It is powered by one Russian NPO Energomash RD-180 main engine burning 284,450 kg (627,100 lb) of liquid oxygen and RP-1.

[citation needed] As of 2006[update], the Centaur vehicle had the highest proportion of burnable propellant relative to total mass of any modern hydrogen upper stage and hence can deliver substantial payloads to a high-energy state.

[26] Proposals and design work to human-rate the Atlas V began as early as 2006, with ULA's parent company Lockheed Martin reporting an agreement with Bigelow Aerospace that was intended to lead to commercial private trips to low Earth orbit (LEO).

[27] Human-rating design and simulation work began in earnest in 2010, with the award of US$6.7 million in the first phase of the NASA Commercial Crew Program (CCP) to develop an Emergency Detection System (EDS).

[30] Other than the addition of the Emergency Detection System, no major changes were expected to the Atlas V rocket, but ground infrastructure modifications were planned.

The most likely candidate for the human-rating was the N02 configuration, with no fairing, no solid rocket boosters, and dual RL10 engines on the Centaur upper stage.

[31] In 2011, the human-rated Atlas V was also still under consideration to carry spaceflight participants to the proposed Bigelow Commercial Space Station.

[32] In 2011, Sierra Nevada Corporation (SNC) picked the Atlas V to be the booster for its still-under-development Dream Chaser crewed spaceplane.

[33] The Dream Chaser was intended to launch on an Atlas V, fly a crew to the ISS, and land horizontally following a lifting-body reentry.

[34][35] A three-flight test program was projected to be completed by 2015, certifying the Atlas V/CST-100 combination for human spaceflight operations.

[38][39] In June 2024, on Boe-CFT mission, Atlas V carried humans into space for the first time, launching two NASA astronauts to the ISS.

Customers can also choose to purchase larger payload fairings or additional launch service options.

[51] In 2013, launch costs for commercial satellites to GTO averaged about US$100 million, significantly lower than historic Atlas V pricing.

[56] In 2006, ULA offered an Atlas V Heavy option that would use three Common Core Booster (CCB) stages strapped together to lift a 29,400 kg (64,800 lb) payload to low Earth orbit.

[12] The lifting capability of the proposed launch vehicle was to be roughly equivalent to the Delta IV Heavy,[12] which used RS-68 engines developed and produced domestically by Aerojet Rocketdyne.

A 2006 report, prepared by the RAND Corporation for the Office of the Secretary of Defense, stated that Lockheed Martin had decided not to develop an Atlas V heavy-lift vehicle (HLV).

[58] The report recommended for the U.S. Air Force and the National Reconnaissance Office (NRO) to "determine the necessity of an EELV heavy-lift variant, including development of an Atlas V Heavy", and to "resolve the RD-180 issue, including coproduction, stockpile, or United States development of an RD-180 replacement".

[12] In late 2006, the Atlas V program gained access to the tooling and processes for 5-meter-diameter stages used on Delta IV when Boeing and Lockheed Martin space operations were merged into the United Launch Alliance.

This led to a proposal to combine the 5-meter-diameter Delta IV tankage production processes with dual RD-180 engines, resulting in the Atlas Phase 2.

[60] The Atlas V Common Core Booster was to have been used as the first stage of the joint US-Japanese GX rocket, which was scheduled to make its first flight in 2012.

The first payload, the Hot Bird 6 communications satellite, was launched to geostationary transfer orbit (GTO) on 21 August 2002 by an Atlas V 401.

The Centaur upper stage of the launch vehicle completed its burns over a 56-minute period and placed MRO into an interplanetary transfer orbit towards Mars.

[184] On 6 December 2015, Atlas V lifted its heaviest payload to date into orbit – a 16,517 lb (7,492 kg) Cygnus resupply craft.

[187] The first Vandenberg Air Force Base landing at the Space Shuttle 15,000 ft (4,600 m) runway occurred in December 2010.

The Atlas V launch vehicle performed flawlessly but an anomaly with the spacecraft left it in a wrong orbit.

The cause of the anomaly was traced to a leaky valve, which allowed fuel to leak during the coast between the first and second burns.

[194] 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.

[195] 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 Delta IV.

[196] In September 2014, ULA announced a partnership with Blue Origin to develop the BE-4 LOX/methane engine to replace the RD-180 on a new first-stage booster.

This booster will have the same first-stage tankage diameter as the Delta IV and will be powered by two 2,400 kN (540,000 lbf) thrust BE-4 engines.