1 of this year. Out of these negotiations, a new plan for the SLS rocket and Orion spacecraft will likely result. What we now know for sure is that any launch in 2017 is definitively off the table.