SpaceX launched its historic Polaris Dawn mission on Tuesday, an audacious orbital expedition that will catapult civilians into a high-radiation region of space and see them attempt the first-ever spacewalk by non-professional astronauts.

Led by Shift4 Payments CEO Jared Isaacman, the four-member crew aims to journey farther into the cosmos than any other manned mission in more than half a century, since the end of the Apollo era.

On the mission's first day, they will soar to a peak altitude of 1,400 kilometers before returning into a lower orbit.

"Dragon will travel repeatedly through the orbital altitudes of over 10 thousand satellites and bits of space debris," SpaceX founder CEO Elon Musk wrote on X. "No room for error in our calculations."

The highlight of the voyage is slated for as early as Thursday: the first ever spacewalk by civilians, outfitted in sleek, newly developed SpaceX extravehicular activity (EVA) suits with heads-up displays, helmet cameras and an advanced joint mobility system.

Since the Crew Dragon capsule lacks an airlock, the entire crew will be exposed to the vacuum of space for the duration of the spacewalk, as two venture out, tethered to the spaceship.

"I think the world is a more interesting place when you can journey among the stars," Isaacman said in a video message released by SpaceX.

"We will develop technologies and test technologies that will help SpaceX ultimately achieve its long-term ambitions of making human life interplanetary."

The capsule blasted off early Tuesday atop a Falcon 9 rocket from the Kennedy Space Center in Florida.

Applause broke out across the mission control center as it separated successfully from the main engine and the first glimpses of Earth came into view.

Musk joined in the celebrations, a photo reposted by him on X showed.

At its upper altitudes, the capsule will enter the Van Allen radiation belt, a region teeming with high-energy charged particles that can pose health risks to humans over extended periods. (AFP)