Viking rocket - AbsoluteAstronomy.com

The Viking rocket series of sounding rocket

Sounding rocket

A sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, where to sound is to throw a weighted line from a ship into...

s were designed and built by the Glenn L. Martin Company

Glenn L. Martin Company

The Glenn L. Martin Company was an American aircraft and aerospace manufacturing company that was founded by the aviation pioneer Glenn L. Martin. The Martin Company produced many important aircraft for the defense of the United States and its allies, especially during World War II and the Cold War...

(now Lockheed-Martin) under the direction of the U.S. Naval Research Laboratory (NRL). Twelve Viking rockets flew from 1949 to 1955.

Origins

After World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

experimented with captured German V-2 rocket

V-2 rocket

The V-2 rocket , technical name Aggregat-4 , was a ballistic missile that was developed at the beginning of the Second World War in Germany, specifically targeted at London and later Antwerp. The liquid-propellant rocket was the world's first long-range combat-ballistic missile and first known...

s as part of the Hermes project

Hermes project

The Hermes project was an United States Army Ordnance Corps rocket program ....

. Based on these experiments the U.S. decided in 1946 to develop its own large liquid-fueled rocket design, to be called Neptune but changed to Viking. The intent was both to provide an independent U.S. capability in rocketry, to continue the Hermes project after the V-2's were expended, and to provide a vehicle better suited to scientific research. The Navy, in particular, needed a vehicle to study the atmosphere and learn how to predict bad weather which would affect the fleet.

The V-2 would tumble in the rare atmosphere at high altitudes. Having been designed as a weapon, the V-2 carried a large payload, approximately one ton of high explosive. This was more than was considered necessary for the scientific instrument payload of a high-altitude research rocket, but in the case of the V-2, used for research, most of the payload was lead ballast required for stable flight, limiting the potential speed and altitude that could be reached with the smaller payloads typically needed for early scientific investigations.

The Naval Research Laboratory (NRL), partly at the instigation of the American Rocket Society (ARS), chose to build the advanced sounding rocket. Milton Rosen

Milton Rosen

Milton W. Rosen is a former United States Navy engineer and project manager in the US space program between the end of World War II and the early days of the Apollo Program...

, head of the Viking project, credits rocket pioneer Robert Goddard, the ARS, the California Institute of Technology

California Institute of Technology

The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...

and the V-2 for the "profound influence" they had on the design of the rocket.

The Viking was the most advanced, large, liquid-fueled rocket being developed in the U.S. at the time.

Design features

The Viking was roughly half the size, in terms of mass and power, of the V-2

V-2 rocket

. Both were actively-guided rockets, fueled with the same propellants (alcohol and liquid oxygen

Lox

Lox is salmon fillet that has been cured. In its most popular form, it is thinly sliced—less than in thickness—and, typically, served on a bagel, often with cream cheese, onion, tomato, cucumber and capers...

[LOX]), which were fed to a single large engine by turbine-driven pumps. The Reaction Motors XLR10 engine was the largest liquid-fueled rocket engine developed in the United States up to that time, producing 89 kN (20000 lbf) of thrust. As was also the case for the V-2, hydrogen peroxide

Hydrogen peroxide

Hydrogen peroxide is the simplest peroxide and an oxidizer. Hydrogen peroxide is a clear liquid, slightly more viscous than water. In dilute solution, it appears colorless. With its oxidizing properties, hydrogen peroxide is often used as a bleach or cleaning agent...

was converted to steam to drive the turbopump

Turbopump

A turbopump is a gas turbine that comprises basically two main components: a rotodynamic pump and a driving turbine, usually both mounted on the same shaft, or sometimes geared together...

that fed fuel and LOX into the engine.

Viking pioneered important innovations over the V-2. One of the most significant for rocketry was the use of a gimbaled thrust chamber which could be swiveled from side to side on two axes for pitch and yaw control, dispensing with the inefficient and somewhat fragile graphite vanes in the engine exhaust used by the V-2. The gimbals were controlled by gyroscopic inertial reference; this type of guidance system was invented by Robert Goddard, who had partial success with it before World War II intervened. Roll control was by use of the turbopump exhaust to power RCS

Reaction control system

A reaction control system is a subsystem of a spacecraft whose purpose is attitude control and steering by the use of thrusters. An RCS system is capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is also capable of providing torque to allow...

jets on the fins. Compressed gas jets stabilized the vehicle after the main power cutoff. Similar devices are now extensively used in large, steerable rockets and in space vehicles. Another improvement was that initially the alcohol tank, and later the LOX tank also, were built integral with the outer skin, saving weight. The structure was also largely aluminum, as opposed to steel used in the V-2, thus shedding more weight.

Vikings 1 through 7 were slightly longer (about 15 m, 49 ft) than the V-2, but with a straight cylindrical body only 32 in (81 cm) in diameter, making the rocket quite slender. They had fairly large fins similar to those on the V-2. Vikings 8 through 14 were built with an enlarged airframe of improved design. The diameter was increased to 45 in (114 cm), while the length was reduced to 13 m (42 ft), destroying the missile's "pencil shape". The fins were made much smaller and triangular. The added diameter meant more fuel and more weight, but the "mass ratio", of fueled to empty mass, was improved to about 5:1, a record for the time.

Flight history

All except Viking 4 were flown from White Sands

White Sands Missile Range

White Sands Missile Range is a rocket range of almost in parts of five counties in southern New Mexico. The largest military installation in the United States, WSMR includes the and the WSMR Otera Mesa bombing range...

, New Mexico.

The first launch, of Viking 1, on 3 May 1949 came after a very prolonged and trying period of ground firing tests, and attained an altitude of 50 miles (80.5 km). The altitude was limited by a premature engine cut-off, eventually traced to steam leakage from the turbine casing.

Viking 2, flown 6 September 1949, also suffered early engine cut-off for the same reason as Viking 1; it reached only 32 miles (51.5 km). (Subsequent engines had the turbine casing halves welded rather than bolted together, solving the problem.)

Viking 3, 9 February 1950, suffered from instability in a redesigned guidance system, and had to be cut off by ground command when it threatened to fly outside the range. Altitude was again only 50 miles (80.5 km).

Viking 4, on 11 May 1950, launched from the deck of the USS Norton Sound near the Equator, reached a peak altitude of 105 miles (169 km), almost the maximum possible for the payload flown, in a nearly perfect flight. Guidance system was reverted to that of Vikings 1 and 2.

Viking 5, 21 November 1950 reached 108 miles (173.8 km). Engine thrust was about 5% low, or altitude would have been slightly higher.

Viking 6, 11 December 1950, suffered catastrophic failure of the stabilizing fins late in powered flight, with loss of attitude control, and associated very large drag. Altitude was therefore only 40 miles (64.4 km).

Viking 7, 7 August 1951, reached 136 miles (218.9 km) altitude to beat the old V-2 record for a single-stage rocket. This was the highest and last flight of the original airframe design.

Viking 8, 6 June 1952, first rocket of improved airframe design, lost when it broke loose during static testing, and flew to 4 miles (6.4 km) before ground commanded cut-off.

Viking 9, 15 December 1952, reached 136 miles (218.9 km) altitude in the first successful flight of the improved airframe design.

Viking 10. The engine exploded on first launch attempt 30 June 1953. The rocket was rebuilt and was flown successfully 7 May 1954, to 136 miles (218.9 km).

Viking 11 rose to 158 miles (254.3 km) on 24 May 1954, an altitude record for a Western single-stage rocket up to that time. Earth photography and re-entry vehicle test.

Viking 12 was flown 4 February 1955, for re-entry vehicle test, photography, and atmospheric research. It reached 143 miles (230.1 km).

Two additional Viking airframes, similar to Vikings 9 through 12, were flown as test vehicles for Project Vanguard. Both were launched from Cape Canaveral, in 1956 and 1957, and were designated TV0 and TV1.

Achievements

While the underlying motivation for the Viking Project clearly had a national defense component, since it was a US Navy program, it nevertheless established a number of early space exploration landmarks, some technological and some scientific.

Peaceful space travel and space exploration were clearly important objectives that energized many of the higher level instigators even of the German V-2 rocket program, which was funded by the German Army entirely for military purposes. Viking was probably the most ambitious program up to its time which had significant objectives that were essentially scientific, accompanied by a desire to explore and advance rocket technology for more ambitious peaceful space exploration goals, such as artificial earth satellites.

Technological advances pioneered by Viking included the following:

An essentially all-aluminum airframe, with a "mass ratio", of fueled to empty vehicle mass, of about 5:1 for the improved (Viking 8 and later) model, a significant improvement over the V-2, which was largely constructed of steel. The altitude records achieved by Viking, for a single-stage rocket, were mostly the result of its light-weight structure.

Thrust vector control by gimbaling the rocket motor, as opposed to the graphite vanes used by the German V-2 and the U.S. Army Redstone missiles. This method of control has become standard since, both for reliability and efficiency reasons.

Control of the vehicle's orientation, after fuel exhaustion of the main engine, by small auxiliary jets, permitting programmed pointing of scientific instruments, etc.

Extensive radio telemetry for both engineering and scientific data, which greatly reduced the number of test flights needed before useful results were obtained.

Among its scientific achievements, firsts up to their time, were:

The highest measurement of atmospheric density (by Viking 7).

The highest measurement of atmospheric winds (Viking 7).

The first measurements of the atmospheric positive ion composition at high altitude (Viking 10).

The highest exposures of cosmic-ray emulsions (Vikings 9, 10, and 11).

The highest altitude photographs of the Earth (Viking 11).

Through the Viking flights, NRL was first to measure temperature, pressure, and winds in the upper atmosphere and electron density in the ionosphere, and to record the ultraviolet spectra of the Sun.

Viking into Vanguard

The success NRL achieved in this series of experiments encouraged laboratory scientists to believe that, with a more powerful engine and the addition of upper stages, the Viking rocket could be made a vehicle capable of launching an earth satellite. This led to NRL's three-stage Project Vanguard

Project Vanguard

Project Vanguard was a program managed by the United States Naval Research Laboratory , which intended to launch the first artificial satellite into Earth orbit using a Vanguard rocket as the launch vehicle from Cape Canaveral Missile Annex, Florida....

vehicle which launched the second US satellite. Two later rockets in the Viking series, Vanguard TV0

Vanguard rocket

The Vanguard rocket was intended to be the first launch vehicle the United States would use to place a satellite into orbit. Instead, the Sputnik crisis caused by the surprise launch of Sputnik 1 led the U.S., after the failure of Vanguard TV3, to quickly orbit the Explorer 1 satellite using a Juno...

(renamed from Viking 13) and TV1, substantially similar to Vikings 8 through 12, were used as suborbital test vehicles during Project Vanguard

Project Vanguard

, before the first Vanguard vehicle became available for test as TV2, in the fall of 1957.

External links

Adapted from

U.S. Naval Research Laboratory