NASA Administrator Bill Nelson has praised Tesla Inc TSLA chairman Elon Musk for the incredible rise of SpaceX in the private space industry, although they have been written off by critics.

What happened: Nelson recently told news week that the space industry has benefited from what SpaceX has already achieved. He even hinted that there’s a lot more to come from the Musk-led company — a notion that was “busted” by most in the company’s early days.

“When there was the beginning of space for cargo and crew [programs]the two serious bidders were SpaceX and Boeing, and they all screwed SpaceX and said, ‘Oh, Boeing is an old company,'” Nelson said.

“Well, guess who, after their first test flight with astronauts, will make their sixth flight, and guess who’s still on the ground?”

NASA ended its space shuttle program in 2011, relying on Russia for trips to the International Space Station. A few years later, NASA awarded large contracts Boeing Co B.A and SpaceX to again rely on the US for rocket missions.

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Since then, SpaceX has launched several NASA-funded manned missions while Boeing has yet to carry people in its capsule to the International Space Station.

Early last year, NASA selected SpaceX for development Human Landing System for his Artemis III mission, aimed at returning astronauts to the moon. NASA’s Orion capsule is expected to remain in orbit around the moon while SpaceX’s spacecraft descends to the lunar surface. Starship will then return the astronauts to orbit, where they will be taken to the Orion capsule for a journey back to Earth.

Nelson reportedly told Newsweek that SpaceX is currently “on track” with human landing system development.

“I’m a huge fan of what these commercial companies have not only done but are going to do,” Nelson said before mentioning Amazon.com, Inc AMZN Blue Origin.

“Well I want blue…