The countdown has started on the long goodbye to Atlas rockets

When an Atlas 5 rocket launched July 30 for the U.S. Space Force, it carried a special distinction: it was the last national security mission for the venerable workhorse rocket.

Sure, the Atlas 5 still has about 15 more launches for commercial customers and NASA in the next year and a half, but the July launch marked the beginning of what’s expected to be a long goodbye to the family of rockets that dates back decades and claims a heritage of more than 600 launches.

Soon, United Launch Alliance, the joint venture from Boeing and Lockheed Martin, plans to replace the Atlas 5 with a new rocket known as Vulcan.

“There’s a lot of work to do still,” Marty Malinowski, ULA’s chief engineer of the Atlas fleet, said of the remaining manifest.

But while a formal farewell is still at least a year away, the countdown has started and the reflections on missions past have already begun.

Tory Bruno, the chief executive of ULA who has been at the helm since 2014, said in a phone interview that following the July 30 launch he heard from usually restrained military officials who noted the occasion of their last day with an Atlas 5. 

“’What a rocket and what a great service it’s done for the nation. Sorry to see it go and looking forward to Vulcan.’ Almost every note has those words,” Bruno said.

The Atlas family history began in the 1950s, later launched the first astronauts from Earth and evolved into multiple iterations. Atlas 3, which introduced the Russian-built RD-180 engine, first launched in 2000 and the Atlas 5 followed with its first launch using the same engine two years later. Bruno pointed to the Centaur 3 upper-stage engine as one reason for the rocket’s recent track record. 

“What an amazing Ferrari of an upper stage,” he said. 

Malinowski pointed to the modular capability of the rocket to order on demand the configuration a customer needed so the capability best matches a payload. (Bruno has jokingly given each a nickname.)

For more than a generation — and often as the only option at its class — the Atlas launched satellites for the Air Force, later the Space Force and the National Reconnaissance Office, the intelligence community’s space arm. Those missions included GPS satellites, six satellites for the Space Based Infrared System, the Defense Department’s missile warning satellites, and six Advanced Extremely High Frequency Satellites, which allow for highly protected satellite communications. The latter have been considered the crown jewels of the Pentagon’s unclassified space architecture for years.

It also launched the Air Force’s secretive X-37B spaceplane several times. None of these were Bruno’s favorite national security mission though. What was it? “I can’t tell you,” he said with a laugh.

There are also a series of high-profile missions for NASA in recent years.

Among the highlights:

• New Horizons, an interplanetary space probe that launched from Cape Canaveral in 2006 aboard an Atlas 5, later flew by and studied Pluto and objects in the Kuiper belt in the outer solar system.
• OSIRIS-REx, a NASA asteroid study and return mission, which launched in September 2016 and returned samples to earth in September 2023.
• The Mars Reconnaissance Orbiter, which was designed to search for the existence of water on Mars and launched in 2005.

Aaron Ridley, a professor at the University of Michigan who teaches courses on rocketry, said Atlas will likely be remembered for its workman-like output. ULA touted a 100% track record of mission success but was criticized as too expensive — missions could cost hundreds of millions of dollars — by competitors.

“It’s like a semi-truck, right?,” he said. “It's the reproducibility and the reliability. That really is the important thing.”

A date for the final Atlas 5 launch has not yet been set.

Mike Gruss is a freelance journalist based in northern Virginia. Previously, he was editor-in-chief of Sightline Media Group, where he led publications including Defense News and Military Times, and has worked as the military reporter at SpaceNews.