Loki, officially designated 76mm HEAA Rocket T220, was an American unguided anti-aircraft rocket based on the German Taifun. Like the Taifun, Loki never saw service in its original role, but later found widespread use as a sounding rocket. It was so successful in this role that several advanced versions were developed on the basic Loki layout, including the final Super Loki.
As part of their anti-aircraft development program of 1942, the Luftwaffe began developing a number of guided missile projects. However, there was concern that these would not develop in time to be useful in the 1943/44 time frame. To fill the gap, Klaus Scheufelen suggested building a simple unguided rocket that would be fired en-masse directly up into the bomber streams. The result was the Taifun.
Taifun was powered by a hypergolic mixture pressure-fed into the combustion chamber. The pressure was provided by small cordite charges that were fired into the fuel tanks, in the process bursting a pair of thin diaphragms to allow the fuel and oxidizer to flow into the combustion chamber. The Germans were never able to get the engine to work reliably, and the rocket was never deployed operationally.
The US Army had initially studied the Taifun in 1946, and the German engineers now working for the Army were convinced the concept deserved more development. [1] When similar concerns about the development time of their own guided missile projects were raised, the Taifun was reconsidered and a development program started at Bendix in 1948. One major change was to replace the warhead area with a dart-like version, which was separated from the main rocket body at engine burnout to continue on without the drag of the airframe and thereby reach higher altitudes.
Like the Germans before them, Bendix had significant problems with the engine, and eventually decided to develop a solid-fuel engine based on a new elastomeric fuel from the Jet Propulsion Laboratory (JPL), starting in March 1951. The first flight of a solid-fuel Loki occurred on 22 June 1951. [2] The new engine was successful, and the liquid engine was abandoned in February 1952.
An initial meeting on June 25, 1954, at the Redstone Arsenal, of Dr. Wernher von Braun, Frederick C. Durant, Alexander Satin, David Young, Dr. Fred L. Whipple, Dr. S. Fred Singer, and Commander George W. Hoover resulted in an agreement that a Redstone rocket with a Loki cluster as the second stage could launch a satellite into a 200-mile (320 km) orbit without major new developments. [3]
JPL eventually fired 3,544 Lokis at White Sands during the testing program. These tests demonstrated that the launch of one rocket would affect the flight path of the ones behind it, making the dispersion too large to be a useful weapon. [4] Although this problem was studied in depth, it appeared there was no obvious solution. The Army eventually gave up on Loki in September 1955, in favour of the Nike-Ajax missile, which had recently reached operational status, and the MIM-23 Hawk which was expected to be available shortly. [5]
In 1955 the United States Navy took many of the already-completed Lokis and replaced the explosive warhead with a chaff dispenser. These WASP rockets were fired from ships directly upward, and the chaff released at apogee where it was tracked by radar in order to accurately measure the winds aloft. The USAF also used the Loki for this role, assigning it the name XRM-82. The ONR also used the Loki in some of its Rockoon launches, lofting the Loki to high altitudes on a helium balloon before firing.
Many other Lokis were sold into the civilian market, where they became quite popular for meteorological work, referred to as the Loki-Dart. To better serve the needs in this role, a larger-diameter motor with 50% more fuel was developed in 1957, creating the Loki II, the original retroactively becoming Loki I. Other companies developed additional versions, including the Cooper Development/Marquardt Rocksonde 100 with a 100,000 ft maximum altitude and Rocksonde 200 able to reach 200,000 ft.
A variant known as HASP (High Altitude Sounding Projectile) was launched directly from a 5-inch gun barrel. To stabilize the HASP during firing, the dart's small fins were fitted with "bore riders", which guided the rocket along the rifled barrel and thereby also imparted a spin. The bore riders fell free as soon as the dart exited the gun barrel. [6]
In 1963 Space Data Corporation (SDC) formed to provide small sounding rockets to the various defence agencies. They used the meteorological rockets and created an instrument payload for the Loki in place of the chaff dispenser. There were at least three variants of the instrument payload, PWN-10, [7] PWN-11, [8] and PWN-12. [9] The instruments consisted primarily of a thermistor to collect temperature, which was broadcast via a small radio operating in the 1680 MHz Meteorological Band. Altitude was tracked from the ground, by reflecting radar off the probe's "starute", a square mylar parachute and radar reflector, or with the PWN-10 by means of a ranging transponder. The SDC version was slightly heavier than the original Loki in order to improve stability during "cruise", which lowered maximum altitude by about 10,000 ft. Production of the Loki Datasonde started in 1966, and more than 20,000 were built until production ended in 1985.
The Air Force requested a version that would not require radar tracking, and SDC responded by placing a transponder in the payload. This increased payload weight, and required the starute to be enlarged, further increasing launch weight. To reach the required altitudes, SDC developed a much larger booster, which also increased overall weight and further improved stability. The resulting Super Loki first flew in 1968, and since then 9,000 have been delivered.[ citation needed ]
The Air Force Meteorologists and NASA's Observational Scientists desired higher apogees with the ROBINSphere payloads in the early 1970s. In 1972, Space Data completed the development of the 4+1⁄2-inch-diameter (110 mm)Viper IIIA solid propellant rocket motor. This motor followed the design of the Super Loki nearly identically and provided apogees of ~120 km for the ROBINSphere. This higher apogee allowed for measuring the wind and atmospheric vertical profiles through the 110–95 km region that were unobtainable from the Super Loki boosted ROBINSphere. The ROBINSphere is a calibrated weight inflatable 1 meter diameter radar reflecting balloon, weighing in at about 150 grams. The weight is measured within one-half gram. [10]
A design change occurred in 1993 with a change in the elastomeric solid propellant with the more commonly available polymer, HTPB (hydroxyl terminated polybutadiene). This propellant design change occurred both in the Super Loki and the Viper IIIA.[ citation needed ]
Orbital Sciences Corporation bought SDC in 1990. The production of the Super Loki and the Viper IIIA rocket boosted meteorological payloads continued until 2001 when the product line was abandoned.[ citation needed ]
The Jupiter-C was an American research and development vehicle developed from the Jupiter-A. Jupiter-C was used for three uncrewed sub-orbital spaceflights in 1956 and 1957 to test re-entry nosecones that were later to be deployed on the more advanced PGM-19 Jupiter mobile missile. The recovered nosecone was displayed in the Oval Office as part of President Dwight D. Eisenhower's televised speech on November 7, 1957.
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 PGM-11 Redstone was the first large American ballistic missile. A short-range ballistic missile (SRBM), it was in active service with the United States Army in West Germany from June 1958 to June 1964 as part of NATO's Cold War defense of Western Europe. It was the first US missile to carry a live nuclear warhead, in the 1958 Pacific Ocean weapons test, Hardtack Teak.
A sounding rocket or rocketsonde, sometimes called a research rocket or a suborbital rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The rockets are used to launch instruments from 48 to 145 km above the surface of the Earth, the altitude generally between weather balloons and satellites; the maximum altitude for balloons is about 40 km and the minimum for satellites is approximately 121 km. Certain sounding rockets have an apogee between 1,000 and 1,500 km, such as the Black Brant X and XII, which is the maximum apogee of their class. Sounding rockets often use military surplus rocket motors. NASA routinely flies the Terrier Mk 70 boosted Improved Orion, lifting 270–450-kg (600–1,000-pound) payloads into the exoatmospheric region between 97 and 201 km.
Project HARP, short for High Altitude Research Project, was a joint venture of the United States Department of Defense and Canada's Department of National Defence created with the goal of studying ballistics of re-entry vehicles and collecting upper atmospheric data for research. Unlike conventional space launching methods that rely on rockets, HARP instead used very large guns to fire projectiles into the atmosphere at extremely high speeds.
The Saturn family of American rockets was developed by a team of former German rocket engineers and scientists led by Wernher von Braun to launch heavy payloads to Earth orbit and beyond. The Saturn family used liquid hydrogen as fuel in the upper stages. Originally proposed as a military satellite launcher, they were adopted as the launch vehicles for the Apollo Moon program. Three versions were built and flown: the medium-lift Saturn I, the heavy-lift Saturn IB, and the super heavy-lift Saturn V.
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.
Little Joe II was an American rocket used from 1963 to 1966 for five uncrewed tests of the Apollo spacecraft launch escape system (LES), and to verify the performance of the command module parachute recovery system in abort mode. It was named after a similar rocket designed for the same function in Project Mercury. Launched from White Sands Missile Range in New Mexico, it was the smallest of four launch rockets used in the Apollo program.
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.
The Saturn Vehicle Evaluation Committee, better known as the Silverstein Committee, was a US government commission assembled in 1959 to recommend specific directions that NASA could take with the Saturn rocket program. The committee was chaired by Abe Silverstein, a long-time NASA engineer, with the express intent of selecting upper stages for the Saturn after a disagreement broke out between the Air Force and Army over its development. During the meetings the Committee members outlined a number of different potential designs, including the low-risk solution von Braun was developing with existing ICBM airframes, as well as versions using entirely new upper stages developed to take full advantage of the booster stage. The advantages of using new uppers were so great that the committee won over an initially skeptical von Braun, and the future of the Saturn program changed forever.
Viper Dart is an American sounding rocket originally developed in 1972. Space Data Corporation (SDC) developed the vehicle as a mean to increase the apogee of the Super Loki boosted PWN-12A dart. The PWN-12A dart is the non-propulsive second stage that contains a ROBINSphere. The ROBINSphere is a calibrated weight inflatable 1 meter diameter radar reflecting balloon, weighing in at about 150 grams. The weight is measured within one-half gram.
The WAC Corporal was the first sounding rocket developed in the United States and the first vehicle to achieve hypersonic speeds. It was an offshoot of the Corporal program, that was started by a partnership between the United States Army Ordnance Corps and the California Institute of Technology in June 1944 with the ultimate goal of developing a military ballistic missile.
The Judi-Dart is a United States solid fueled sounding rocket .It was manufactured by Rocket power Inc .It belonged to the Loki rocket family. The Judi-Dart was launched 89 times between 1964 and 1970. The Judi-Dart has a length of 2.70 metres, a diameter of 0.08 metres, a maximum flight altitude of 65 kilometres and a launch thrust of 9000 newtons.
Hopi-Dart was an American sounding rocket used by the NASA Marshall Space Flight Center for aeronomy studies in the early 1960s.
The Nike-Cajun was a two-stage sounding rocket built by combining a Nike base stage with a Cajun upper stage. The Nike-Cajun was known as a CAN for Cajun And Nike. The Cajun was developed from the Deacon rocket. It retained the external size, shape and configuration of the Deacon but had 36 percent greater impulse than the Deacon due to improved propellant. It was launched 714 times between 1956 and 1976 and was the most frequently used sounding rocket of the western world. The Nike Cajun had a launch weight of 698 kg (1538 lb), a payload of 23 kg (51 lb), a launch thrust of 246 kN (55,300 lbf) and a maximum altitude of 120 km (394,000 ft). It had a diameter of 42 cm and a length of 7.70 m. The maximum speed of the Nike-Cajun was 6,760 km/h (4,200 mph).
Arcas was the designation of an American sounding rocket, developed by the Atlantic Research Corp., Alexandria, Va.
The RTV-A-2 Hiroc was a product of the United States' first effort to develop an intercontinental ballistic missile (ICBM). The project was named MX-774. The project was canceled in 1947, but leftover funds were used to build and launch three of the planned 10 research vehicles designated RTV-A-2. The design included several innovations; the gimbaled thrust chambers provided guidance control, the internal gas pressure was used to support the airframe and the nose cap was separable. All of these concepts were later used on the Atlas missile and the first two on the Viking rocket. Also developed as part of MX-774 was the Azusa guidance system which was not used on the Hiroc missile but did contribute to the Atlas missile as well as many other early guided missiles launched from Cape Canveral.
Taifun was a German World War II anti-aircraft unguided rocket system. Waves of small, relatively cheap, Taifun flak rockets were to be launched en masse into Allied bomber formations. Although never deployed operationally, the Taifun was further developed in the US as the 76mm HEAA T220 "Loki" Rocket.
Rohini is a series of sounding rockets developed by the Indian Space Research Organisation (ISRO) for meteorological and atmospheric study. These sounding rockets are capable of carrying payloads of 2 to 200 kilograms between altitudes of 100 to 500 kilometres. The ISRO currently uses RH-200, RH-300,Mk-II, RH-560 Mk-II and RH-560 Mk-III rockets, which are launched from the Thumba Equatorial Rocket Launching Station (TERLS) in Thumba and the Satish Dhawan Space Center in Sriharikota.
LEX was a French experimental hybrid-propellant sounding rocket, developed by ONERA. It had the objective of testing a lithergol fueled rocket engine. It was the first rocket in history to use this technology, flying 8 times between 1964 and 1967.
