Full Breakdown
NASA Halts Development of Second Mobile Launch Platform for SLS
4/6/2026, 11:20:56 AM
NASA's Decision on Mobile Launcher 2
NASA has officially ceased work on the Mobile Launcher 2 (ML-2), a second launch platform intended for the Space Launch System (SLS) Block 1B rocket, which the agency has decided not to develop. During a briefing on March 29, Shawn Quinn, manager of NASA’s Exploration Ground Systems program, announced the stop-work order, indicating that hardware from ML-2 will be repurposed as spare parts for the existing Mobile Launcher 1, which supports the SLS Block 1 used in the Artemis 1 and 2 missions. Quinn noted that critical components, such as the umbilical arms for the core stage and the Orion spacecraft, will be preserved for future use.
Background on the SLS and ML-2
The SLS Block 1B was designed to utilize a larger Exploration Upper Stage, necessitating a different launch platform than the one used for the smaller Interim Cryogenic Propulsion Stage (ICPS) of the Block 1. However, on February 27, NASA announced a shift in strategy, opting for a "near Block 1" version of the SLS to increase the frequency of upcoming missions. This decision also included plans to replace the ICPS with a version of the Centaur upper stage.
Financial and Operational Challenges
The development of ML-2 faced significant financial and scheduling issues. NASA awarded a $383 million cost-plus contract to Bechtel in 2019, with an initial completion date set for March 2023. However, a 2024 report from NASA’s Office of Inspector General projected that the total cost could reach up to $2.5 billion, with the platform potentially not being operational until 2029. Former NASA Administrator Bill Nelson criticized Bechtel for underbidding the contract, which he claimed led to performance issues.
Review of Mobile Launcher 1 After Artemis 2
Following the successful launch of Artemis 2 on April 1, NASA is assessing the performance of the Mobile Launcher 1. The platform sustained more damage than anticipated during the Artemis 1 launch in 2022, prompting repairs to various components, including tubing and elevators. Quinn stated that lessons learned from Artemis 1 informed improvements to the platform, such as stronger blast doors and enhanced water spray systems to mitigate exhaust residue damage. Initial assessments indicate that the damage from Artemis 2 is primarily cosmetic, with Lori Glaze, NASA's acting associate administrator for exploration systems development, reporting positive results compared to the previous mission.
Criticism & Opposition
Critics have raised concerns regarding the management of the SLS program and the decision to halt ML-2's development. The significant cost overruns and delays have led to scrutiny of NASA's contracting practices and project oversight.
Verbatim Quotes
- “We pivoted the team to begin removing some of the hardware that is common on Mobile Launcher 1 that we can use as critical spares,” — Shawn Quinn, NASA Exploration Ground Systems Program Manager
- “Because Bechtel underbid on a cost-plus contract in order to, what appears, to get it,” — Bill Nelson, Former NASA Administrator
- “Overall, everything is looking pretty good, especially when compared to Artemis 1.” — Lori Glaze, NASA Acting Associate Administrator for Exploration Systems Development
