SpaceX Polaris Dawn launch postponed after helium leak

“Teams are taking a closer look at a helium leak at the bottom of the Quick Disconnect umbilical,” Elon Musk's company wrote on X. Umbilicals connect a tower to a rocket, while helium is a non-flammable gas commonly used to pressurize fuel lines.

On board a Falcon 9 rocket, SpaceX's Dragon capsule is expected to reach an altitude of 1,400 kilometers – higher than any manned mission since the Apollo era, i.e. in the last 50 years.

Mission Commander Isaacman will lead his four-person team through the heart of the mission: the first commercial spacewalk, equipped with sleek, newly developed extravehicular activity (EVA) suits from SpaceX.

Rounding out the team are mission pilot Scott Poteet, a retired U.S. Air Force lieutenant colonel; mission specialist Sarah Gillis, a senior aerospace engineer at SpaceX; and mission specialist and medical officer Anna Menon, also a senior aerospace engineer at SpaceX.

The quartet completed more than two years of training in preparation for this groundbreaking mission, completing hundreds of hours of simulators, skydiving, centrifuge training, scuba diving and climbing an Ecuadorian volcano.

Polaris Dawn is scheduled to be the first of three missions in the Polaris program, a collaboration between Isaacman, founder of technology company Shift4 Payments, and SpaceX.

“The idea is to develop and test new technologies and operations to advance SpaceX's bold vision of enabling humanity to travel to the stars,” Isaacman said at a recent press conference.

Isaacman declined to disclose his total investment in the project, although reports suggest he paid around $200 million in September 2021 for SpaceX's Inspiration4 mission, the first all-civilian orbital mission.

Polaris Dawn will reach its highest altitude on the first day, briefly penetrating the Van Allen radiation belt, a region teeming with high-energy charged particles that can pose a health threat to humans over extended periods of time.

The crew will reach the ISS in an orbit almost three times higher than that of the International Space Station, but will still remain far from the record distance of over 408,000 kilometers reached by the Apollo 13 crew in 1970.

The Apollo 13 astronauts flew this long distance to orbit the far side of the moon in a slingshot after their spacecraft was damaged by an explosion, preventing the planned lunar landing from taking place and forcing them to return to Earth without major propulsion maneuvers.

On the third day, the crew will don their state-of-the-art EVA spacesuits – equipped with head-up displays, helmet cameras and advanced joint mobility systems – and take turns to exit their spacecraft in pairs. Each will spend 15 to 20 minutes in space, 700 kilometers above the Earth's surface.

What's notable, however, is that even the couple strapped into their seats will be exposed to the vacuum of space, as the Dragon capsule has no airlock.

The following day is dedicated to testing laser-based satellite communications between the spacecraft and Starlink, SpaceX's constellation of over 6,000 internet satellites aimed at increasing the speed of space communications.

The crew will also conduct nearly 40 experiments designed to improve our understanding of human health during long-duration spaceflight, including tests using contact lenses embedded with microelectronics to continuously monitor changes in eye pressure and shape.

After six days in space, the mission ends with a splashdown off the coast of Florida, where a SpaceX recovery ship is waiting.

The second Polaris mission will also use a Dragon capsule, while the third and final mission will be the maiden flight of Starship, SpaceX's next-generation rocket prototype that will play a key role in Musk's vision of colonizing Mars.