Update: Tonight’s launch was scrubbed with two seconds remaining in the count and will be rescheduled.
SpaceX is set to launch a GPS-III satellite for the U.S. Space Force using a Falcon 9 rocket, with a target launch time of 9:43 PM EDT (6:43 PM PDT). That opens a 15-minute launch window, and so far weather is looking relatively good, which will hopefully help SpaceX end a recent string of launch scrubs, including one earlier this week for a reset Starlink mission.
The Falcon 9 used for this launch is a rarity these days -- a brand new vehicle, including a booster being used for the first time. The attempt will include a landing of that first stage aboard SpaceX's "Just Read the Instructions" drone landing ship in the Atlantic Ocean.
There's a good reason that SpaceX isn't flying a previously flown booster for this one: The company's contract with the Space Force stipulates that it can only use new, non-refurbished vehicles for National Security Space Launch (NSSL) missions. But they recently announced an updated agreement that will allow SpaceX to use reflown first stages on future flights.
The webcast above will start around 15 minutes prior to the opening of the launch window, so at around 9:28 PM EDT (6:28 PM PDT).