United Launch Alliance’s Delta IV rocket has set off for its ultimate mission, marking the end of an iconic era that began more than 60 years ago.
The Delta IV Heavy rocket launched Tuesday morning from Space Launch Complex-37 at Cape Canaveral Space Force Station in Florida. This is the second attempt at bidding farewell to the launch vehicle; the rocket’s original launch date was delayed due to an issue with a liquid pump failure that was discovered shortly before liftoff.
Watch the launch below.
ULA has described its last of the Delta rockets as the “most metal,” as it creates a massive ball of fire seconds before its engines roar to life, engulfing the booster in flames. The dramatic liftoff is designed to burn off excess hydrogen, and it also increases its cool factor by a lot.
For its 16th and final flight, the 235-foot-tall (72-meter), two-stage rocket will carry a classified payload for the National Reconnaissance Office as part of the NROL-70 mission.
The mission was originally scheduled for liftoff on March 28 but the launch was scrubbed due to an “issue with the gaseous nitrogen pipeline which provides pneumatic pressure to the launch vehicle systems,” ULA wrote on X at the time.
ULA’s Delta IV Heavy rocket is the last of the Delta family of medium-to-heavy launch vehicles. The Delta legacy dates back to the Cold War, with the first Delta rocket launched on May 13, 1960, from SLC-17 at Cape Canaveral as part of a program developed by the U.S. government to build a suite of expendable launch vehicles to carry payloads ranging from satellites to deep space missions. The rocket family has had 388 launches spanning across six decades, evolving over time to become bigger and more advanced.
After the Delta chapter comes to a close, ULA’s new Vulcan Centaur rocket is designed to take over. The two-stage-to-orbit, expendable, heavy-lift launch vehicle made its debut in January, sending the private Peregrine lander toward the Moon.