NASA Marshall Space Flight Center (MSFC) Director Jody Singer said today that the agency is reassessing the 2020 launch readiness date for Exploration Mission-1 (EM-1), the first launch of Space Launch System (SLS) with an uncrewed Orion capsule. SLS was an excepted activity during the 35-day partial government shutdown so work did not stop and significant progress is being made, but NASA wants to ensure the system is ready before attempting the first launch.

Speaking at a Space Transportation Association (STA) meeting on Capitol Hill today, Singer outlined how much has been accomplished to date. All the segments for EM-1 are ready except the core stage, which is “almost ready,” but much testing remains. The “Green Run” all-up system test at Stennis Space Center will take place late this year or early next, she said.

The FY2019 Consolidated Appropriations Act allocated $2.15 billion for SLS. That includes $150 million for the Exploration Upper Stage (EUS). An additional $48 million is provided for a second mobile launch platform. EM-1 does not need either of those, however. Language in the report requires them to be ready by 2024. That is the nominal date for the EM-3 mission to deliver a habitation module to lunar orbit for the Gateway.

Sen. Richard Shelby (R-AL), chairman of the Senate Appropriations Committee, represents MSFC, in Huntsville. He introduced Singer by noting that as committee chairman he has “more than a passing interest” in what NASA does and a “parochial” interest as well. He told Singer to “keep doing what you’re doing” and “we’ll keep funding you.”

Singer described SLS as “America’s rocket” because more than 1,100 companies in 44 states are involved in building it, supporting more than 32,000 jobs and producing $6 billion in economic benefit. It is needed for deep space exploration, delivering segments of the lunar-orbiting Gateway “which is needed for safe access to the Moon and beyond.”

The initial version of SLS, Block 1, will be able to place 70 metric tons (MT) of mass into low Earth orbit. That will use an Interim Cryogenic Upper Stage (ICPS). Future versions using EUS will increase the capacity to as much as 130 MT, more than the Saturn V rocket that sent Apollo astronauts to the Moon.

SLS is controversial because companies such as SpaceX and Blue Origin are developing or planning to develop their own large rockets, raising the question of why the government needs to spend tax dollars to build SLS instead of buying services from those companies. SLS advocates insist that the government must ensure it has the capabilities it needs and not rely on businesses that could abruptly change or cancel their plans.