What time is the SpaceX Ax-2 private astronaut launch for Axiom Space?

Update for 6:19 pm ET: SpaceX has successfully launched the private Ax-2 astronaut mission to the International Space Station. Read our launch wrap story and see video and photos.

SpaceX is counting down to launch the second all-private mission to the International Space Station today (May 21) and if you're hoping to follow it online, you're going to need to know when it actually lifts off. 

A SpaceX Falcon 9 rocket will launch four astronauts on the Axiom Space Ax-2 mission to the space station from NASA's Kennedy Space Center in Cape Canaveral, Florida. The 10-day mission is commanded by former NASA astronaut Peggy Whitson, with paying customer John Shoffner as pilot and Saudia Arabia's first two astronauts , Ali AlQarni and Rayyanah Barnawi, rounding out the crew. 

You can follow the launch live with our Ax-2 mission updates page and watch the Ax-2 astronaut launch live online. Read on to see what time SpaceX will launch the Ax-2 mission today 

What time is the SpaceX Ax-2 astronaut launch?

The Axiom Space Ax-2 private astronaut crew smiles in their Dragon capsule during launch rehearsal. They are: (from left) Saudi astronaut Rayyanah Barnawi; investor and pilot John Shoffner; former NASA astronaut Peggy Whitson; and Saudi astronaut Ali AlQarni. (Image credit: SpaceX)

SpaceX will launch the Ax-2 mission for Axiom Space at 5:37 p.m. EDT (2137 GMT) from Pad 39A at NASA's Kennedy Space Center, the site used by the company for all of its human spaceflight missions. 

The launch has an "instantaneous window," meaning SpaceX must launch at that time in order to reach the International Space Station on schedule and cannot hold the countdown. If SpaceX has to delay for any reason, the company can try again on Monday, May 22, at 5:14 p.m. EDT (2114 GMT).

Related: Meet the 4 astronauts of Axiom Space's Ax-2 mission

Can I watch the Ax-2 astronaut launch online?

Yes. NASA, SpaceX and Axiom Space will offer a series of live webcasts for the public to follow the Ax-2 launch live. You can watch the SpaceX Ax-2 launch online in a Space.com simulcast of those webcasts. 

SpaceX's webcast will begin around 2:10 p.m. EDT (1810 GMT) and run through liftoff. You can find it at SpaceX's Ax-2 mission page and YouTube channel. The company will also offer an audio-only feed from its launch center in Florida and Mission Control center in Hawthorne, California.

Axiom Space's launch webcast begins at the same time and may be a simulcast. It will stream live at Axiom's YouTube channel. Axiom Space has also said it will provide an Arabic language livestream for Saudi Arabia viewers tracking the launch. 

NASA's webcast will begin at 4:30 p.m. EDT (2030 GMT) and cover the last hour of prelaunch operations and the liftoff. It will be broadcast on NASA's YouTube channel and NASA TV.

How long is SpaceX's Ax-2 astronaut launch?

This diagram of SpaceX's Ax-2 astronaut launch shows the mission's liftoff, Falcon 9 first stage landing and Dragon separation. (Image credit: SpaceX)

From liftoff to spacecraft separation, SpaceX's Ax-2 mission launch should last just under 13 minutes, but the mission itself will last much longer. 

Axiom Space's Ax-2 astronauts will fly a 10-day mission to the International Space Station and are expected to spend eight of those days actually living and working aboard the space station, where they will perform 20 different science investigations amid other tasks and outreach events. It will take 15 hours for the Dragon capsule, called Freedom, to reach the space station on Monday, May 22

SpaceXs final hour before launch includes a series of critical tasks to get the rocket ready to fly. Here's the schedule SpaceX will follow to reach liftoff, including fueling the Falcon 9 rocket with its RP-1 rocket-grade kerosene and liquid oxygen (LOX) propellant.

Related: Ax-2 private astronaut mission will grow 1st stem cells in space

Swipe to scroll horizontally
SpaceX Ax-2 Countdown Timeline
TIME (Hr:Min:Sec)EVENTHeader Cell - Column 2
T-00:45:00Launch director gives "go" for fuelingRow 0 - Cell 2
T-00:42:00Dragon launch escape system armedRow 1 - Cell 2
T-00:35:00RP-1 fueling startsRow 2 - Cell 2
T-00:35:001st stage LOX fueling startsRow 3 - Cell 2
T-00:16:002nd stage LOX fueling startsRow 4 - Cell 2
T-00:7:00Falcon 9 engine chilldown Row 5 - Cell 2
T-00:05:00Dragon on internal powerRow 6 - Cell 2
T-00:01:00Propellant tank pressurization for flightRow 7 - Cell 2
T-00:01:00Command flight computer's final checksRow 8 - Cell 2
T-00:00:45Launch director's final GO for launchRow 9 - Cell 2
T-00:00:03Engine ignition sequence startsRow 10 - Cell 2
T-00:00:00LiftoffRow 11 - Cell 2

One the Falcon 9 rocket carrying the Ax-2 mission lifts off, that's when the 13-minute trip to orbit begins. Here's a rundown of how that will work for this flight, including first and second stage main engine cutoffs (MECO).

Swipe to scroll horizontally
SpaceX Ax-2 Launch Timeline
TIME (Hr:Min:Sec)EVENTHeader Cell - Column 2
T+00:00:00LiftoffRow 0 - Cell 2
T+00:01:02Falcon 9 at Max QRow 1 - Cell 2
T+00:02:261st stage MECORow 2 - Cell 2
T+00:02:29Stage separationRow 3 - Cell 2
T+00:02:372nd stage main engine startRow 4 - Cell 2
T+00:02:391st stage boost back burn startsRow 5 - Cell 2
T+00:03:28Boost back burn endsRow 6 - Cell 2
T+00:06:251st stage entry burnRow 7 - Cell 2
T+00:07:311st stage landing burnRow 8 - Cell 2
T+00:07:581st stage landingRow 9 - Cell 2
T+00:08:472nd stage engine cutoffRow 10 - Cell 2
T+00:11:58Dragon capsule separationRow 11 - Cell 2
T+00:12:46Dragon nosecone opensRow 12 - Cell 2

What if SpaceX's Ax-2 mission can't launch on time?

SpaceX has an instantaneous window in which to launch the Ax-2 mission, so if it cannot liftoff on May 21 at 5:37 p.m. EDT for any reason, it will have to be delayed at least one day.

There is a backup launch opportunity on Monday, May 22, at 5:14 p.m. EDT (2114 GMT), that SpaceX could use to launch the Ax-2 astronauts, but weather may be a concern. U.S. Space Force officials have said that poor weather moving in early Monday means the launch has just a 20% chance of good conditions for flight. 

If SpaceX is unable to launch the Ax-2 mission for Axiom Space by May 22, the timeline gets a bit more complicated and may lead to a lengthy delay.

NASA currently expects SpaceX to launch an uncrewed Dragon spacecraft on the CRS-28cargo mission on June 3, and plan to give that mission priority if Ax-2 can't lift off this week. Meanwhile, SpaceX rival Boeing is planning to launch its first crewed flight of its Starliner spacecraft in July, a mission that is also a high priority for NASA. 

"If we don't get off on Sunday, Monday we'll get together with NASA and Axiom and SpaceX and kind of look at the whole manifest and see what the next opportunity is for launch opportunity for the Axiom 2 mission," NASA space station manager Joel Montalbano said Saturday.

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Tariq Malik

Tariq is the Editor-in-Chief of Space.com and joined the team in 2001, first as an intern and staff writer, and later as an editor. He covers human spaceflight, exploration and space science, as well as skywatching and entertainment. He became Space.com's Managing Editor in 2009 and Editor-in-Chief in 2019. Before joining Space.com, Tariq was a staff reporter for The Los Angeles Times covering education and city beats in La Habra, Fullerton and Huntington Beach. In October 2022, Tariq received the Harry Kolcum Award for excellence in space reporting from the National Space Club Florida Committee. He is also an Eagle Scout (yes, he has the Space Exploration merit badge) and went to Space Camp four times as a kid and a fifth time as an adult. He has journalism degrees from the University of Southern California and New York University. You can find Tariq at Space.com and as the co-host to the This Week In Space podcast with space historian Rod Pyle on the TWiT network. To see his latest project, you can follow Tariq on Twitter @tariqjmalik.