Atlas V

Atlas V is one of the most dependable rockets ever flown. Over more than two decades it carried NASA’s boldest robots to other planets, lofted national-security satellites, and even launched astronauts toward the International Space Station.

Quick facts

• Type: A two-stage, expendable (single-use) launch vehicle, optionally fitted with strap-on solid rocket boosters (small extra motors bolted to the side for added power at liftoff).
• First flight: August 21, 2002, carrying the Hot Bird 6 communications satellite.
• Built by: Lockheed Martin; operated since 2006 by United Launch Alliance (ULA).
• First stage: A single Common Core Booster (3.8 m / 12 ft wide, about 32.5 m / 107 ft long) powered by the Russian RD-180 engine burning kerosene and liquid oxygen, producing about 3.83 MN (~860,200 lbf) of thrust at sea level.
• Upper stage: Centaur, with one or two Aerojet Rocketdyne RL10 engines burning liquid hydrogen and liquid oxygen (~99.2 kN / 22,300 lbf each).
• Lift capacity: roughly 8,210-18,850 kg to low Earth orbit; about 4,750-8,900 kg to geostationary transfer orbit (the path toward high orbits where satellites match Earth’s rotation).
• Track record: A 100% mission success rate and 99% vehicle success rate, with just one partial failure (in 2007) across more than 100 launches. After that 2007 stumble it ran off a streak of dozens of consecutive successes that stretched on for the rest of its career.

What it is and how it works

Atlas V is “modular,” meaning a customer picks parts from a menu to build the rocket they need. Each version has a three-digit name, such as 401 or 551. The first digit is the width of the payload fairing (the protective nose cone over the cargo): “4” means 4.2 m, “5” means 5.4 m, and “N” means no fairing, used for crewed flights. The second digit is the number of strap-on solid boosters (0-3 on the 4-meter class, 0-5 on the 5-meter class). The third digit is the number of RL10 engines on the Centaur upper stage (1 or 2). Think of it like ordering a vehicle and choosing the engine, the cargo space, and how much extra power you want.

At liftoff, the RD-180-powered first stage and any solid boosters provide the muscle to climb out of the thick lower atmosphere. The boosters burn out and drop away, then the first stage shuts down and separates. The cryogenic (super-cold-fueled) Centaur upper stage then lights its RL10 engine or engines. Centaur can shut down and restart several times in space, letting it place payloads into exact orbits or fling them onto escape paths toward other planets.

Why it matters

Atlas V earned trust by combining near-perfect reliability with broad flexibility, making it the chosen ride for the highest-stakes payloads. NASA used it for most of its flagship planetary missions of the 2000s through the 2020s. The U.S. Space Force and intelligence community relied on it for national-security satellites, and Boeing picked it to launch the crewed Starliner spacecraft to the International Space Station. One rocket line could serve commercial communications satellites, navigation payloads, and probes bound for Pluto, Jupiter, Mars, and asteroids. Its record over 100-plus flights set a benchmark for launch reliability.

Its retirement also marks a strategic shift. The high-performance RD-180 was reliable, but relying on a Russian-made engine became a geopolitical and supply-chain concern. ULA bought its final RD-180s ahead of time and is moving to a U.S.-built engine on a new rocket, the Vulcan Centaur.

Notable missions

• New Horizons (2006): Launched by the most powerful version, the Atlas V 551, on a fast path that reached Pluto in 2015.
• Mars exploration: The Mars Reconnaissance Orbiter (2005), the Curiosity rover (2011), MAVEN (2013), and the Perseverance rover (2020) all rode Atlas V.
• Juno (2011): Launched on an Atlas V 551 to study Jupiter’s interior and magnetic environment.
• OSIRIS-REx (2016): NASA’s sample-return mission to asteroid Bennu, flown on an Atlas V 411.
• Boeing Starliner: Flew on a special crew-rated, no-fairing “N22” configuration, including the June 2024 Crew Flight Test carrying two NASA astronauts to the ISS.

The end of an era

ULA stopped selling new Atlas V missions in August 2021 and is retiring the vehicle as its remaining flights are used up. By mid-2026 it had flown about 109 times with only one partial failure and no total losses. The storied Centaur upper stage, whose hydrogen-powered lineage dates to a program first flown in 1962, helped define an era of demanding deep-space missions that Atlas V made routine.