Polaris Dawn launch recap: Live updates from SpaceX liftoff Tuesday from Kennedy Space Center

Launch recap: Scroll down to review live updates from the Tuesday, Sept. 10, liftoff of the Polaris Dawn mission aboard a SpaceX Falcon 9 rocket from NASA's Kennedy Space Center.

Original story: It's finally launch time for the Polaris Dawn mission!

Welcome to FLORIDA TODAY Space Team live coverage of the early morning Polaris Dawn mission from NASA's Kennedy Space Center Press Site.

Citing earlier poor weather, SpaceX is now targeting 5:23 a.m. Tuesday EDT to launch the four-civilian crew aboard a Dragon capsule and Falcon 9 rocket from pad 39A.

The crew's Dragon spacecraft previously flew the Crew-1 and Inspiration4 astronauts into low-Earth orbit. After soaring skyward along a northeasterly trajectory, the Falcon 9's first-stage booster will target landing aboard a SpaceX drone ship out at sea about 9? minutes after liftoff.

However, the Space Force's 45th Weather Squadron only forecasted 40% odds of favorable weather for liftoff, and SpaceX crews are monitoring conditions at possible Dragon splashdown sites at mission's end. Primary concerns include thick cloud layers, cumulus clouds, flight through precipitation and ascent-corridor recovery weather.

Countdown Timer

Dragon separates from Falcon 9 upper stage

Update 5:40 a.m.: The Dragon spacecraft has separated from the rocket's upper stage, SpaceX reported.

SpaceX Falcon 9 booster lands

Update 5:33 a.m.: The Falcon 9 first-stage booster just landed aboard SpaceX's drone ship Just Read the Instructions in the Atlantic Ocean, completing its fourth mission.

Liftoff!

Update 5:23 a.m.: SpaceX has just launched the all-civilian Polaris Dawn crew aboard a Falcon 9 from KSC, kicking off their wide-ranging, five-day orbital mission.

Cape skies clear for SpaceX rocket launch

Update 5:16 a.m.: In a marked change from previous hours, the skies above Cape Canaveral are finally free of significant cloud cover, this National Weather Service radar loop from the Melbourne Orlando International Airport station shows.

Polaris Dawn launch coming up

Update 5:09 a.m.: Thirteen minutes before SpaceX's Falcon 9 liftoff attempt, the countdown appears to be proceeding as planned. Rocket fueling remains well underway at KSC.

Following is a list of key remaining countdown milestones. T-minus:

• 7 minutes: Falcon 9 begins engine chill prior to launch.

• 5 minutes: Dragon transitions to internal power.

• 1 minute: Command flight computer begins final prelaunch checks; propellant tank pressurization to flight pressure begins.

• 45 seconds: SpaceX launch director verifies “go for launch.”

• 3 seconds: Engine controller commands engine ignition sequence to start.

• 0 seconds: Falcon 9 liftoff.

Polaris Dawn launch fans gathering in Titusville

Update 4:59 a.m.: FLORIDA TODAY Space Reporter Brooke Edwards reports launch spectators are gathering in Titusville at Space View Park-Veterans Memorial Park on the Indian River Lagoon shoreline.

SpaceX Falcon 9 fueling now underway

Update 4:51 a.m.: SpaceX just announced Falcon 9 fueling procedures are underway at KSC, and the Dragon's escape system is armed.

That means tonight’s Starlink countdown is now committed to lift off at 5:23 a.m. without any delays, or else today's launch must be postponed.

Polaris Dawn is 'go for launch'

Update 4:40 a.m.: In a brief 4:38 a.m. tweet, SpaceX has confirmed: "Polaris Dawn is go for launch."

SpaceX: Weather odds now 80% 'go for launch'

Update 4:28 a.m.: Odds of favorable launch weather have now increased to 80%, SpaceX radio chatter indicates.

The four Polaris Dawn crew members have been seated inside their Dragon spacecraft for roughly 3? hours. Polaris Dawn officials released a selection of photos of the crew preparing for liftoff.

SpaceX: Weather odds now 65% 'go for launch'

Update 4:13 a.m.: In a change of atmospheric fortune, SpaceX webcast host Kate Tice said odds of favorable weather have jumped up to 65% for the upcoming 5:23 a.m. launch attempt.

Crowds left Titusville parks after launch delay

Update 4:04 a.m.: FLORIDA TODAY Space Reporter Brooke Edwards snapped this photo of illuminated pads 39A and 39B from across the Indian River Lagoon in Titusville shortly after SpaceX announced the nearly two-hour launch delay.

Edwards said numerous spectators left Space View Park-Veterans Memorial Park after the liftoff time switched to 5:23 a.m.

Clouds, rain encroaching Cape Canaveral

Update 3:47 a.m.: National Weather Service radar from the Melbourne Orlando International Airport station shows a lingering cell of clouds and rain over KSC and the Merritt Island National Wildlife Refuge.

SpaceX launch prep underway in Brevard

Update 3:33 a.m.: Brevard County Emergency Management officials have activated the agency's launch operations support team ahead of SpaceX’s upcoming Polaris Dawn launch.

Here's why SpaceX delayed 1st Polaris Dawn try

Update 3:12 a.m.: SpaceX webcaster John Insprucker cited "dynamic conditions" as the meteorological reason the 3:38 a.m. liftoff attempt got pushed back. Insprucker said a shower was passing over the launch pad, but forecasters expected it to dissipate.

"The bigger problem is, there are frontal boundaries north and south of the launch site — and we were then seeing cells popping up. And that made us a little concerned that they may still be around at T-0, and we would then have had to scrub for the day," Insprucker said.

"So the good news is, we are still counting down for launch. We're going to wait two hours and change, and see how things go," he said.

SpaceX pushes back launch to 5:23 a.m.

Update 2:56 a.m.: SpaceX crews are now targeting liftoff at 5:23 a.m. — the first of two backup launch opportunities this morning — because of unfavorable weather. A cell to the northwest is of particular concern.

Will clouds part for Polaris Dawn launch?

Update 2:38 a.m.: This National Weather Service radar loop from the Melbourne Orlando International Airport station shows lingering shoreline cloud cover, stretching from Cape Canaveral and Merritt Island southward to roughly Sebastian Inlet.

SpaceX radio chatter indicates officials will make a launch-weather decision 50 minutes before the 3:38 a.m. target liftoff time.

SpaceX touts new spacesuits, upcoming spacewalk

Update 2:25 a.m.: In a science fiction-esque tweet, SpaceX officials said the new spacesuits that Polaris Dawn will test in orbit feature "a scalable design with the intent to create millions to help make life multiplanetary."

"Designed with mobility in mind, SpaceX teams incorporated new materials, fabrication processes, and novel joint designs to provide greater flexibility, while also incorporating enhancements for reliability and redundancy during a spacewalk," company officials said in a related 2:01 a.m. tweet.

Polaris Dawn day-by-day schedule

Update 2:05 a.m.: Following is a day-by-day breakdown of the Polaris Dawn mission.

• Day 1: Launch, then pass through the inner regions of Earth's Van Allen radiation belt to 1,400 km (870 miles) above the surface. That represents the highest altitude astronauts have reached since Apollo 17, the final moon mission, back in December 1972.

• Day 2: Prepare for spacewalk during a suited "mobility demo;" descend to a 700-km (435-mile) cruising orbit.

• Day 3: Don spacesuits, perform leak checks and conduct spacewalk.

• Day 4: Test a Starlink laser-based communication system.

• Day 5: Prepare for atmospheric reentry.

• Day 6: Reenter Earth's atmosphere and splash down at one of seven sites off the Florida coast in the Gulf of Mexico and Atlantic Ocean.

SpaceX to target booster landing at sea

Update 1:45 a.m.: Crew members have closed the Dragon hatch. This mission marks the fourth flight for this Falcon 9 first-stage booster, which previously launched Crew-8 and two Starlink missions.

Following stage separation, the booster will target landing on the drone ship Just Read the Instructions in the Atlantic Ocean 9 minutes, 35 seconds after liftoff.

Polaris Dawn suit, communication checks done

Update 1:27 a.m.: SpaceX just reported the Polaris Dawn crew seats have rotated inside the Dragon, and suit leak and communications checks are complete.

More Space Force Polaris Dawn forecasts

Update 1:10 a.m.: Should tonight's launch attempt get postponed, the same target times are available Wednesday morning, SpaceX announced.

Looking ahead, the 45th Weather Squadron pegs odds of "go for launch" weather at 40% Wednesday and 50% Thursday. Both dates share the same laundry list of primary meteorological concerns:

• Thick cloud layers.

• Cumulus clouds.

• Flight through precipitation.

• Moderate risk of unacceptable ascent corridor recovery weather.

• Low-to-moderate risk of unacceptable booster recovery weather.

Polaris Dawn crew boards Dragon spacecraft

Update 12:52 a.m.: Crew members are now walking into their Dragon and getting strapped into their seats.

SpaceX video shows Polaris Dawn crew at pad

Update 12:44 a.m.: SpaceX just tweeted this 40-second video featuring footage of the crew members exiting their Teslas near the elevator alongside their Falcon 9 rocket at pad 39A.

Polaris Dawn crew departs suit-up room

Update 12:36 a.m.: The four Polaris Dawn crew members just departed their suit-up room and boarded two dark-colored Teslas for rides to the launch pad.

SpaceX Polaris Dawn webcast begins

Update 12:17 a.m.: The SpaceX Polaris Dawn launch webcast is now posted above, right below the countdown clock.

Polaris Dawn will be Cape's 63rd launch of 2024

Update 11:55 p.m.: Polaris Dawn is slated to become the 63rd orbital launch of the year thus far from KSC and neighboring Cape Canaveral Space Force Station. The most recent was SpaceX's Starlink 8-11 mission Thursday morning from the latter.

The all-time annual record from Florida's Space Coast is 72 launches, which was just set last year.

Space Force launch forecast details

Update 11:35 p.m.: Details from the 45th Weather Squadron's Polaris Dawn launch forecast, which describes Florida's "stagnant weather pattern which is expected to last through most of the week."

"Low level flow will be light and variable while west-southwesterly flow aloft will keep afternoon and evening rain chances high with storms favoring the east side of the peninsula. Though chances will be highest during the day, the threat for occasional showers and storms will continue through the overnight hours, including for the primary and backup launch windows early Tuesday and Wednesday morning," the forecast said.

"However, the main threat will be the Thick Cloud Layers Rule as mid and upper level clouds stream across the Spaceport in the very saturated atmosphere created by the stalled boundary," the forecast said.

Polaris Dawn commander: 'Game time'

Update 11:15 p.m.: A little more than two hours ago, Polaris Dawn mission commander Jared Isaacman tweeted a simple two-word message: "Game time."

For the latest news and launch schedule from Cape Canaveral Space Force Station and NASA's Kennedy Space Center, visit floridatoday.com/space.

Rick Neale is a Space Reporter at FLORIDA TODAY. Contact Neale at [email protected]. Twitter/X: @RickNeale1

Space is important to us and that's why we're working to bring you top coverage of the industry and Florida launches. Journalism like this takes time and resources. Please support it with a subscription here.

This article originally appeared on Florida Today: Polaris Dawn launch recap: Live updates from NASA's Kennedy Space Center