Why SpaceX Polaris Dawn launch will depend on weather forecast - and not only on launch day

Even assuming the Federal Aviation Administration quickly completes its investigation into the SpaceX Falcon 9 booster mishap and clears SpaceX to resume launches, there will be one more thing that needs to go right before the much-anticipated Polaris Dawn mission can launch: the weather.

"The primary factor driving the launch timing for Polaris Dawn is the splashdown weather within Dragon's limits," Mission commander Jared Isaacman posted Thursday on X (formerly Twitter). "Unlike an ISS mission, we don't have the option to delay long on orbit, so we must ensure the forecast is as favorable as possible before we launch."

And the weather forecast is not looking great.

Spectators were left disappointed this week as SpaceX called off the overnight launch for the second night in a row, saying they were standing down at least through Friday.

Originally set to liftoff early Tuesday morning, the launch was delayed 24-hours as SpaceX found a ground-side helium leak. The rocket was lowered, and then put vertically again. The issue was fixed, and it appeared conditions were good for a liftoff very early Wednesday morning. At least, they appeared good on the Space Coast. But SpaceX delayed the launch again, saying it was standing down for two days due to weather.

And then the company proceeded to launch a Falcon 9 Starlink mission from another launch pad, causing many to wonder what was up? Why did weather prevent the Polaris Dawn launch but not Starlink?

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Why weather impacted Polaris Dawn launch but not the Starlink

Polaris Dawn, which will see the first spacewalk done by civilian astronauts, is not your typical space mission.

Unlike the NASA and Axiom crews which also ride to space in SpaceX Dragon spacecrafts, the Polaris Dawn mission is not docking with the International Space Station. Instead, the Polaris Dawn crew will be orbiting Earth. So, there's no safe harbor.

Therefore, the crew is entirely dependent on all the supplies brought with them. The mission is only set to last approximately five days, and with limited supplies onboard, the crew must be ready to land within a certain timeframe.

"Our launch criteria are heavily constrained by forecasted splashdown weather conditions. With no ISS rendezvous and limited life support consumables, we must be absolutely sure of reentry weather before launching," Mission commander Jared Isaacman posted on X (formerly Twitter) after the earlier decision to stand down because of weather.

The weather that caused the concern was in the Dragon splashdown area, which is stated to be off the coast of Florida. Unfavorable weather conditions in the return site could impact the safety of SpaceX recovery crew and the returning Polaris Dawn crew.

Starlink missions, of course, are focused on depositing the satellites in orbit. There's no crew to return.

When Polaris Dawn launches, how long can the crew stay in space?

"Our mission timeline for our flight is five days. We have consumables for about 120 hours. There's also plenty of margin after that, but really, our expected timeline is about 120 hours. If weather degrades, and we need to come home early, we certainly can," Polaris Dawn mission specialist, Sarah Gillis, previously told FLORIDA TODAY.

Polaris Dawn weather outlook: Not ideal conditions

Following the booster landing mishap of the Starlink mission that launched Wednesday morning, the FAA is requiring a public safety investigation. It's still unclear how long it will last or what the ultimate impact will be on Polaris Dawn. SpaceX did not respond to a request for comment.

But Isaacman posted that the crew "remains in quarantine, staying productive, keeping fit, and ready to launch within approximately 30 hours of receiving a favorable forecast."

"Space exploration demands patience, resilience, and teamwork," he said, adding that they were sorry for all those who traveled to watch the launch and have faced the delays.

Will Ulrich, warning coordination meteorologist from the National Weather Service in Melbourne, told FLORIDA TODAY that he's watching a cold front that could interfere with the Polaris launch.

"We've got, actually, an early season cool front that is going to be migrating southward towards the northern Gulf Coast, and that cold front is going to act as a focusing mechanism for inclement weather that's going to include showers and thunderstorms," said Ulrich.

"And so obviously, in terms of recovery conditions that can make things more complicated out in the waters of the Northern Gulf and offshore the Atlantic Ocean. And so we're anticipating generally increasing rain chances in that recovery area as we move into early next week, as that cool front kind of stalls out across the deep south and northern Gulf of Mexico ? looks like through the middle of next week," said Ulrich.

When was the last SpaceX crewed orbital mission?

Most crewed missions head to the space station so weather forecasts focus on launch day.

It's been awhile since we've seen this type of orbital mission. The last crewed mission to only orbit was Inspiration4 in September of 2021 ? the first all-civilian space mission. That mission was also commanded by Isaacman.

Weather was calm and therefore that mission did not see a launch delay.

Brooke Edwards is a Space Reporter for Florida Today. Contact her at [email protected] or on X: @brookeofstars.

This article originally appeared on Florida Today: Weather forecast to play big role in upcoming Polaris Dawn launch