“I really do see this as a renaissance in human space transportation,” Phil McAlister, director of NASA’s commercial spaceflight division, said before the launch, alluding to the commercial nature of the journey, with the crew of four flying aboard a privately built spacecraft in a trip SpaceX will oversee. It’s the first of several private spaceflights that Elon Musk’s Space Exploration Technologies Corp. is planning in coming years, with the next scheduled for early 2022.

In addition to serving as a proof-of-concept demonstration flight, the mission will also raise $200 million in charity for childhood-cancer research. Beyond the undisclosed sum Isaacman is paying SpaceX for the flight — reported as $200 million by Time magazine — he has also pledged $100 million to St. Jude Children’s Research Hospital in Memphis, Tennessee.

As the countdown to liftoff neared zero, Isaacman could be heard saying, “Punch it, SpaceX.”

The three-day trip will take the foursome deeper into space — 360 miles (575 kilometers) — than any flight since the last Hubble telescope servicing mission in May 2009 aboard the Space Shuttle Atlantis. The Hubble orbits about 340 miles above Earth.

NASA played no role in the trip planning beyond some technical consultations and training assistance for the crew.

Isaacman, 38, founder and chief executive officer of payment processor Shift4 Payments Inc., assumed the role of mission commander. Also flying in the capsule are:

• Hayley Arceneaux, 29, a childhood-cancer survivor who works as a physician’s assistant at St. Jude. She is also the first person to fly to space with a prosthetic device: She lives with a rod implanted in her left leg as part of her treatment for bone cancer.
• Sian Proctor, 51, a geoscience professor in Phoenix and a finalist for the 2009 NASA astronaut class.
• Chris Sembroski, 42, an Air Force veteran who works as an engineer for Lockheed Martin Corp. in Seattle.

SpaceX designed the flight and determined that the crew were trained and fit to go. The four spent about nine months in preparation, including learning about the Dragon’s systems, how to intervene during the flight if necessary, and other endeavors such as practicing in a centrifuge to withstand high-gravity forces. They also flew several times in a fleet of former military fighter jets Isaacman owns to become accustomed to G forces.

The Inspiration4 commander also mandated a multi-day hike in May, above 10,000 feet, on Mount Rainier in Washington State.

SpaceX, which ferries NASA astronauts to and from the International Space Station with the Dragon vehicle, will share data from the mission with the agency, including the capsule’s encounters with space debris and radiation, McAlister said. NASA engineers will also inspect the spacecraft’s heat shield after the crew’s return.

In another first, SpaceX now has three Dragons in orbit simultaneously — Inspiration4 and two that are attached to the space station.

Orbital Altitude

The orbital altitude has been a source of debate between SpaceX and Isaacman, who is shown in a Netflix documentary produced about the flight pressing for an altitude higher than the space station during an early meeting at the company’s California headquarters. The station’s altitude is about 255 miles.

A detailed risk analysis concluded that the vehicle would have enough fuel at the higher altitude, carbon dioxide management and food and other supplies, SpaceX’s human spaceflight director, Benjamin Reed, said at the briefing. The Dragon is configured to remain in orbit for a week if needed, Isaacman tweeted Tuesday.

“If we’re going to go to the moon again and we’re going to go to Mars and beyond we’ve got to get a little bit outside of our comfort zone and take that next step in that direction,” Isaacman said.