• The Polaris Dawn mission, an ambitious five-day journey to the upper reaches of Earth's orbit, will take the crew higher than an human has traveled in more than 50 years.
• After descending to a cruising altitude of 435 miles above Earth, the crew will also attempt the first-ever spacewalk made by anyone other than government astronauts.
• The mission is intended to allow the crew to test SpaceX technology that could set the stage for future deep space exploration, including crewed trips to Mars.

Update: The launch of the Polaris Dawn mission has been scrubbed "due to unfavorable" weather for the return landing, SpaceX said Tuesday night. No new launch date has yet been scheduled.

Four civilians comprising the trailblazing Polaris Dawn crew are about to embark on a daring cosmic mission that includes the first-ever spacewalk made by anyone other than government astronauts.

The ambitious venture will be under the command of none other than billionaire entrepreneur Jared Isaacman, the man behind another historic commercial mission in 2021 that marked the first time an all-civilian crew went to space. Isaacman and his crew arrived last week at NASA's Kennedy Space Center in Florida to finalize preparations for the launch, which SpaceX now says is targeting for no earlier than Wednesday morning.

Ahead of the crew is a daunting journey to the upper reaches of Earth's orbit, where they will spend five pivotal days performing tests that could set the stage for future deep space exploration before splashing down into the ocean on day six.

Here's what to know about Polaris Dawn, its potentially historic mission and its intrepid crew.

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What is the Polaris Dawn mission?

Polaris Dawn is far from simply a billionaire-funded joyride to space.

While in orbit, Isaacman and the crew will endeavor to make history while testing space technology on behalf of SpaceX that could prove crucial as NASA and other space agencies set their sights on destinations like Mars.

The objectives for the crew's five-day stay aboard a SpaceX Crew Dragon capsule include:

• Reach altitudes higher than any human has traveled since NASA’s Apollo lunar program came to an end in the 1970s: The Dragon will tread a path that will take the crew high enough for the vehicle to travel through the treacherous Van Allen radiation belt 870 miles from Earth's surface – or more than three times higher than the International Space Station.
• Attempt to become the first-ever private citizens to conduct a spacewalk while 435 miles above Earth: Two crewmembers will open the hatch and exit the spacecraft while wearing Extra-Vehicular Activity (EVA) suits designed by SpaceX. But because the Dragon does not have an airlock, its entire interior will be exposed to the vacuum of space, meaning all four astronauts will wear the suits to receive oxygen through tethers.
• Conduct nearly 40 scientific experiments and test a new laser-based satellite communication system using Starlink – all while using the publicity to raise funds for St. Jude Children’s Research Hospital.

On the sixth day of the mission, the SpaceX vehicle will reenter Earth's atmosphere and splash down at one of seven sites off the Florida coast.

"We hope the results from our mission will accelerate SpaceX’s vision to make life multiplanetary," Isaacman said in a statement. "Throughout our mission, we will aim to inspire humankind to look up and imagine what we can achieve here on Earth and in the worlds beyond our own.”

Polaris Dawn launch date: How to watch takeoff

The four-member crew of Polaris Dawn are scheduled to embark no earlier than Wednesday on their Earth orbit mission.

The SpaceX Crew Dragon capsule that will carry them into orbit will lift off atop a Falcon 9 rocket.

The launch was delayed Tuesday to give ground crews time to take “a closer look at a ground-side helium leak” on a piece a equipment designed to detach from the rocket during takeoff, SpaceX said on X.

If another mission scrub is necessary, the launch could still take place Thursday morning, according to SpaceX.

SpaceX will stream the launch via X, formerly Twitter, and the NASA facility sold tickets to watch the launch in person at the Florida base.

FLORIDA TODAY, part of the USA TODAY Network, will also provide live coverage starting about two hours before liftoff at floridatoday.com/space.

What are the Van Allen radiation belts?

The Van Allen belts pose one of the largest hazards to future spacefarers venturing deep into the cosmos.

According to NASA, the belts are two areas of trapped cosmic radiation in the magnetosphere surrounding Earth like "an enormous donut." The outer belt is made up of billions of high-energy particles that originate from the sun, whereas the inner belt results from interactions of cosmic rays with Earth’s atmosphere.

The International Space Station's orbit keeps the outpost safely below the radiation belts, but future astronauts will have to fly through them to reach the moon and eventually Mars.

When the Polaris Dawn crew travels through the radiation belts, their SpaceX craft’s nose will be oriented to minimize the astronauts’ exposure to harmful radiation.

"In the future, if we are going to have (SpaceX) Starships regularly going to the moon or Mars, we are going to have to fly through the Van Allen belts regularly," Isaacman told Florida Today in an email.

Why is it called the Polaris Program?

The space program is named after Polaris, a constellation of three stars more commonly known as the North Star – a guiding navigational light throughout human history.

Who is Jared Isaacman, billionaire behind Polaris Dawn?

Isaacman, a billionaire who helped bankroll the Polaris Dawn mission, won't be watching from the ground when it takes off: The experienced aviator and adventurer from Pennsylvania will be aboard the Dragon capsule and will serve as the mission commander.

Isaacman famously dropped out of high school at 16 years old to start his internet company Shift4 Payments and in recent years has become something of an avid spacefarer.

In 2021, he served as mission commander of Inspiration4, the world’s first all-civilian mission to space that introduced commercial space tourism to the world. The mission, which Isaacman self-funded, saw four civilians head to space for three days in orbit, raising more than $250 million for St. Jude Children’s Research Hospital.

With more than 7,000 flight hours of aviation experience, Isaacman is also an aviation enthusiast who is qualified to fly military fighter jets.

Isaacman said in his email to Florida Today that he didn't expect to go to space again after the Inspiration4 mission.

"I was not planning to go back until after visiting Elon at Starbase in October of 2021," Isaacman said in an email to the outlet.  "At that point, we discussed possibilities for test and development missions that would help move the needle on SpaceX's bigger vision to make life multi-planetary."

Meet the rest of the Polaris Dawn crew

Isaacman will lead a crew that includes a pilot and two mission specialists.

• PilotScott “Kidd” Poteet, a retired United States Air Force lieutenant colonel who flew with the Thunderbirds. Poteet, a native of New Hampshire, previously served as mission director for Inspiration4.
• Mission specialist Sarah Gillis, a Colorado native who is a lead space operations engineer at SpaceX, where she is responsible for overseeing the company’s astronaut training program. Gillis trained the Inspiration4 astronauts.
• Mission specialist and medical officer Anna Menon, a SpaceX lead space operations engineer who served in mission control during multiple crewed missions. Menon, of Houston, has written a children’s book, "Kisses from Space," which was inspired by her experience preparing for the Polaris Dawn mission and her desire to share her spaceflight experience with her two young children. She plans to read it from space during the mission.

What's next for the Polaris Program?

Polaris Dawn is the first of three human spaceflights under the Polaris Program, all of which are intended to test SpaceX technologies needed to carry humans deep into the cosmos.

The second mission "will continue to expand the boundaries of future human spaceflight missions, in-space communications, and scientific research," according to the program's website. Additional details, including a launch date, have not yet been announced.

When the day comes that the third and final Polaris Program mission launches, it's intended to be the first human spaceflight on the SpaceX Starship rocket. The gargantuan rocket, which has so far only undergone uncrewed tests, will one day ferry NASA astronauts from lunar orbit to the moon's surface as part of the space agency's Artemis program.

Contributing: Brooke Edwards, Florida Today

Eric Lagatta covers breaking and trending news for USA TODAY. Reach him at [email protected]