SpaceX launches Falcon Heavy rocket with 24 satellites

Elon Musk’s Space Exploration Technologies Corp. launched its Falcon Heavy rocket for the U.S. military early Tuesday, a night time liftoff that Musk called the company’s “most difficult launch ever.”

The rocket and payload rumbled aloft at 2:30 a.m local time from NASA’s Kennedy Space Center in Florida after a three-hour delay. Falcon Heavy is carrying 24 satellites for the space agency, Department of Defense research labs and other partners.

SpaceX will try to recover the rocket’s two side boosters -- which flew in April as part of the Arabasat-6A mission -- on Landing Zones 1 and 2 at Cape Canaveral Air Force Station in Florida. The center core will attempt to land on a droneship in the Atlantic Ocean.

The STP-2 mission will place the 24 spacecraft in three different orbits. The payload includes an Air Force Research Laboratory Demonstration and Science Experiments (DSX) satellite; the National Oceanic and Atmospheric Administration-sponsored Constellation Observing System for Meteorology, Ionosphere and Climate-2 (COSMIC-2) and four NASA experiments, according to the SpaceX website. The final deployment will take place more than three and a half hours after the launch.

SpaceX set a company record last year with 21 launches for customers. Last month, the Hawthorne, California-based company sent up the first batch of its own satellites, a key step toward creating a space-based constellation that beams broadband to underserved areas across the globe.

Much of the focus in 2019 has been on the first flight with humans on board. SpaceX and Boeing Co. have contracts with NASA to ferry American astronauts to the International Space Station as part of the agency’s Commercial Crew program.

SpaceX completed the Demo-1 flight of its “Crew Dragon” in March without humans on board. But in late April, the capsule was engulfed in flames and destroyed during a test, a mishap that probably will push back the commercial crew schedule. NASA and SpaceX are reevaluating target test dates.