- Family: Atlas
- Length: 58.3 m
- Diameter: 3.8 m
- Launch Mass: 433 T
- Low Earth Orbit Capacity: 14067 kg
The Atlas V 421 was manufactured by United Launch Alliance with the first launch on 2007-10-11. Atlas V 421 has 9 successful launches and 0 failed launches with a total of 9 launches. Atlas V is an expendable launch system in the Atlas rocket family. It was formerly operated by Lockheed Martin and is now operated by United Launch Alliance (ULA), a joint venture with Boeing. Each Atlas V rocket uses a Russian-built RD-180 engine burning kerosene and liquid oxygen to power its first stage and an American-built RL10 engine burning liquid hydrogen and liquid oxygen to power its Centaur upper stage. The RD-180 engines are provided by RD Amross, while Aerojet Rocketdyne provides both the RL10 engines and the strap-on boosters used in some configurations. The 421 version uses a 4m wide fairing, 2 solid rocket boosters and one engine on the Centaur stage.
