An independent report published Thursday had troubling findings about the money spent by the agency on propulsion for the Space Launch System rocket. Moreover, the report by NASA Inspector General Paul Martin warns that if these costs are not controlled, it could jeopardize plans to return to the Moon. //

"The agency’s reliance on cost-plus awards increases its financial risk," Martin wrote. "In our judgment, NASA has used cost-plus contracting structures for its SLS booster and engine contracts to a greater extent than warranted. Although the SLS is a new vehicle, its heritage boosters and RS-25 engines are well-established."

Cost-plus contracts pay the recipient the total amount of their costs plus a fee. This is in contrast to the fixed-price contracts NASA has given SpaceX and Blue Origin for landers, the design of which is much more experimental and cutting-edge in nature than repurposing space shuttle hardware. //

For example, the current cost of manufacturing a new RS-25 main engine—which will be used for the Artemis V mission and onward—is about $100 million. NASA and Aerojet are trying to achieve a 30 percent cost savings by the end of this decade, bringing the cost down to $70.5 million. //

Compared to the private sector, even getting the cost of an RS-25 engine down to $70.5 million is a preposterously high price. Blue Origin manufactures engines of comparable power and size, the BE-4, for less than $20 million. And SpaceX is seeking to push the similarly powerful Raptor rocket engine costs even lower, to less than $1 million per engine.

Based on all of the new data in his latest report, Martin said his office has had to revise its estimate of the total cost of a Space System Launch, inclusive of ground systems and the Orion spacecraft. It is now $4.2 billion.