SpaceX trained the Inspiration4 crew in largely the same way it has trained NASA crews.

To prepare themselves for the rigors of spaceflight, the crew members were swung around a large centrifuge at the National Aerospace Training and Research Center in Pennsylvania, simulating the forces they will experience during launch and re-entry into the atmosphere at the end of the mission.

They also made trips in a plane that flies in giant arcs that allow the occupants to feel as if they are in zero-gravity for about half a minute. (Gravity does not turn off; rather, the plane dives at the same rate as the people inside are falling, providing them the illusion that they are floating.)

The four went camping on Mount Rainier in Washington State, part of a team-building exercise organized by Mr. Isaacman.

While the Crew Dragon capsule is automated and usually flies itself, the Inspiration4 crew nonetheless underwent much of the same training as NASA astronauts to handle situations if something goes wrong. That included spending 30 continuous hours in a Crew Dragon simulator.

Mr. Isaacman said the hardest part was the deluge of technical information dumped on them.

“It was a little bit of death by PowerPoint for a couple weeks,” he said during Tuesday’s news conference. “But then it immediately went into kind of the more fun phase where now you’re taking all that knowledge that you’ve accumulated and you’re putting it to practical use.”

The 30-hour-long simulation turned out to be a highlight, not an ordeal.

In weekslong simulations of missions to Mars and the moon that Dr. Proctor had participated in previously, “Sometimes, you know, there’s a crew member you might want to kick out,” she said. “But in this case, there wasn’t any of that. We live together. We operate it together. We have fun together, and it really just made me want to do it again and it got me so excited for when we do it up in orbit.”