The last Delta 4 launcher to fly in a single-core configuration rumbled into space Thursday morning from Cape Canaveral with a GPS navigation satellite, leaving United Launch Alliance with five more Delta 4-Heavy missions on contract through late 2023 before the Delta rocket family retires from service.

Follow the key events of the Falcon 9 rocket’s ascent to orbit with the first 10 next-generation satellites for Iridium’s voice and data relay fleet.

SpaceX plans two Falcon Heavy launches this year for the U.S. Space Force in July and October, and United Launch Alliance has four national security space missions on its 2021 schedule, according to a military spokesperson.