Report: Congressional analysts worry SpaceX engines are prone to cracks

Enlarge / A draft of a forthcoming GAO report raises concerns about turbopumps in the Falcon 9's Merlin engines. (credit: SpaceX)

A draft of a US Congressional report into NASA's commercial crew program has found technical problems with both SpaceX and Boeing's efforts to provide transport to the International Space Station. However, according to the Wall Street Journal, the forthcoming report from the US Government Accountability Office focuses most closely on issues with turbopumps in SpaceX's Falcon 9 rocket.

The newspaper says the report has found a "pattern of problems" with the turbine blades within the turbopumps, which deliver rocket fuel into the combustion chamber of the Merlin rocket engine. Some of the components used in the turbopumps are prone to cracks, the government investigators say, and may require a redesign before NASA allows the Falcon 9 booster to be used for crewed flights. NASA has been briefed on the report's findings, and the agency's acting administrator, Robert Lightfoot, told the newspaper that he thinks “we know how to fix them.”

A spokesman for SpaceX, John Taylor, said the company already has a plan in place to fix the potential cracking issue. "We have qualified our engines to be robust to turbine wheel cracks," Taylor said. "However, we are modifying the design to avoid them altogether. This will be part of the final design iteration on Falcon 9." This final variant of the Falcon 9 booster, named Block 5, is being designed for optimal safety and easier return for potential reuse. According to company founder Elon Musk, it could fly by the end of this year.