Elijah Williams
Ending an era in U.S. rocketry, United Launch Alliance fired its 16th and final triple-core Delta 4 Heavy on Tuesday, launching a classified spy satellite in the latest hurrah in a family of rockets that dates back to the dawn of the space age.
The Heavy’s three hydrogen-powered RS-68A first stage engines ignited with a bright orange flame at 12:53 a.m. EDT, gently pushing the 235-foot-tall rocket away from pad 37 at Cape Canaveral Space Force Station in Florida.
United Launch Alliance
The launch occurred 12 days late, largely due to work to replace a pump in a system that supplies nitrogen gas to multiple launch pads from a pipeline that runs through the Kennedy Space Center and Cape Canaveral Space Force Station. There were no problems on Tuesday.
Mounted atop the rocket was a classified satellite provided by the National Reconnaissance Office, the secretive government agency that manages the nation’s fleet of sophisticated radar and optical imaging reconnaissance satellites and electronic listening stations.
In accordance with standard NRO-US Space Force policy for such missions, there are no details on the NROL-70 payload were released. But about six hours after launch, the National Reconnaissance Office declared the launch a success, indicating that the satellite had reached its planned orbit.
“All of our missions are really important, and this one is at the top,” NRO Director Chris Scolese told reporters before the rocket’s initial launch attempt. “But it’s a little more special because it will be the last flight of the Delta 4 Heavy.
“As with all of our missions, they are focused on national security and providing the best information, we believe, in the world to our policymakers, the warfighter and the civilian community.”
Based on the Heavy’s eastern trajectory, safety warnings and other factors, independent analysts concluded that the payload was likely an advanced signals intelligence satellite destined for a geosynchronous orbit 35,000 kilometers above the equator.
Satellites at this altitude appear stationary in the sky as they orbit in sync with the Earth’s rotation, allowing for continuous observations of specific regions.
These signals intelligence satellites are believed to feature giant mesh antennas that unfold in space, acting as “huge… ‘ears’ in the sky, monitoring large areas for radio emissions, mainly military (communications).” , according to Marco Langbroek, an independent analyst based in the Netherlands.
Asked specifically about the nature of the NROL-70 satellite, Scolese told reporters that “there’s really not much I can say other than that it’s a national security payload that will provide an extraordinary capability that is needed by many people and organizations.” clearly to policy makers, the combatant and others, so they can know what is happening.”
In any case, as is standard practice for classified missions, ULA ended its launch coverage with confirmation of the ignition of the second stage engine and separation of the fairing from the payload seven minutes after liftoff. The rest of the ascent was carried out in secrecy.
The final appearance of a Delta rocket 63 years after the inaugural flight of the first variant was an exciting milestone for the managers, engineers and technicians who assembled and launched the latest member of the family.
“Launching the last Delta 4 is bittersweet for me,” said Col. Eric Zarybnisky, director of the NRO Space Launch Office, in a statement. “I was part of the team that launched the first Delta 4 for the NRO. Since then, Delta 4 has launched an incredible capability for this nation into orbit.”
Tory Bruno, president and CEO of United Launch Alliance, also called the flight a “bittersweet” moment as the company continues its transition to next-generation Vulcan rockets, phasing out its more expensive Delta and Atlas families.
“Soon, Vulcan will take up that mantle and we will retire this venerable rocket that has done such important work for our country,” he said after the launch in a pre-recorded video.
“I want to thank everyone who was involved with Delta 4 Heavy. We have many employees who were here for the first Delta 4 launch and who are still here for the last Delta 4 launch to send this great vehicle to its well. -earned his retirement.”
He told reporters previously that closing the Delta line “is obviously the future, moving to the Vulcan, a cheaper, higher-performance rocket.
The single-core Delta 4 and triple-core Heavy were expensive, with some versions of the Heavy reportedly selling for more than $300 million each. Although capable of placing high-priority military payloads into complex, difficult-to-access orbits, the program was not considered sustainable in an era of smaller, more numerous satellites and lower-cost SpaceX boosters.
The Delta family of stages and rockets has its roots in the early space program, first serving in the nation’s fleet of intermediate-range ballistic missiles and evolving through multiple versions used to launch military, NASA and civilian payloads into orbit.
The now-retired Delta 2 debuted in 1990, placing the first Global Positioning System satellites into orbit and sending several planetary probes into deep space, including Messenger to Mercury, several Mars orbiters, the Pathfinder, Spirit and Opportunity Mars rovers, the Spitzer Space Telescope and many more.
The single-core Delta 4 first flew in 2002, with the first Heavy two years later. The single-core version made the program’s last flight in 2019. Tuesday’s launch was the 45th flight of a Delta 4 and the 16th and final Delta 4 Heavy.
“We are very excited to come with Vulcan and carry out these missions, but at the same time, we love this rocket,” Bruno said of the Delta family.
“Delta has existed in one form or another for 60 years,” he added. “He simply has a historic legacy and has done great things for our nation. We are very proud to have been a part of this, and although Vulcan is the future, I am personally sad to see it go.”
