Air Force GPS satellite

A Falcon 9 SpaceX rocket, with a global positioning satellite for the U.S. Space Force, lifts off from launch complex 40 at the Cape Canaveral Air Force Station in Cape Canaveral, Fla., Tuesday, June 30, 2020. The backup launch opportunity will be on Wednesday at 3:51 p.m., but the weather is expected to be only 40 percent favorable with a higher chance of rain or obscuring clouds.

SpaceX launched another military Global Positioning System satellite in 2018, when the U.S. Air Force said the company couldn't successfully achieve the necessary flight trajectory and also land the first-stage booster, reports SpaceNews. SpaceX says that it was able to work with its customer to ensure that it could complete its mission as planned, while retaining enough reserve fuel for a recovery attempt - something that didn't happen with the first launch. It also marked the first time the company recovered a booster following a National Security Space Launch mission. The spacecraft will deploy approximately 1 hour and 29 minutes after liftoff.

SpaceX's first launch of a Global Positioning System 3 satellite was on December 23, 2018.

Since then SpaceX and the USA military have reached a renewed agreement regarding Global Positioning System mission requirements and the cost of launch - which will allow SpaceX to try to land its first stage after lifting the satellite on Tuesday. It also adds a new L1C civil signal.

This is the third in the most advanced line of Global Positioning System satellites, and joins a constellation of 31 Global Positioning System spacecraft in orbit, according to the Space Force. Each satellite circles the earth twice per day.