(CNN) – SpaceX's latest mission, a daring and daring journey into Earth's Van Allen radiation belts with a crew of four civilians who will also attempt the first commercial spacewalk, has just taken off.
The mission, dubbed Polaris Dawn, lifted off from NASA's Kennedy Space Center in Florida at 5:23 a.m. Eastern Standard Time Tuesday.
The launch comes after several weather delays in late August and early Tuesday morning hampered the Polaris Dawn crew's efforts to get off the ground.
As the countdown clock struck zero, SpaceX's Falcon 9 rocket roared to life, sending a blinding fire and deafening explosion across the launch site at NASA's Kennedy Space Center in Florida.
The crew rode atop the rocket, strapped inside an igloo-shaped SpaceX Crew Dragon capsule measuring about 13 feet (4 meters) at its base, as the rocket glided away from the clutches of Earth's gravity.
The mission, dubbed Polaris Dawn, was scheduled to lift off at 3:38 a.m. Eastern Time on Tuesday. Due to poor weather on the launch pad, SpaceX has decided not to launch at its first opportunity Tuesday morning, but will try again at the second scheduled time. The new launch time is 5:23 a.m. Eastern Time.
“Due to unfavorable weather conditions at the launch site, the target is now 5:23 am ET for Falcon 9 to deliver the @PolarisProgram Polaris Dawn mission into orbit,” SpaceX published on X.
At the time of the time change, no propellant had yet been loaded into the rocket.
It was previously reported that if the weather did not cooperate for the 5:23 a.m. opportunity, there would be another opportunity at 7:09 a.m. Eastern Time.
SpaceX livestreamed the event on X, the social media platform formerly known as Twitter that SpaceX CEO Elon Musk acquired in 2022.
This launch attempt comes after several issues hampered the Polaris Dawn crew's efforts to lift off in late August. First, a problem with ground equipment at the launch site delayed the planned date by 24 hours, and then weather forecasts forced SpaceX to scrap two more attempts.
Around the same time, a Falcon 9 — the type of rocket that powered Polaris Dawn into space — malfunctioned during a routine satellite mission, prompting federal regulators to briefly ground all Falcon 9 rockets from flying. SpaceX received permission on Aug. 30 to put the Falcon 9 back in flight.
To further complicate launch prospects, SpaceX not only needs clear weather for the mission to lift off, but must ensure that the waters and winds are calm when the crew returns from space after their five-day excursion. The timing of their return could be critical. Since conducting a spacewalk will deplete oxygen reserves, the Polaris Dawn mission will only have enough life support for five or six days in space.
By 2½ minutes into liftoff, the lower portion of the Falcon 9 rocket, called the first stage, will have expended most of its fuel. At that point, the first stage will separate from the rocket's second stage while the upper stage ignites its engine and continues to propel the Crew Dragon spacecraft at faster speeds.
Meanwhile, the Falcon 9 first stage will be guided back to Earth to land on a sea platform where it can be refurbished and used again on future missions. It's a signature move by SpaceX that the company says helps reduce the cost of rocket launches.
To enter Earth’s orbit, the Falcon 9 rocket will need to reach more than 17,000 miles per hour, or “orbital velocity.” Once it reaches that desired speed, the Crew Dragon spacecraft will separate and must navigate the vacuum of space using only its onboard thrusters for the remainder of the mission.
Polaris Dawn is the brainchild of SpaceX and Jared Isaacman, the billionaire founder of fintech company Shift4 Payments, which made its first foray into spaceflight with the Inspiration4 mission in September 2021.
This flight, however, is no walk in the park.
Isaacman and his crewmates — which include close friend and former U.S. Air Force pilot Scott “Kidd” Poteet, as well as SpaceX engineers Anna Menon and Sarah Gillis — hope to achieve several records on the mission.
First, SpaceX's capsule aims to carry the crew to a record height for an orbit around Earth, surpassing the milestone set by NASA's Gemini 11 mission in 1966, which reached 1,373 kilometersIf successful, Polaris Dawn will beat that record by about 20 miles.
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Polaris Dawn's spaceflight would also be the highest by a human since NASA's Apollo program, which ended in 1972 and took 24 astronauts a quarter-million miles to the moon instead of stopping in Earth orbit.
Polaris Dawn could also be the furthest space mission ever undertaken by a woman.
To kick off the third day of this mission, the civilian crew, while orbiting at a lower altitude of about 700 kilometers above Earth, will attempt a historic spacewalk.
The endeavor will be dangerous, as it will expose the four crew members and the interior of Crew Dragon to the vacuum of space. This situation can make it difficult to close the vehicle's hatch due to pressure differences. In addition, exposure to the vacuum can lead to the release of toxins from equipment when the cabin is repressurized, although SpaceX says it has taken steps to prevent this.
