In Brief
When Elon Musk first talked about landing a rocket engine on a barge floating on the sea, retired U.S. astronaut Scott Kelly was skeptical. After SpaceX did it, Kelly was convinced never to doubt what Musk said again, including his recently unveiled plans for Mars.

Walking the Talk

Now retired, U.S. astronaut Scott Kelly is a veteran of four space flights. He holds the record for total accumulated days in space, as well as for the longest single mission by an American: a full year aboard the International Space Station (ISS). He clearly knows a thing or two about what’s possible in the realm of space flight, and he just told the world he doesn’t doubt Elon Musk when the SpaceX CEO shares his seemingly impossible plans.

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“When Elon Musk said he was going to launch his rocket and then land the first stage on a barge, I thought he was crazy,” Kelly said on Tuesday during an interview with CNBC’s Squawk Box. “And then he did it. I’m not going to ever doubt what he says, ever again.”

During the interview, Kelly spoke about Musk’s revamped plans for getting to Mars aboard a redesigned BFR, the 42-engine rocket SpaceX unveiled during the 2017 International Astronautical Congress (IAC) held in Australia last month. The astronaut says he doesn’t doubt Elon Musk will have the technology ready in five years to launch the BFR.

Rocket Man

Kelly didn’t focus solely on Mars during the interview; he also commented on Musk’s plans to use the BFR for commercial travel on Earth. The retired astronaut believes that regular and safe commercial space transportation will happen within the next 30 years or so.

“I think at first what we’ll have is something similar to the early days of aviation, where the barnstormers took people for rides, and that developed into a transportation system,” Kelly said, before adding, “The more we do it, the better we get at it.” Kelly told CNBC he believes traveling from Los Angeles to London in just 45 minutes in a real possibility.

SpaceX isn’t the only company working toward suborbital space travel. Commercial space tourism is supposedly the forte of Sir Richard Branson’s Virgin Galactic and Amazon’s Jeff Bezos with Blue Origin. Bigelow Aerospace is working on commercial space travel, as well.

In any case, while Kelly doesn’t doubt Elon Musk will be able to follow through on building the technology needed to get to Mars or to travel quickly between Earth’s major cities, he does know firsthand that space can have a dramatic effect on the human body. He studied that impact during his year-long stay aboard the ISS, noting, “In this weightless environment, we lose a lot of bone mass and muscle mass.” If we want to take trips to Mars, we’ll need to find ways to combat these effects, said Kelly.