June 22 at 5:18 am E.T. from SLC-37B at Cape Canaveral Space Force Station

At 5:18 am E.T. United Launch Alliance’s ignited their second to final 235-foot-tall Delta IV Heavy rocket from Cape Canaveral Space Force Station. With 2.1 million pounds of thrust the rocket ignited each of the three boosters in sequence, creating a huge fireball around the vehicle just before lifting off. Known as the heaviest of all rockets because of this unique scene is simply because excess hydrogen leaking from the engine nozzles burns off at ignition.

Unlike their most previous DIVH rocket to launch from Cape Canaveral this mission came with only one delay. Their NROL-44 mission spent almost an entire year on the launch pad with numerous attempts made, including two hot fire aborts. This means the engines had begun ignition and the fireball erupted, but they were quickly shut down and the rocket never moved off the pad. A faulty pneumatic valved cost only a twenty-four-hour delay with the original T-zero at 3:29 am E.T. Wednesday June 21.

Launching on behalf of the NRO (National Reconnaissance Office) this mission was designated the NROL-68 mission. The NRO is the government agency responsible for operating the United States’ fleet of reconnaissance and intelligence gathering satellites. More commonly known as spy sats, these spacecrafts and their true purpose remains classified. These doesn’t mean some clues weren’t available for us to speculate on what the mission entailed.

Having launched from Cape Canaveral suggest a low to mid-inclination orbit, as a Vandenberg, California launch would rather suggest a high inclination orbit. With marine hazard areas posted in the due East direction we can suggest the launch was targeting a geosynchronous or geostationary orbit. As to using the most powerful rocket in ULA’s arsenal, this suggests a significant amount of performance required to complete the mission along with a reasonably heavy payload being taken to the targeted orbit.

NROL-68 marks the fifteenth flight of the Delta IV Heavy, the second to last that will ever fly. It’s also the eleventh time supporting the NRO, with all ten previous missions split evenly between high-inclination and low Earth orbit launches. The final launch of the Delta IV Heavy will take place next year as the company switches to their newest rocket, more than capable of handling the load, the Vulcan.