No one is completely sure where President Trump plans to take Americans in space — not even NASA.

But Bill Nye has a few suggestions.

Last year, the nonprofit space-exploration advocacy group he runs, the Planetary Society, drew up a 16-page report for the president's transition team offering suggestions about how it should run the nation's space agency.

Now Nye is sharing that report, and a video message to the president, with the rest of the world. The report lists several recommendations for the future of space travel, but the main message is straightforward. Nye wants Trump to keep NASA on the path it's on, with the goal of getting humans to Mars by 2033.

Casey Dreier, director of space policy for the Planetary Society, told the Verge that the decision to make the report public was a response to all the uncertainty about the president's space goals. Trump hasn't nominated anyone to run NASA yet or picked a science adviser. But he has hinted at interest in a return to the moon. Last month, NASA's acting administrator called for a study on the feasibility of adding astronauts to the first test flight of the agency's new rocket and crew capsule, which will orbit Earth's only natural satellite.

“One of the reasons we just put this out is because we have heard those rumors,” Dreier said. “We don’t want NASA to shift again and put the majority of its resources into a lunar program. These shifts don’t turn on a dime.”

“We strongly recommend against starting over,” Nye says in his video message. That's what happened the last time a president took office: Barack Obama shut down George W. Bush's Constellation program, which was headed for the moon, and asked NASA to instead look toward Mars. There's no way NASA could maintain missions aimed at the moon and Mars simultaneously, the report says, and a lunar landing would inevitably push back the timeline for Mars even further.

So the Planetary Society report urges that NASA orbit Mars first — something that could happen in 2033 — then land astronauts on the surface later in the decade. This can happen if NASA's budget grows to match inflation, the report says (something that hasn't always been the case in the past several years), and if funding responsibilities for the International Space Station are gradually handed over to private space flight companies.

The report also urges Trump to spend about 30 percent of NASA's budget on science programs, including Earth-observing and planetary science missions.

The most optimistic recommendation is saved for last: Nye wants Trump to increase NASA's budget by 5 percent per year over the next five years — enough to match inflation and give the space agency a bit extra to spend. This seems unlikely. Historically, NASA's budget rises and falls with overall non-defense domestic spending, and Trump has pledged to enact major cuts.

But people who work in space exploration have always been a little pie in the sky. It's the nature of the business.

“You have the opportunity to provide clear direction to our nation's space program,” Nye tells Trump in the video. “The advances and discoveries made on your watch could be historic.”

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