You can watch SpaceX launch advanced GPS satellite tonight. Here's how.

Update for 6:45 pm ET: SpaceX has successfully launched the GPS III SV04 satellite for the U.S. Space Force. Read our full story here. Satellite deployment is expected 1 hour and 29 minutes after liftoff. That's about 8 p.m. EST (0100 GMT). Scroll down for the current webcast.

CAPE CANAVERAL, Fla. — SpaceX is set to launch an upgraded Global Positioning System (GPS) satellite into orbit for the U.S. Space Force today (Nov. 5), and you can watch the action online. 

The flight — the 20th launch this year for SpaceX and its workhorse Falcon 9 rocket — is scheduled to blast off from Space Launch Complex 40 at Cape Canaveral Air Force Station here during a 15-minute window that opens at 6:24 p.m. EST (2324 GMT). Perched atop the rocket is the GPS III-SV04 satellite, which was built by Lockheed Martin. 

You can watch the launch live here and on the homepage, courtesy of SpaceX, beginning about 15 minutes before liftoff. You'll also be able to watch the launch directly from SpaceX here

Related: The U.S. GPS satellite network explained 

Today's launch could have been the second in two days from the Space Coast. On Wednesday evening (Nov. 4), United Launch Alliance (ULA) was scheduled to loft a spy satellite for the U.S. National Reconnaissance Office atop an Atlas V rocket. Unfortunately, issues with the pad’s liquid oxygen fuel lines thwarted that attempt. ULA is currently troubleshooting the issue and could launch the spy satellite as early as Friday (Nov. 6). 

Today's GPS III-SV04 mission has experienced delays as well. The mission nearly got off the ground on Oct. 2, but the Falcon 9's onboard computer detected an issue and the attempt was aborted with just seconds left on the countdown clock. SpaceX worked through the issue, eventually replacing two of the nine Merlin engines in the Falcon 9's first stage.

If all goes as planned today, this will be the fourth launch of an upgraded next-generation GPS III satellite to date. The first and third launched on Falcon 9 rockets, in December 2018 and on June 30 of this year. The second GPS III satellite launched atop the very last ULA Delta IV Medium rocket in August 2019. SpaceX has also secured the next few launches after this one as the military works to upgrade the aging network.

Built by Lockheed Martin in Colorado, these upgraded GPS satellites are some of the most sophisticated spacecraft ever built. They boast anti-jamming capabilities that are eight times more robust than previous iterations and are equipped with more powerful signals for increased accuracy, Lockheed Martin representatives have said.

Today’s launch features the fourth in a series of 10 upgraded GPS III satellites for the military that will join the current constellation of satellites already in orbit. They will help provide positioning, navigation and timing services for more than four billion users worldwide. GPS III-SV04 will replace an aging predecessor that was launched 20 years ago. 

In September, Space Force officials announced that the U.S. military had granted SpaceX permission to launch national security payloads on previously flown rockets. This news followed on the heels of another recent decision to allow SpaceX to recover the first stages of Falcon 9s used on national security missions, something that was previously not allowed. 

SpaceX will launch the next two GPS missions — GPS III-SV05 and GPS III-SV06 — on veteran Falcon 9 first stages next year. The rockets flown on those two missions will also subsequently land back on Earth after their work is done.

However, the star of today’s mission will be a brand-new Falcon 9 first stage, known as B1062 to SpaceX. It’s rare to see a shiny new Falcon perched atop the launch pad these days, as the company has been relying on its fleet of veteran fliers to launch the vast majority of its missions. 

Related: See the evolution of SpaceX's rockets in pictures

Today’s flight will mark the 97th launch of a Falcon 9 rocket and the 64th first stage recovery. SpaceX’s drone ship "Of Course I Still Love You" is positioned out in the Atlantic Ocean, awaiting its planned recovery attempt. Approximately nine minutes after liftoff, the two-stage rocket’s first stage is expected to touch down on the deck of the massive ship. 

GO Ms. Chief, one of SpaceX's net-equipped boats, is heading to the recovery zone to await tonight’s launch. It’s unclear if GO Ms. Chief will attempt to catch the Falcon 9's failing payload fairing — the protective "nose cone" that surrounds a satellite during launch —  or if SpaceX will just scoop the fairing's two halves out of the ocean. (Whether or not a catch is attempted depends on a number of factors, including weather and sea states at the recovery zone.)

SpaceX has been successful in its attempts to reuse more of the Falcon 9, even reusing several fairings on multiple missions. The payload fairing accounts for approximately 10% of the cost of the rocket. Reusing fairings could save as much as $6 million per flight, SpaceX founder and CEO Elon Musk has said.

Launch weather conditions look decent for tonight’s attempt, as weather officials with the Air Force's 45th Space Wing have predicted a 60% chance of favorable conditions at liftoff. According to weather officials, the main concerns are liftoff winds and cumulus clouds.

Follow Amy Thompson on Twitter @astrogingersnap. Follow us on Twitter @Spacedotcom or Facebook.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at:

Amy Thompson
Contributing Writer

Amy Thompson is a Florida-based space and science journalist, who joined as a contributing writer in 2015. She's passionate about all things space and is a huge science and science-fiction geek. Star Wars is her favorite fandom, with that sassy little droid, R2D2 being her favorite. She studied science at the University of Florida, earning a degree in microbiology. Her work has also been published in Newsweek, VICE, Smithsonian, and many more. Now she chases rockets, writing about launches, commercial space, space station science, and everything in between.