The Delta IV Heavy flies for the final time

The final Delta IV Heavy launches from SLC-37B (Credit United Launch Alliance)

The Delta IV Heavy has flown for the final time, successfully launching a top-secret payload to orbit for the National Reconnaissance Office.

The launch took place from Space Launch Complex 37B at Cape Canaveral Space Force Station yesterday afternoon, taking to the skies one last time with its iconic fireball engine start-up at 12:53 pm ET.

Originally meant to launch on March 28th, but was scrubbed due to a failed pump that fed gaseous nitrogen to the launch pad. United Launch Alliance was able to get the pump fixed and scheduled a new date with Space Launch Delta 45.

After sending its thunderous roar across the Space Coast, the Delta IV Heavy passed through Max Q. Shortly after, it jettisoned the 2 common core side boosters and throttled up the center core booster, which continued to fire until just after five and a half minutes into flight.

The center core booster and second stage then separated, and the webcast showed the Delta Cryogenic Second Stage nozzle extending into position before ignition. Just over six and a half minutes into the flight, the tri-panel fairings separated, signaling the end of the public broadcast due to the top-secret payload.

Just over 6 hours after lift-off, United Launch Alliance confirmed a successful mission and the official end of the Delta family of rockets going down in the history books. The Delta IV successfully completed 16 missions over its lifetime, most of which were top-secret national security payloads.

United Launch Alliance is now shifting its focus to its new heavy-lift rocket. This Vulcan rocket will be cheaper to fly and able to maintain the same mission capabilities as the Delta IV Heavy.

It is currently unknown what will become of SLC-37B. It could be either SpaceX taking over and converting it to a Starship pad or it merely being left empty for decades to come, similar to many former launch sites at Cape Canaveral.

The next launch for ULA will be the Crewed Flight Test of Boeing’s Starliner capsule to the International Space Station, which is currently no earlier than May 6th at 10:34 pm ET.

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The Delta IV Heavy flies for the final time
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