U.S. Sen. Richard Shelby said today the commercial space companies NASA is relying on for access to the International Space Station are behind schedule, possibly unsafe and wouldn't be in the astronaut business without NASA's investment.

Shelby also signaled support for more money to NASA in 2018, including more for the science programs the Trump White House wants to cut. He commented in remarks prepared for today's NASA budget review by the Senate Appropriation Subcommittee on Commerce, Justice, Science and Related Agencies. Shelby chairs that subcommittee.

Shelby blasted the "growing sentiment that NASA should change the way it does business: that is should be a buyer of commercial transportation services. Were it not for billions in development funds from NASA acting as venture capital, there would be no companies attempting to one day take crews to the space station."

Shelby represents Alabama, where NASA's Space Launch System is being developed, and he praised the new rocket as a "versatile platform" to deliver science missions and astronauts.

Even with NASA's investment, Shelby said, "The companies NASA will use for commercial crew services are behind in schedule, the program has increased in cost, and independent observers cite the inability of our partners to meet contracted safety standards."

NASA in 2014 awarded contracts worth $6.8 billion to Boeing and SpaceX to transport astronauts to and from the space station. Those flights may happen in 2018, but could be delayed to 2019.

The Trump administration has proposed a 2018 budget of $19.1 billion for NASA, which is a 2.9 percent cut from this year. That's less reduction than proposed for many other agencies but "still reflects a significant reduction of $561 million," Shelby said.

Shelby said Trump's budget "attempts to navigate a challenging fiscal environment" and understandably represents "a snapshot in time" with decisions based on the best information available then. But he said NASA must have a budget that meets the challenges it's been given.