Thursday morning’s launch of Atlas V and Amazon Leo LA-08 will be the last time the venerable rocket flies a mission for anything other than Starliner.

There are, of course, six remaining Atlas V missions to launch the Boeing Starliner capsule to the International Space Station, but there is also great uncertainty about when, and some say if, those missions will launch. Starliner-1 is planned as an uncrewed test mission, but its launch date has not been set while Boeing and NASA assess the readiness of the troubled space ferry capsule. That in mind, it is fair to say that Wednesday might mark the last Atlas V seen at the Cape for quite a while.

Beginnings

Convair began studying the design in the late 1940s under the US Air Force. The program took shape in the 1950s as the nation’s first operational intercontinental ballistic missile. Engineers chose a radical approach to save weight. The Atlas used a thin stainless-steel balloon tank that held its shape by internal pressure rather than a rigid internal frame. An empty Atlas could collapse under its own weight if the tanks lost pressure.

The missile also used an unusual stage and a half design. All three engines lit at liftoff and two outer booster engines dropped away during flight while the center sustainer engine kept firing. This avoided the risk of igniting an engine at high altitude, which was a real concern with 1950s technology.

Mercury and the road to orbit

Atlas earned its place in history on February 20 1962 when an Atlas LV-3B launched John Glenn into orbit aboard Friendship 7. He became the first American to circle the Earth. The rocket carried three more Mercury orbital flights and proved that the missile could be trusted with human lives. Four more Mercury missions would launch aboard Atlas, until the program ended.

Through the 1960s Atlas also launched a long list of robotic missions. It boosted Mariner probes toward Venus and Mars and lofted Ranger and Surveyor spacecraft toward the Moon ahead of Apollo. Paired with the Centaur upper stage, the first American stage to use liquid hydrogen, Atlas became a true deep space launcher and a reliable workhorse for NASA and the US Air Force.

Reinvention after the Cold War

The missile role faded but the launch vehicle kept evolving. General Dynamics, then Lockheed Martin, produced the Atlas II and Atlas III through the 1990s. These versions retired the old balloon-booster heritage step by step and improved reliability for both commercial and government customers.

The biggest break came with the Atlas V, which debuted in 2002 under what became United Launch Alliance. It dropped the stainless steel balloon tanks entirely in favor of a rigid structure. In a twist of history, the Atlas V flies on the Russian built RD-180 engine, a powerful and efficient design that gave the rocket its muscle for two decades.

The decision to use Russian engines was not a casual one — the Soviet Union had disintegrated, and there were real concerns in the West that the engineers and technicians who were employed by NPO Energomash would end up on North Korean, Iranian or another adversary’s payroll. In buying the RD-180, the US government hoped to keep those employees on the payroll and out of enemy hands.

In return, ULA got a dual-combustion chamber and dual-nozzle engine high performance engine, that allowed for gimbaling and continuous thrust throttling as it powered the new rocket towards orbit. The combination was perfect for the US military’s Evolved Expendable Launch Vehicle (EELV) program. First used on the Atlas III, the RD-180 was selected for the next iteration of the Atlas design, the Atlas V, where it has been a reliable and successful powerplant for one of America’s leading launch service providers.

Steady Performer

Atlas V has been a steady performer for ULA. It debuted on August 21, 2002, launching the Hotbird 6 satellite for Eutelsat. Over its 109 launch history, Atlas V has launched the Curiosity and Perseverance rovers toward Mars, the New Horizons probe to Pluto, the Juno mission to Jupiter, the Starliner missions and 58 national security missions.

The line is now winding down. ULA has shifted to the new Vulcan rocket and is working through the final Atlas V launches on its manifest. When the last one flies it will close a chapter that runs straight back to the dawn of the Space Age.

Author: Charles Boyer

NASA kid from Cocoa Beach, FL, born of Project Apollo parents and family. I’m a writer and photographer sharing the story of spaceflight from the Eastern Range here in Florida.