The launch is an important milestone for Space Force — the sixth branch of the military formed as a Trump administration directive. Until now, the agency has mostly just laid out plans, asked for funding, released a Star Trek-esque logo and inspired a Netflix comedy series starring Steve Carell.

The AEHF-6 satellite will provide “vastly improved global, survivable, protected communications capabilities for strategic command and tactical warfighters operating on ground, sea and air platforms,” Lockheed Martin wrote on its website. It will circle about 22,000 miles above the Earth, and it will serve international partners including Canada, the Netherlands and the UK, Space.com reports.

The rocket and satellite will launch from Florida’s Cape Canaveral Air Force Station, and live stream will begin today at 2:37PM ET.

The SpaceX Crew Dragon, which is slated to be the first spacecraft to carry humans to orbit from American soil since 2011, has arrived at its Cape Canaveral launch site. NASA and SpaceX are already preparing the vehicle for its first flight manned test and will put it through final testing and prelaunch processing over the next months. If all goes well, the first manned flight test will happen as soon as this spring — Elon Musk previously revealed that the launch’s working date is May 7th — and will take off with veteran astronauts Doug Hurley and Bob Behnken onboard.