Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was developed by Lockheed Martin and has been operated by United Launch Alliance (ULA) since 2006. Primarily used to launch payloads for the United States Department of Defense, NASA, and commercial customers, Atlas V is the longest-serving active rocket in the United States.
Each Atlas V vehicle consists of two main stages. The first stage is powered by a single Russian-made RD-180 engine that burns kerosene and liquid oxygen. The Centaur upper stage uses one or two American-made Aerojet Rocketdyne RL10 engines that burn liquid hydrogen and liquid oxygen. Strap-on solid rocket boosters (SRBs) are used in several configurations.
In 2014, geopolitical and U.S. political considerations because of the Russian annexation of Crimea led to an effort to replace the Russian-supplied NPO Energomash RD-180 engine used on the first-stage booster of the Atlas V. Formal study contracts were issued in June 2014 to a number of U.S. rocket-engine suppliers. The results of those studies led to a decision by ULA to develop the new Vulcan Centaur launch vehicle to replace the existing Atlas V and the Delta IV.
Although ULA intended to complete development of Vulcan by 2019, development took longer than expected and the first Vulcan launch was on 8 January 2024. (NASA/FAA Image)