Titan was a family of United States expendable rockets used between 1959 and 2005. The Titan I and Titan II were part of the US Air Force's intercontinental ballistic missile (ICBM) fleet until 1987. The space launch vehicle versions contributed the majority of the 368 Titan launches,including all the Project Gemini crewed flights of the mid-1960s. Titan vehicles were also used to lift US military payloads as well as civilian agency reconnaissance satellites and to send interplanetary scientific probes throughout the Solar System.
The Centaur is a family of rocket propelled upper stages that has been in use since 1962. It is currently produced by U.S. launch service provider United Launch Alliance,with one main active version and one version under development. The 3.05 m (10.0 ft) diameter Common Centaur/Centaur III flies as the upper stage of the Atlas V launch vehicle,and the 5.4 m (18 ft) diameter Centaur V has been developed as the upper stage of ULA's new Vulcan rocket. Centaur was the first rocket stage to use liquid hydrogen (LH2) and liquid oxygen (LOX) propellants,a high-energy combination that is ideal for upper stages but has significant handling difficulties.
Delta II was an expendable launch system,originally designed and built by McDonnell Douglas,and sometimes known as the Thorad Delta 1. Delta II was part of the Delta rocket family,derived directly from the Delta 3000,and entered service in 1989. There were two main variants,the Delta 6000 and Delta 7000,with the latter also having "Light" and "Heavy" subvariants. During its career,Delta II flew several notable payloads,including 24 Global Positioning System (GPS) Block II satellites,several dozen NASA payloads,and 60 Iridium communication satellites. The rocket flew its final mission,ICESat-2,on 15 September 2018,earning the launch vehicle a streak of 100 successful missions in a row,with the last failure being GPS IIR-1 in 1997. In the late 1990s,Delta II was developed further into the unsuccessful Delta III,which was in turn developed into the more capable and successful Delta IV,though the latter shares little heritage with the original Thor and Delta rockets.
The Delta rocket family was a versatile range of American rocket-powered expendable launch systems that provided space launch capability in the United States from 1960 to 2024. Japan also launched license-built derivatives from 1975 to 1992. More than 300 Delta rockets were launched with a 95% success rate. The series was phased out in favor of the Vulcan Centaur,with the Delta IV Heavy rocket's last launch occurring on April 9,2024.
Delta IV was a group of five expendable launch systems in the Delta rocket family. It flew 45 missions from 2002 to 2024. Originally designed by Boeing's Defense,Space and Security division for the Evolved Expendable Launch Vehicle (EELV) program,the Delta IV became a United Launch Alliance (ULA) product in 2006. The Delta IV was primarily a launch vehicle for United States Air Force (USAF) military payloads,but was also used to launch a number of United States government non-military payloads and a single commercial satellite.
The Saturn I was a rocket designed as the United States' first medium lift launch vehicle for up to 20,000-pound (9,100 kg) low Earth orbit payloads. The rocket's first stage was built as a cluster of propellant tanks engineered from older rocket tank designs,leading critics to jokingly refer to it as "Cluster's Last Stand". Its development was taken over from the Advanced Research Projects Agency in 1958 by the newly formed civilian NASA. Its design proved sound and flexible. It was successful in initiating the development of liquid hydrogen-fueled rocket propulsion,launching the Pegasus satellites,and flight verification of the Apollo command and service module launch phase aerodynamics. Ten Saturn I rockets were flown before it was replaced by the heavy lift derivative Saturn IB,which used a larger,higher total impulse second stage and an improved guidance and control system. It also led the way to development of the super-heavy lift Saturn V which carried the first men to landings on the Moon in the Apollo program.
National Security Space Launch (NSSL) is a program of the United States Space Force (USSF) intended to assure access to space for United States Department of Defense and other United States government payloads. The program is managed by the Assured Access to Space Directorate (SSC/AA) of the Space Force's Space Systems Command (SSC),in partnership with the National Reconnaissance Office.
The Titan IIIC was an expendable launch system used by the United States Air Force from 1965 until 1982. It was the first Titan booster to feature large solid rocket motors and was planned to be used as a launcher for the Dyna-Soar,though the spaceplane was cancelled before it could fly. The majority of the launcher's payloads were DoD satellites,for military communications and early warning,though one flight (ATS-6) was performed by NASA. The Titan IIIC was launched exclusively from Cape Canaveral while its sibling,the Titan IIID,was launched only from Vandenberg AFB.
Atlas II was a member of the Atlas family of launch vehicles,which evolved from the successful Atlas missile program of the 1950s. The Atlas II was a direct evolution of the Atlas I,featuring longer first stage tanks,higher-performing engines,and the option for strap-on solid rocket boosters. It was designed to launch payloads into low Earth orbit,geosynchronous transfer orbit or geosynchronous orbit. Sixty-three launches of the Atlas II,IIA and IIAS models were carried out between 1991 and 2004;all sixty-three launches were successes,making the Atlas II a highly reliable space launch system. The Atlas line was continued by the Atlas III,used between 2000 and 2005,and the Atlas V which is still in use.
Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin,now being operated by United Launch Alliance (ULA),a joint venture between Lockheed Martin and Boeing. It is used for DoD,NASA,and Commercial payloads. It is America's longest-serving active rocket. After 87 launches,in August 2021 ULA announced that Atlas V would be retired,and all 29 remaining launches had been sold. As of January 2024,17 launches remain. Other future ULA launches will use the new Vulcan Centaur rocket.
United Launch Alliance,LLC,commonly referred to as ULA,is an American aerospace manufacturer,defense contractor and launch service provider that manufactures and operates rockets that launch spacecraft into Earth orbit and on trajectories to other bodies in the Solar System. ULA also designed and builds the Interim Cryogenic Propulsion Stage for the Space Launch System (SLS).
A modular rocket is a kind of multistage rocket which has components that can interchanged for different missions. Several such rockets use similar concepts such as unified modules to minimize expenses on manufacturing,transportation and for optimization of support infrastructure for flight preparations.
The Atlas III was an American orbital launch vehicle,used in the years between 2000 and 2005. It was developed from the highly successful Atlas II rocket and shared many components. It was the first member of the Atlas family since the Atlas A to feature a "normal" staging method,compared to the previous Atlas family members,which were equipped with two jettisonable outboard engines on the first (booster) stage. The Atlas III was developed further to create the Atlas V.
The Atlas I was a US expendable launch system manufactured by General Dynamics in the 1990s to launch a variety of satellites. It was largely a commercial rebrand of the Atlas G,but did feature several electrical and guidance improvements. Atlas I did not feature any major payload capacity improvements over its predecessor but did offer a larger payload fairing option. Eleven launches took place,with three failures.
The Delta IV Heavy was an expendable heavy-lift launch vehicle,the largest type of the Delta IV family. It was the world's third highest-capacity launch vehicle in operation at the time of its retirement in 2024,behind NASA's Space Launch System and SpaceX's Falcon Heavy and closely followed by CASC's Long March 5. It was manufactured by United Launch Alliance (ULA) and was first launched in 2004. ULA retired the Delta IV Heavy in 2024. Future ULA launches will use the new Vulcan Centaur rocket. Delta IV's final flight was in 9 April 2024.
The Delta 1000 series was an American expendable launch system which was used to conduct eight orbital launches between 1972 and 1975. It was a member of the Delta family of rockets. Several variants existed,differentiated by a four digit numerical code. Delta 1000 was developed by McDonnell Douglas company in 1972.
The Delta Cryogenic Second Stage (DCSS) is a family of cryogenic rocket stages used on the Delta III and Delta IV rockets,and on the Space Launch System Block 1. The stage consists of a cylindrical liquid hydrogen (LH2) tank structurally separated from an oblate spheroid liquid oxygen (LOX) tank. The LH2 tank cylinder carries payload launch loads,while the LOX tank and engine are suspended below within the rocket's inter-stage. The stage is powered by a single Aerojet Rocketdyne-Pratt &Whitney RL10B-2 engine,which features an extendable carbon–carbon nozzle to improve specific impulse.
Vulcan Centaur is a two-stage-to-orbit,expendable,heavy-lift launch vehicle by United Launch Alliance (ULA). It is principally designed to meet launch demands for the U.S. government's National Security Space Launch (NSSL) program for use by the United States Space Force and U.S. intelligence agencies for national security satellite launches. It will replace both of ULA's existing heavy-lift launch systems due to their retirement. Vulcan Centaur will also be used for commercial launches,including an order for 38 launches from Kuiper Systems.
During the lifetime of the Space Shuttle,Rockwell International and many other organizations studied various Space Shuttle designs. These involved different ways of increasing cargo and crew capacity,as well as investigating further reusability. A large focus of these designs were related to developing new shuttle boosters and improvements to the central tank,but also looked to expand NASA's ability to launch deep space missions and build modular space stations. Many of these concepts and studies would shape the concepts and programs of the 2000s such as the Constellation,Orbital Space Plane Program,and Artemis program.
