Tuesday’s launch of a covert surveillance payload onto a Delta IV Heavy rocket by the U.S. Space Force and a Boeing-Lockheed joint venture marked the final flight of this reliable launch vehicle type, which has completed over 400 missions since 1960.
The rocket, owned by United Launch Alliance and approximately twenty-three floors high, took off from Cape Canaveral Space Force Station in Florida at approximately 1 p.m. EDT (1700 GMT), exactly twelve days after an earlier attempt at launch was abruptly canceled owing to a technical issue.
The rocket was seen rising from the launch tower through partially cloudy sky on a live ULA webcast, accompanied by a thunderous display of flames and billowing clouds of exhaust and water vapor.
The mission’s goal was to launch a satellite for the National Reconnaissance Office (NRO), a classified U.S. defense intelligence agency, on NROL-70, a classified mission. Hours later, the Space Force field command verified that the payload had been successfully launched into orbit.
It was the sixteenth and last flight of a Delta IV Heavy, as well as the last of the whole Delta family of rockets. The Delta family of rockets began as a modified intermediate-range ballistic missile and expanded to include about two dozen progressively more potent varieties.
The Delta brand has launched 389 times since the Thor-Delta rocket was first used in 1960, marking the beginning of the Space Age. The payloads of these launches have included eight spacecraft to Mars and the first weather and GPS satellites in history.
Thor-Deltas launched the first two communications satellites in history, Echo 1A (passive) and Telstar 1 (active), in 1960 and 1962, respectively. These satellites made it possible to transmit television across the Atlantic.
The twin Mars rovers Spirit and Opportunity were launched in 2003 by Delta II rockets, while the Parker Solar Probe was launched into space in 2018 by a Delta IV rocket, among other space science missions.
According to Tony Bruno, president and chief executive officer of ULA, “the Delta rocket played a pivotal role in the evolution of space flight since the 1960s.”
In favor of its recently developed Vulcan rocket, which made its first flight in January delivering a privately funded lunar lander, ULA, a collaboration between aerospace giants Boeing (BA.N) and Lockheed Martin (LMT.N), opens new tab, is retiring Delta and Atlas rockets.
Although the cargo malfunctioned prior to reaching the moon, the Florida Vulcan launch was successful. Prior to its scheduled retirement, the Atlas V had 17 additional missions scheduled.
When fully fuelled, the 1.6 million-pound (725,748-kg) Delta IV rocket comprises of an upper stage with a single engine that delivers the vehicle’s payload into orbit and a lower stage with three boosters that generate two million pounds of thrust at launch.
The two side boosters of the rocket’s lower stage split and fell away around four minutes into Tuesday’s flight, which saw the rocket reach speeds fifteen times faster than the speed of sound. Two minutes later, the upper stage also separated and ignited.
As the rocket’s top stage ascended above the edge of space, the cargo panels safeguarding the NROL-70 payload during its ascent were removed, approximately 6-1/2 minutes after launch. The authorities requested that live video footage of the flight be stopped at that point, according to ULA.
The NROL-70 mission’s exact nature and goal have been kept under wraps.
Before launch, the government said in a statement that was a little too wordy that the operation would “strengthen the NRO’s ability to provide a wide range of timely intelligence information to national decision makers, warfighters, and intelligence analysts.”
