Elon Musk has suggested that NASA should move the workforce associated with the Space Launch System (SLS) to other parts of the economy, arguing that repurposing these workers would be a better outcome than sustaining the multibillion-dollar rocket program.

In a post on X on Tuesday, Musk responded to criticism regarding the costs of the SLS, stating, “It would be better to repurpose the workforce to other parts of the economy.” His comments come as renewed scrutiny focuses on the financial burden of the agency’s Moon rocket.

The cost of the SLS program has been a subject of debate. A 2021 estimate from NASA’s Office of the Inspector General (OIG) indicated that flying one SLS/Orion system through Artemis IV would average approximately $4.1 billion per launch. This figure encompasses the rocket, Orion spacecraft, European Service Module, and ground operations, with the OIG estimating production costs for the SLS itself at about $2.2 billion per mission.

The retention of the SLS workforce is linked to historical directives. The Government Accountability Office (GAO) noted in 2012 that the 2010 NASA Authorization Act required the agency to leverage investments and workforce from the Space Shuttle and Constellation programs for the development of SLS. The NASA OIG later stated that this mandate led the agency to retain Shuttle-era systems, infrastructure, and contracts.

Boeing Co. (NYSE: BA) is identified as the contractor for the SLS core stage, with the GAO noting its contract is of the cost-plus-award-fee type. The OIG has previously stated that NASA underestimated the complexity of adapting heritage engines and boosters.

Musk previously reacted to an OIG estimate that the Artemis IV mobile launcher could cost $2.7 billion. The post he was replying to contrasted the SLS with SpaceX’s reusable Falcon Heavy, which the company states can carry 63.8 metric tons to low Earth orbit.

Despite the criticism, policy is shifting. The Trump administration’s fiscal 2026 NASA budget proposal calls for an “orderly phase out” of SLS after Artemis III and the use of commercial transportation services for later Artemis missions. However, NASA continues to press forward with current missions, including Artemis II, which carried astronauts around the Moon in April, and the assembly of the Artemis III vehicle for a 2027 crewed demonstration mission.