Group : Space Launch Systems
Status : Retired - No Longer Operational
Origin : United States of America
Contractor : Boeing
Initial Operational Capability (IOC) : 1989
Total Production : 155

The Delta expendable launch vehicle program started in 1959 to meet the requirements of NASA. The Delta I launch vehicle propulsion system took its first stage from the USAF's Thor Intermediate Range Ballistic Missile (IRBM) and the second stage from the US Navy's Vanguard ballistic missile. In 1960 the first Delta I vehicle was capable of delivery a 100-pound payload into the GTO (Geosynchronous Transfer Orbit).

The US Air Force started the Delta II program in 1987 to put into orbit 18 NAVSTAR GPS satellites. The success of the GPS system increased the number of Delta II launch vehicles ordered by the USAF and therefore the success of the Delta II program.

The propulsion system can be configured with two or three stages (typically one RS-27 and two LR-101 for the first stage, one AJ10 motor for the second stage and one Star-48B for the optional third stage) plus 3, 4 or 9 GEM boosters depending on mission needs. Payloads of up to 4,750 lb (2,142 kg) can be put into the GTO and loads of up to 13,280 lb (6,000 kg) into low Earth orbit.

Currently, the Delta II launch vehicle is employed to put into orbit GPS satellites, as well as commercial and civil payloads into low-Earth, polar, GTO and stationary orbits.

Group : Space Launch Systems
Status : Retired - No Longer Operational
Origin : United States of America
Contractor : Boeing
Initial Operational Capability (IOC) : 1998
Total Production : 3

The Delta expendable launch vehicle program started in 1959 to meet the requirements of NASA. The Delta I launch vehicle propulsion system took its first stage from the USAF's Thor Intermediate Range Ballistic Missile (IRBM) and the second stage from the US Navy's Vanguard ballistic missile. In 1960 the first Delta I vehicle was capable of delivery a 100-pound payload into the GTO (Geosynchronous Transfer Orbit).

The Delta III launch vehicle program started in 1995 in response to market needs for space rockets capable of loading larger and heavier commercial satellites. The first Delta III was launched in 1998. Its propulsion system consists of RS-27 motor for the first stage and RL10B-2 for the second stage, as well as up to 9 GEM 46 strap-on boosters.

The Delta III can carry up to 8,400 lb (3,800 kg) of payload to GTO.

Group : Space Launch Systems
Status : Retired - No Longer Operational
Also Known As : EELV, Evolved Expendable Launch Vehicle
Origin : United States of America
Contractor : Boeing
Initial Operational Capability (IOC) : 2002
Total Production : 16
Unitary Cost : USD $350 million

The Delta expendable launch vehicle program started in 1959 to meet the requirements of NASA. The Delta I launch vehicle propulsion system took its first stage from the USAF's Thor Intermediate Range Ballistic Missile (IRBM) and the second stage from the US Navy's Vanguard ballistic missile. In 1960 the first Delta I vehicle was capable of delivery a 100-pound payload into the GTO (Geosynchronous Transfer Orbit). The Delta IV launch vehicles have been designed to launch virtually any medium or heavy-sized commercial or military payload into space. The launch vehicle comprises five different models tailored to meet a wide range of payload and launch profiles requirements (4 models intended for medium and 1 for heavyweight payloads).

The Delta IV along with Lockheed-Martin Atlas V were selected by the US Air Force for the Evolved Expendable Launch Vehicle (EELV) program. The launch vehicle propulsion system consists of the RS-68 motor for the first stage and the RL10B-2 introduced by the Delta III for the second stage. In addition, ATK developed the GEM 60 boosters to be added according to launch needs. The Delta IV can carry a 50,800 lb (23,040 kg) payload to a low earth orbit (LEO), or a 28,950 lb (13,130 kg) payload to GTO. Currently (as of 2004), the US Air Force EELV program comprising the Delta IV and Atlas V launch vehicles is valued at $31.79 billion.

The Boeing Delta IV Heavy variant made its first flight from Cape Canaveral Air Force Station, Florida, on December 22, 2004, placing a demonstration satellite in a lower orbit, which was lower than planned. The first flight lasted 5-hour and 50-minute. Preliminary data indicated that a shorter than expected first-stage burn led to the low orbit. The Delta IV Heavy rocket will undergo modifications to be ready for service deploying most important national security payloads from 2005. The first West Coast Launch of Boeing's Delta IV EELV was conducted at Vandenberg Air Force Base, California, on 27 June 2006. The Delta IV launch system put into orbit a National Reconnaissance Office (NRO) payload.

The final flight of the Delta IV was on April 9, 2024.