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.
A hypergolic propellant is a rocket propellant combination used in a rocket engine,whose components spontaneously ignite when they come into contact with each other.
The SM-65 Atlas was the first operational intercontinental ballistic missile (ICBM) developed by the United States and the first member of the Atlas rocket family. It was built for the U.S. Air Force by the Convair Division of General Dynamics at an assembly plant located in Kearny Mesa,San Diego.
Proton is an expendable launch system used for both commercial and Russian government space launches. The first Proton rocket was launched in 1965. Modern versions of the launch system are still in use as of 2023,making it one of the most successful heavy boosters in the history of spaceflight. The components of all Protons are manufactured in the Khrunichev State Research and Production Space Center factory in Moscow and Chemical Automatics Design Bureau in Voronezh,then transported to the Baikonur Cosmodrome,where they are assembled at Site 91 to form the launch vehicle. Following payload integration,the rocket is then brought to the launch pad horizontally by rail,and raised into vertical position for launch.
The Martin Marietta SM-68A/HGM-25A Titan I was the United States' first multistage intercontinental ballistic missile (ICBM),in use from 1959 until 1962. Though the SM-68A was operational for only three years,it spawned numerous follow-on models that were a part of the U.S. arsenal and space launch capability. The Titan I was unique among the Titan models in that it used liquid oxygen and RP-1 as propellants;all subsequent versions used storable propellants instead.
Gemini 1 was the first mission in NASA's Gemini program. An uncrewed test flight of the Gemini spacecraft,its main objectives were to test the structural integrity of the new spacecraft and modified Titan II launch vehicle. It was also the first test of the new tracking and communication systems for the Gemini program and provided training for the ground support crews for the first crewed missions.
Gemini 2 was the second spaceflight of the American human spaceflight program Project Gemini,and was launched and recovered on January 19,1965. Gemini 2,like Gemini 1,was an uncrewed mission intended as a test flight of the Gemini spacecraft. Unlike Gemini 1,which was placed into orbit,Gemini 2 made a suborbital flight,primarily intended to test the spacecraft's heat shield. It was launched on a Titan II GLV rocket. The spacecraft used for the Gemini 2 mission was later refurbished into the Gemini B configuration,and was subsequently launched on another suborbital flight,along with OPS 0855,as a test for the US Air Force Manned Orbital Laboratory. Gemini spacecraft no. 2 was the first craft to make more than one spaceflight since the X-15,and the only one until Space Shuttle Columbia flew its second mission in 1981;it would also be the only space capsule to be reused until Crew Dragon Endeavour was launched a second time in 2021.
A liquid-propellant rocket or liquid rocket uses a rocket engine burning liquid propellants. (Alternate approaches use gaseous or solid propellants.) Liquids are desirable propellants because they have reasonably high density and their combustion products have high specific impulse (Isp). This allows the volume of the propellant tanks to be relatively low.
Pogo oscillation is a self-excited vibration in liquid-propellant rocket engines caused by combustion instability. The unstable combustion results in variations of engine thrust,causing variations of acceleration on the vehicle's flexible structure,which in turn cause variations in propellant pressure and flow rate,closing the self-excitation cycle. The name is a metaphor comparing the longitudinal vibration to the bouncing of a pogo stick. Pogo oscillation places stress on the frame of the vehicle,which in severe cases can be dangerous.
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. Its development was taken over from the Advanced Research Projects Agency (ARPA) 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.
The Titan II was an intercontinental ballistic missile (ICBM) developed by the Glenn L. Martin Company from the earlier Titan I missile. Titan II was originally designed and used as an ICBM,but was later adapted as a medium-lift space launch vehicle to carry payloads to Earth orbit for the United States Air Force (USAF),National Aeronautics and Space Administration (NASA) and National Oceanic and Atmospheric Administration (NOAA). Those payloads included the USAF Defense Meteorological Satellite Program (DMSP),NOAA weather satellites,and NASA's Gemini crewed space capsules. The modified Titan II SLVs were launched from Vandenberg Air Force Base,California,up until 2003.
Titan IIIB was the collective name for a number of derivatives of the Titan II ICBM and Titan III launch vehicle,modified by the addition of an Agena upper stage. It consisted of five separate rockets. The Titan-3B Agena-D was a basic Titan IIIA with an Agena D upper stage. The Titan 23B was a basic Titan II with an Agena upper stage,and the Titan 24B was the same concept,but using the slightly enlarged Titan IIIM rocket as the base. The Titan 33B was a Titan 23B with the Agena enclosed in an enlarged fairing,in order to allow larger payloads to be launched. The final member of the Titan IIIB family was the Titan 34B which was a Titan 24B with the larger fairing used on the Titan 33B.
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.
Project Gemini was the second United States human spaceflight program to fly. Conducted after the first American crewed space program,Project Mercury,while the Apollo program was still in early development,Gemini was conceived in 1961 and concluded in 1966. The Gemini spacecraft carried a two-astronaut crew. Ten Gemini crews and 16 individual astronauts flew low Earth orbit (LEO) missions during 1965 and 1966.
The pressure-fed engine is a class of rocket engine designs. A separate gas supply,usually helium,pressurizes the propellant tanks to force fuel and oxidizer to the combustion chamber. To maintain adequate flow,the tank pressures must exceed the combustion chamber pressure.
The SM-68 Titan was the designation of two intercontinental ballistic missiles developed for the United States Air Force. The Titan I and Titan II missiles were operational between 1962 and 1987 during the Cold War. These missiles,particularly the Titan II,were the basis of the Titan family of space launch vehicles.
OPS 0855,also designated OV4-3,was an American boilerplate Manned Orbiting Laboratory spacecraft launched in 1966. It was flown to demonstrate the launch configuration for future MOL missions. A number of research payloads,designated Manifold,were carried on board,which were intended to operate for 75 days. However,the spacecraft ceased operations after just 30 days. It was built from a decommissioned HGM-25A Titan I first stage oxidizer tank,bolted to a Transtage. It was part of the MOL and Orbiting Vehicle projects.
The LR87 was an American liquid-propellant rocket engine used on the first stages of Titan intercontinental ballistic missiles and launch vehicles. Composed of twin motors with separate combustion chambers and turbopump machinery,it is considered a single unit and was never flown as a single combustion chamber engine or designed for this. The LR87 first flew in 1959.
The 6555th Aerospace Test Group is an inactive United States Air Force unit. It was last assigned to the Eastern Space and Missile Center and stationed at Patrick Air Force Base,Florida. It was inactivated on 1 October 1990.
