Height 42 m (138 ft) Engines 5 F-1 engines | Diameter 10 m (33 ft) Burn time 150 s | |
 | ||
Mass 2,280,000 kg
(5,030,000 lb) Thrust 33,400 kN
(7,500,000 lbf) | ||
The S-IC (pronounced "ess one see") was the first stage of the American Saturn V rocket. The S-IC stage was built by the Boeing Company. Like the first stages of most rockets, most of its mass of more than 2,000 tonnes at launch was propellant, in this case RP-1 rocket fuel and liquid oxygen (LOX) oxidizer. It was 42 meters tall and 10 meters in diameter, and provided 33,000 kN of thrust to get the rocket through the first 61 kilometers of ascent. The stage had five F-1 engines in a quincunx arrangement. The center engine was fixed in position, while the four outer engines could be hydraulically gimballed to control the rocket.
Contents
Manufacturing
The Boeing Co. was awarded the contract to manufacture the S-IC on December 15, 1961. By this time the general design of the stage had been decided on by the engineers at the Marshall Space Flight Center (MSFC). The main place of manufacture was the Michoud Assembly Facility, New Orleans. Wind tunnel testing took place in Seattle and the machining of the tools needed to build the stages at Wichita, Kansas.
MSFC built the first three test stages (S-IC-T, the S-IC-S, and the S-IC-F) and the first two flight models (S-IC-1 and -2). They were built using tools produced in Wichita.
It took roughly seven to nine months to build the tanks and 14 months to complete a stage. The first stage built by Boeing was S-IC-D, a test model.
Components
The largest and heaviest single component of the S-IC was the thrust structure, with a mass of 21 metric tons. It was designed to support the thrust of the five engines and redistribute it evenly across the base of the rocket. There were four anchors which held down the rocket as it built thrust. These were among the largest aluminum forgings produced in the U.S. at the time, 4.3 meters long and 816 kilograms in weight. The four stabilising fins withstood a temperature of 1100 °C.
Above the thrust structure was the fuel tank, containing 770,000 liters of RP-1 fuel. The tank itself had a mass of 11 metric tons dry and could release 7300 liters per second. Nitrogen was bubbled through the tank before launch to keep the fuel mixed. During flight the fuel was pressurized using helium, that was stored in tanks in the liquid oxygen tank above.
Between the fuel and liquid oxygen tanks was the intertank.
The liquid oxygen tank held 1,305,000 liters of LOX. It raised special issues for the designer. The lines through which the LOX ran to the engine had to be straight and therefore had to pass through the fuel tank. This meant insulating these lines inside a tunnel to stop fuel freezing to the outside and also meant five extra holes in the top of the fuel tank.
Two solid motor retrorockets were located inside each of the four conical engine fairings. At separation of the S-IC from the flight vehicle, the eight retrorockets fired, blowing off removable sections of the fairings forward of the fins, and backing the S-IC away from the flight vehicle as the engines on the S-II stage were ignited.