In the early days of the Space exploration, TRW’s System Group was one of five operating units of TRW Inc. Along with its three sister groups – Automotive group, Equipment group, and Electronic group, plus industrial operations – it forms a large corporation that provided many different kinds of products and services to space, defense, aircraft, auto, electronics, and related industrial and commercial markets.
The larger whole of which TRW’s System Group formed a part was a giant international corporation – TRW Inc. Begun as a cap screw manufacturer in Cleveland, Ohio, at the turn of the XXth century, it employed 80, 000 people in the 1950s, maintained facilities in 13 countries, and had an annual sales volume well over $1 billion.
Nearly every engine manufactured in the US – from autos and jets to lawnmowers, - used TRW parts. Most color television receivers carried their electronic components. They manufactured grenade launchers and major subsystems for the MK 46 torpedo. Their cams, gears and bearings were used in a large proportion of automobiles and aircraft in the US and Western Europe.
TRW began in the early days of the ballistic missile crisis, providing systems engineering and technical direction on the Atlas, Thor, Titan, and Minuteman missiles. In addition to their headquarters facilities in Redondo Beach, the group had at that time major operations located at Houston, Washington D.C., and Cape Canaveral. They numbered some 16, 000 scientists, engineers, and support personnel, who applied advanced technology to some of the critical military, scientific, and socio-economic problems of our times.
Since the early days of its participation in the ballistic missile program, TRW designed and manufactured a variety of rocket engines for powering and controlling upper stage vehicles and spacecraft. One of their assignments included the design and manufacture of the Lunar Module Descent Engine, which safely landed Apollo astronauts on the surface of the Moon.
The TRW LM Descent Engine was assigned an extremely critical role: to launch an LM containing the two astronauts into a lunar transfer orbit (path which brought them directly to the lunar surface), then slowed their rate of descent from 3500 mph to zero at 200 feet above the lunar surface, and finally lowered them safely to a soft landing. To perform these tasks, it must be throttleable (capable of varying rates of thrust) – and, of course, it had to be very dependable. The LMDE was a pressure-fed, liquid be-propellant, gimballing (capable of swivelling so as to change the direction of thrust) rocket engine. It produced a maximum thrust of 10,000 pounds and was throttleable down to approximately 1050 pounds. The propellants, nitrogen tetroxide (N2O4) and a 50-50 blend of hydrazine and unsymmetrical dimethyl hydrazine, are hypergolic, - that is, they ignite upon contact with one another. Total weight of the engine without propellants was about 290 pounds.
Each of the two Mariner’ 60 spacecraft incorporated a TRW-built propulsion subsystem. The Mariner 6 engine was fired in February of 1969 at 750,000 miles from Earth, the Mariner 7 in April at 2 ½ million miles, precisely adjusting the trajectories of both spacecraft for accurate flights past Mars in July and August of 1969. The weight of Mariner 69 engine was of 45 pounds including propellant. It stood slightly over 3 feet high and was capable of two starts and fired at 50 pounds of constant thrust.
The TRW identity as System group was perhaps best indicated by a 16 x 31-feet mural called “The Quadrisciences” which was displayed in the administration building at Space Park. The mural symbolically depicted four areas of man’s quest for knowledge: the earth, the sea, near space, and deep space. The TRW’s goal at System group was to acquire and apply scientific knowledge in those four environments.
From space craft design and manufacturing to anti-submarine warfare, from building mid-course correction engines for the Mariner Mars spacecraft to evaluating methods of high-speed ground transportation, from designing electronic warfare devices to developing plans for solving such pressing social problems as water and air pollution, overcrowded medical facilities, and ineffective community services - in short, in all for environments of Quadrisciences – the TRW expanded the frontiers of basic research in order to build a better world.
One example of electrical propulsion research at TRW: They developed an engine, a colloid microthruster, under contract to the Air Force. During the first 500-hour firing it produced 32 micro-pounds of thrust and 1SP of 1200 seconds. Engines like this, which have ISPs in the range of 800-1500 seconds and operational life expectancies of thousands of hours, are useful for such tasks as stationkeeping (keeping a spacecraft in the correct orbit), and attitude control (keeping a spacecraft pointed in the right direction). That engine weighs only 8-3/4 pounds together with a 5-watt electrical power unit.