SpaceX fires up Falcon 9 rocket ahead of Polaris Dawn astronaut launch (photos)

Update for 9 p.m. ET on Aug. 26: SpaceX has delayed the Polaris Dawn launch until no earlier than Aug. 28 due to a helium leak. Read our story here .

SpaceX's historic Polaris Dawn astronaut mission remains on track to lift off early Tuesday morning (Aug. 27).

Over the weekend, SpaceX briefly ignited the first-stage engines of the Falcon 9 rocket that will launch Polaris Dawn , in a common preflight test known as a static fire.

"Static fire test of Falcon 9 complete — targeting Tuesday, August 27 at 3:38 a.m. ET for launch of the @PolarisProgram's Polaris Dawn mission," the company said on X on Sunday (Aug. 25) morning. Later that day, SpaceX shared two photos of the test in another X post.

Polaris Dawn will launch from Pad 39A at NASA's Kennedy Space Center in Florida, sending four people into orbit aboard a SpaceX Crew Dragon spacecraft. The company will stream the liftoff live.

If all goes according to plan, the Polaris Dawn crew — commander Jared Isaacman, pilot Scott "Kidd" Poteet and mission specialists Sarah Gillis and Anna Menon — will get farther from Earth than any people have since the Apollo era. Isaacman and Gillis will also perform a spacewalk , the first ever conducted on a private spaceflight.

Related: SpaceX 'go' to launch private Polaris Dawn spacewalk mission on farthest human spaceflight since Apollo

— Polaris Dawn mission: Meet the crew taking 1st commercial spacewalk

— SpaceX Polaris Dawn private spacewalk mission: Live updates

— How SpaceX's historic Polaris Dawn private spacewalk will work

Isaacman has been to orbit before. He also commanded and funded the groundbreaking Inspiration4 mission, a three-day journey flown by SpaceX in September 2021.

Polaris Dawn is the first of three planned missions in the Polaris Program, a human-spaceflight effort organized and funded by Isaacman. The third mission in the series will be the first-ever crewed flight of SpaceX's Starship megarocket, if all goes according to plan.