Atlas V

Atlas V: Maximum Flexibility and Reliability

The Atlas V family of Evolved Expendable Launch Vehicles (EELV) represents ULA's commitment to enhanced competitive launch services for the U.S. government. Since their debut in August 2002, Atlas V vehicles have achieved 100 percent mission success in launches from Space Launch Complex-41 at Cape Canaveral Air Force Station, Fla. and Space Launch Complex-3E at Vandenberg Air Force Base, Calif. Built modularly with flight-proven elements, Atlas V has followed a carefully executed program of incremental improvements resulting in 100 percent mission success.  Providing our customers maximum flexibility, capability and reliability has been the foundation of the Atlas program, which has logged more than 600 launches to date.

The Atlas V family, which includes the flight-proven Atlas V 400 and 500 series, are the latest evolutionary versions of the Atlas launch system. Atlas V uses a standard common core booster™ (CCB), up to five strap-on solid rocket boosters (SRB), an upper-stage Centaur in either the Single-Engine Centaur (SEC) or the Dual-Engine Centaur (DEC) configuration, and one of several payload fairings (PLF). A three-digit (XYZ) naming convention is used for the Atlas V 400 and 500 series.

The Atlas V 400 series incorporates the flight proven 4-m diameter 12.0 m (39.3 ft) large payload fairing (LPF), the 12.9 m (42.3 ft) extended payload fairing (EPF), or the 13.8 m (45.3 ft) extended EPF (XEPF).

The Atlas V 500 series incorporates the flight-proven 5-m diameter 20.7 m (68 ft) short, the 23.5 m (77 ft) medium, or the 26.5 m (87 ft) long payload fairing.


Main Engine

Delivering more than 860,000 lbs of thrust at liftoff and an impressive range of continuous throttling capability, the RD-180 main engine is a powerful combination of innovation and performance. Designed and manufactured by NPO Energomash, the liquid oxygen/liquid kerosene, two-thrust-chamber RD-180 engine is a complete propulsion unit equipped with hydraulics for control valve actuation and thrust vector gimbaling, pneumatics for valve actuation and system purging, and a thrust frame to distribute loads.

Nominal Thrust (sea level): 860,300 lbs
Specific Impulse (sea level): 311 seconds
Length: 140 in Weight: 12,081 lbs
Fuel/Oxidizer: Liquid Oxygen/Liquid Kerosene

Solid Rocket Boosters

When missions demand additional thrust at liftoff, Atlas integrates up to three solid rocket boosters (SRB) on the Atlas V 400 series launch vehicle and up to five SRBs on the Atlas V 500 series vehicles. The Atlas SRB, manufactured by Aerojet, uses the world’s largest monolithic filament-wound carbon composite case.

Peak Vacuum Thrust: 380,000 lbf
Specific Impulse: 279.3 seconds
Length: 787 in
Maximum Diameter: 62.2 in
Weight: 102,950 lbs
Nominal Burn Time: 88.3 seconds

Upper Stage

Both the Atlas and the Delta IV upper stages rely on the RL10 propulsion system to power their second stages. Logging an impressive record of nearly 400 successful flights and nearly 700 firings in space, RL10 engines, manufactured by Pratt & Whitney Rocketdyne, harness the power of high-energy liquid hydrogen and boast a precision control system and restart capability to accurately place critical payloads into orbit.

The Atlas V Centaur upper stage is powered by the RL10A and can be configured with either one or two engines.

Nominal Thrust: 23,300 lbs
Specific Impulse: 450.5 seconds
Fuel/Oxidizer: Liquid Hydrogen/Liquid Oxygen
Length: 91.5 in
Diameter: 46 in
Weight: 367 lbs

Payload Fairings

The PLF is designed to provide a controlled environment for spacecraft.

The Atlas V large payload fairing (LPF), extended payload fairing (EPF), and extended EPF (XEPF) have a common 4-m diameter cylindrical section topped by a conical section. Major sections of these payload fairings are the boattail, the cylindrical section, and the nose cone that is topped by a spherical. The EPF was developed to support launches of  larger volume spacecraft by adding a 0.9-m (36-in.) high cylindrical plug to the top of the cylindrical section of the LPF. The XEPF is a modified version of the EPF that incorporates an additional 0.9-m (36-in.) high cylindrical plug to further increase the available payload volume.

The Atlas V 5-m short, medium and long payload fairings were developed along with the increased launch vehicle performance to accommodate evolving spacecraft requirements. The 5-m PLF is a bisector PLF with a composite structure made from sandwich panels with carbon fiber face sheets and a vented aluminum honeycomb core.

All PLFs are configured for off-pad payload encapsulation to enhance payload safety and security, and to minimize on-pad time.


GTO4,750 kg
10,470 lbs
7,700 kg
16,970 lbs
8,900 kg
19,620 lbs
LEO-Reference9,800 kg
21,600 lbs
15,260 kg
33,660 lbs
18,850 kg
41,570 lbs

GTO (Geosynchronous Transfer Orbit)=35,756 km x 185 km at 27.0 deg LEO-Reference (Low Earth Orbit-Reference) =200 km circular at 28.7 deg

Atlas V and Delta IV Technical Summary

Atlas V User's Guide

Aft Bulkhead Carrier Auxiliary Payload User's Guide

Atlas V 400 Series Cutaway Poster

Atlas V 500 Series Cutaway Poster