Starship lunar lander
A lunar lander proposed by SpaceX and based on its Starship vehicle is one of three concepts selected by NASA for its Human Landing System program. Credit: SpaceX

WASHINGTON — A NASA evaluation suggests that the agency selected SpaceX for one of the three human lunar lander awards as a high-risk, high-reward option that could provide significant capability but may not be ready in time for a 2024 landing.

According to a NASA source selection statement for the Human Landing Services (HLS) program, dated April 28, SpaceX had the weakest adjectival rating of the three companies selected, with technical and managerial ratings of “Acceptable.” Blue Origin received a technical rating of Acceptable and a managerial rating of “Very Good,” while Dynetics received technical and managerial ratings of Very Good.

SpaceX received several strengths based on the proposed capabilities of the Starship vehicle it bid, a spacecraft much larger than the other winning proposals. The system “meets or exceeds all of NASA’s threshold values” for functional and performance requirements, the document states.

The design also supports NASA’s long-term lunar exploration plans, where the agency has emphasized sustainability and longer stays on the lunar surface. “By immediately incorporating these capabilities into its proposed design, SpaceX’s proposal provides substantial mission design flexibility and dramatically reduces the time and cost associated with transitioning into sustainable phase mission operations,” the document states.

That approach, though, carries with it risks. NASA cited as a strength a development plan that “prioritizes early and numerous ground and flight system demonstrations to reduce schedule and technical risk.” That test program ranges from a flight of Starship in low Earth orbit to an uncrewed lunar landing in 2022.

However, NASA noted lengthy delays in other SpaceX programs, such as commercial crew and development of the Falcon Heavy rocket, which were years behind original schedules. “These delays decreased the [Source Evaluation Panel’s] confidence in SpaceX’s ability to successfully execute on its proposed HLS development schedule,” the document stated.

Steve Jurczyk, NASA associate administrator and the source selection authority for the program, downplayed that weakness. “I find that SpaceX’s extensive relevant experience, combined with the lessons learned from these efforts, somewhat mitigate the risk associated with the potential for schedule delays,” he wrote.

Evaluators also considered as a weakness SpaceX’s concept of operations, which involves using other Starship vehicles as tankers and a propellant depot to fuel the Starship that will serve as the lander. That approach “requires numerous, highly complex launch, rendezvous, and fueling operations which all must succeed in quick succession in order to successfully execute on its approach,” which evaluators argued posed a risk to a 2024 landing.

A third weakness in the SpaceX proposal involved development of its propulsion system, which is “notably complex and comprised of likewise complex individual subsystems that have yet to be developed, tested and certified with very little schedule margin to accommodate delays.” SpaceX’s development plan, evaluators concluded, “does not adequately address the risk of potential delay in development, as well as concomitant delay to SpaceX’s demonstration mission.”

NASA also cited weaknesses in the propulsion systems of the other two awardees. NASA said that Blue Origin’s power and propulsion system is relatively complex and immature, posing development risks. “Technically, the design appears to be sound, but this design can only come to fruition as a result of a very significant amount of development work that must proceed precisely according to Blue Origin’s plan, including occurring on what appears to be an aggressive timeline,” the document stated.

The agency had a similar criticism of the propulsion system in the Dynetics lander. “This system is complex and relies upon technologies that are at relatively low maturity levels or that have yet to be developed for Dynetics’ proposed application, but would need to be developed at an unprecedented pace,” it said.

Jurczyk, though, balanced that risk with the innovative approach that combines the ascent and descent modules into a single element, ringed by a set of fuel tanks. “Thus, while I agree that Dynetics’ power and propulsion system overall presents substantial technical and schedule risk, it is also the case that its approach is exactly the kind of innovative solution that NASA sought through the HLS solicitation,” he concluded.

Both Blue Origin and Dynetics, which had no significant weaknesses beyond their propulsion systems, won praise for their partnership approaches. Blue Origin’s “national team,” which features Draper, Lockheed Martin and Northrop Grumman, is “a team with a successful record of relevant past performance across numerous efforts that have direct implications for their performance of this effort, and greatly increases NASA’s confidence” in successfully developing the lander.

The Dynetics team includes about 25 companies, including Maxar, Sierra Nevada Corp. and Thales Alenia Space. NASA cites Dynetics’ small business subcontracting plan as a significant strength, saying it “appreciably exceeds the solicitation requirements in a way that will be advantageous to the Government during contract performance and beyond.”

Jeff Foust writes about space policy, commercial space, and related topics for SpaceNews. He earned a Ph.D. in planetary sciences from the Massachusetts Institute of Technology and a bachelor’s degree with honors in geophysics and planetary science...