Elon Musk told NASA astronauts’ kids, ‘we’ve done everything we can to make sure your dads come back ok’ ahead of the SpaceX launch

SpaceX founder Elon Musk (left) speaks with NASA astronaut Bob Behnken on the fixed service structure of Launch Complex 39A at Kennedy Space Center in Cape Canaveral, Florida, on March 1, 2019.Joel Kowsky/NASA

SpaceX CEO Elon Musk seemed to get emotional on Wednesday when discussing the astronauts his company is about to launch into space.

Speaking on NASA live TV just two hours before the scheduled liftoff, Musk said he felt responsible for the astronauts who are now inside his company’s spacecraft, the Crew Dragon. They are slated to launch at 4:33 p.m. ET, headed for the International Space Station.

“I felt it most strongly when I saw their families just before coming here,” Musk said, pausing for a few seconds and appearing to choke up before continuing. “I said, ‘We’ve done everything we can to make sure your dads come back ok.'”

The astronauts’ safety is the “the only priority” for the SpaceX team during the mission, Musk told “CBS This Morning,” adding that aspects of the mission had given him sleepless nights.

Elon Musk, Vice President Mike Pence, NASA Administrator Jim Bridenstine, and the families of astronauts Bob Behnken and Doug Hurley talk ahead of launch at the Kennedy Space Center, in Cape Canaveral, Florida, May 27, 2020.Joe Skipper/Reuters

“I’m the chief engineer of this thing, so I’d just like to say that if it goes right, it’s credit to the SpaceX-NASA team. If it goes wrong, it’s my fault,” Musk said.

The responsibility, he said, was “really all I can think about right now.”

“I have to kind of mentally block it because otherwise it would be emotionally impossible to deal with,” Musk added.

But he expressed confidence in his company’s technology and the safety of the mission.

“The spacecraft and the rocket have gone through literally thousands and thousands of tests and reviews,” he said, calling Falcon 9 “a well-proven rocket.”

NASA estimates a 1-in-276 chance of crew loss

NASA astronauts Bob Behnken (left) and Doug Hurley wear their spacesuits during a dress rehearsal on May 23, 2020, ahead of NASA’s SpaceX Demo-2 mission to the International Space Station.SpaceX via Twitter

On Saturday, NASA told Business Insider that it estimates a 1-in-276 chance the flight could be fatal and a 1-in-60 chance a problem would cause the mission to fail (but not kill the crew).

The risk to the mission is therefore considered about 4.5 times the risk to the crew. This is in part because of SpaceX’s advanced emergency-abort system, which a January demonstration proved it could fly the Crew Dragon spaceship to safety, away from a doomed Falcon 9 rocket. SpaceX has also worked to limit the risk that space junk, asteroid and comet dust, and other debris might pose to a mission.

For their part, Behnken and Hurley have accepted the risk calculated by NASA and SpaceX.

“I think we’re really comfortable with it,” Behnken told Business Insider on Friday.

Behnken and Hurley are strapped into their seats on the Crew Dragon, May 27, 2020.NASA via Youtube

Behnken added that since he and Hurley have worked with SpaceX on Crew Dragon for roughly five years, they’ve gained more insight into the ways the mission could fail “than any crew has in recent history, just in terms of understanding the different scenarios that are at play.”

Estimations of the odds that the mission could fail are based on computer models that lean on real flight data. SpaceX has launched its latest Falcon 9 rocket dozens of times, generating measurements that can be fed into simulations. The company has also completed a full (uncrewed) test flight of its new Crew Dragon vehicle and about 20 flights of its Cargo Dragon spaceship.

“Its evolution has become more and more safe as it’s been operated, and that’s something that we really do appreciate,” Behnken said. “It’s just remarkable to see all the other missions that have contributed to the human spaceflight program by, in some sense, being a test mission for us before we had the chance to fly on the Falcon 9.”

You can find livestream broadcasts of the launch here.