WASHINGTON — NASA will spend nearly $1 billion on a mobile launch platform for the Space Launch System that will be used for no more than four launches, a NASA report released March 17 revealed.

The report by NASA’s Office of Inspector General (OIG), the second in as many weeks about NASA’s exploration programs, blamed both changing NASA requirements and poor performance by one contractor for the issues with the Mobile Launcher 1 (ML-1) platform, and that a second platform may also face cost and schedule problems.

The ML-1 platform, which will be used for the assembly, transport and launch of the SLS, was originally built for the Constellation program at a cost of $234 million. NASA decided to modify ML-1, designed for the smaller Ares 1 rocket, for the SLS after a NASA study determined that would be cheaper than either modifying a shuttle mobile launch platform or building a new one.

That study estimated that modifying ML-1 for SLS would cost just $54 million, but by the time the agency developed a formal cost estimate for that work in 2014, the cost had increased to $384.7 million. Even after that formal estimate, the cost continued to grow, with NASA now estimating it will reach $692.8 million. That includes $30 million of work to be performed in 2020 through 2022 to prepare it for the first crewed launch, Artemis 2.

“Unanticipated design and construction problems were the primary drivers behind the ML-1 project’s cost and schedule increases,” OIG stated in the report. Part of the reason was “immature or undefined SLS and Orion requirements” that required changed to the design. “NASA’s finalization of requirements late in the development cycle resulted in significant rework of the ML-1 structure and key components such as the umbilicals that interface with SLS and Orion.”

Another issue was poor coordination among several contractors involved in the design and construction work on ML-1. NASA, OIG concluded, “had no comprehensive process to incorporate work from the different contractors into a single master design.” In one case mentioned in the report, NASA had to spend $1.8 million to reroute cryogenic piping in the way of ducting used by an environmental control system and move other piping to mitigate leaks.

The report also singled out one contractor, Vencore, responsible for subsystem designs for ground support equipment and other services. NASA selected the company, which already did a range of work at the Kennedy Space Center, “because they provided the most flexibility and affordability,” the report stated.

However, OIG said that Vencore suffered from high employee turnover and relied on a small number of subject matter experts, which “contributed to its design errors and slow response when correcting mistakes.” Vencore was taken off the ML-1 project in 2017 because of its poor performance, although the company received ratings ranging from “good” to “excellent” on its cost-plus contract for the ML-1 work.

NASA addressed some those issues when setting up the ML-2 project to build a second mobile launch platform for use by the Block 1B version of SLS. That effort, projected to cost $486 million, will use a single contractor, Bechtel, to handle both the design and construction of the platform. That will allow the company to be more involved in the design process and offer more cost-effective approaches.

However, OIG warned that ML-2 could still face cost and schedule challenges, in part because of the potential for changes in the design of the Exploration Upper Stage (EUS) used by the SLS Block 1B. “Although NASA expects fewer changes for ML-2 than during development of ML-1 due to the second launcher’s design-build approach, ML-2 will likely experience changes such as those that may be required as the new EUS design matures,” the report states.

The use of a cost-plus contract for ML-2, the report added, also provides limited motivation for the contractor to reduce costs. The report cited as evidence both the experience with Vencore on the ML-1 project as well as Boeing on development of the SLS core stage, which has suffered years of delays.

NASA, in a response included in the report, accepted four recommendations by OIG, including identifying any immature technical requirements for ML-2 that could pose cost and schedule risks and to set up an “agency baseline commitment” for the cost of the new platform.

The report noted that, when including original construction costs from the Constellation program, NASA will have spent $927 million on the ML-1 platform. NASA currently expects to use the platform only for the first three Artemis missions as well as, potentially, the launch of the Europa Clipper mission, before retiring it as it shifts to the SLS Block 1B and its ML-2 platform.