SpaceX will attempt to launch NASA astronauts Doug Hurley and Bob Behnken to the International Space Station today.

Why it matters: If all goes well, this launch — expected to happen at 4:33 p.m. ET — will mark the first time a private company has successfully launched people to orbit and the first crewed, orbital rocket launch from the U.S. in 9 years.

Follow along below for live coverage…

You can watch live NASA TV coverage of the launch and the lead up to it here:

The latest: Hurley and Behnken have made it to the launch pad and have loaded into the Crew Dragon capsule ahead of launch.

• The two astronauts were transported to the pad by Teslas.

Details: Weather appears to be the limiting factor with this launch at the moment.

• The Air Force is predicting a 50% chance that weather will be favorable at launch time.
• NASA and SpaceX are also closely tracking weather along the Eastern seaboard. If something goes wrong and the mission is forced to abort, the Crew Dragon capsule will be blasted away from the failing rocket to come down to the ocean under parachutes.
• Because of that possibility, mission managers need to be sure that the weather is favorable should an abort occur somewhere along the Falcon 9 rocket’s trajectory.

The big picture: This is SpaceX’s final test flight ahead of being fully certified for operational missions to the space station.

• This mission and those to come are expected to end NASA’s reliance on Russia’s Soyuz spacecraft for launches to the station, bringing back crewed, orbital launches to the U.S. for the first time since the end of the space shuttle program in 2011.

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