Celebrating 50 years since humankind’s lunar landing and our significant role in that achievement
On July 16, 1969, Apollo 11 launched and on July 20 was the first landing of humans on the lunar surface with Parker Aerospace making the journey possible - from blast off to first step, and the return. Parker equipment provided vital functions on all three booster stages (first, second, third stage), the Command Service Module (CSM), the Lunar Module (LM), and even the astronauts’ suits.
From the development of the program, the early tests of Apollo 7 and Apollo 8, the landmark Apollo 11 landing, and through the final Apollo 17 Mission, Parker played an important role in the historic events. Parker Aerospace is proud of the important role played by our engineers and equipment.
During prelaunch operations and during the mission, Parker made sure the crew and spacecraft were safe. The ground support shutoff valves located in the launch pad complex directed liquid oxygen and fuel to the various Apollo systems. Eight six-inch ball valves were used during the fuel and oxygen fill operations of the first stage. The valves were also used to drain the vehicle in the event of an extended hold condition on the mission. Ten eight-inch pre-valves were used during the fuel and oxygen fill operations for the vehicle second stage
Fluid systems throughout the Apollo vehicle relied on specially designed Parker seals and fittings to prevent leaks that could cause serious mission delay. Critical sealing applications, such as the vehicle observation windows, relied on Parker seals to safeguard the astronauts. High-precision tube fittings, designed to meet exacting NASA specifications, were used throughout the vehicle to ensure leakproof, dependable connections on essential systems.
Beginning with ignition through the entire flight of the first stage, the four-inch ball valves circulated and maintained liquid oxygen (LOX) for the engines while the gaseous oxygen (GOX) flow control valve maintained a constant tank pressure during the first-stage operation.
After burnout and separation of the first stage, the accumulator reservoir manifold assembly (ARMA) provided the hydraulic energy for positioning the second-stage outer engines to assure proper mission trajectory. One hydrogen control valve and one oxygen control valve regulated the second-stage hydrogen and oxygen flow to the propellant tanks to maintain a constant propellant pressure during operation. Propellant shutoff valves were installed in each of the second-stage engine inlet lines. These valves would close in the event of an emergency, to shut off fuel to the malfunctioning engine.
When the vehicle reached an altitude of approximately 108 miles above the Earth, the second-stage separated, and the third-stage ignited. At the time of ignition, the LOX check valves served a vital function by preventing liquid oxygen and liquid hydrogen backflow into their respective supply tanks. Further protection of the all-important third stage was assured with the use of highly reliable hydraulic check valves throughout the hydraulic system.
During the entire mission, from countdown to separation of the service module prior to re-entry, the Apollo program utilized the Parker fuel cell reactant supply modules and oxygen and hydrogen modules. The fuel cell reactant supply modules controlled the flow of hydrogen and oxygen to the fuel cells, which furnished complete mission electrical power. The oxygen and hydrogen modules controlled the temperature and pressure in the oxygen and hydrogen storage tanks. Oxygen used for cabin pressurization was also controlled by this module.
The oxygen control assembly performed vital pressure control through the entire mission until lift-off from the lunar surface.
The assembly also controlled the oxygen used to pressurize the LM cabin and the astronauts’ suits. In addition, the oxygen control assembly was used to fill the astronauts’ backpacks for their lunar exploration. This assembly received high-pressure oxygen from the LM supply tanks and regulated the pressure to a usable level.
When the moment arrived for the astronauts to leave the lunar parking orbit and proceed to the surface of the moon, a command was given for Lunar Module (LM) separation from the Command Service Module (CSM). From here, the reaction control system (RCS) maneuvered using reaction control valves that were used to turn the LM to the descent attitude and control steering and attitude during descent to the surface of the moon. These valves were also critical to astronaut safety during ascent from the lunar surface and during hover, rendezvous, and docking maneuvers.
The descent engine was used to slow the LM from the lunar parking orbit and guide it to the lunar surface. The engine propellant tanks were pressurized by a Parker pressurization system. This system was comprised of a helium pressure-reducing valve, quad-check valve, burst disc, and relief valve. The helium pressure-reducing valve regulated the LM high-pressure helium, which forced the fuel and oxidizer into the engine.
The quad-check valve, used in both descent and ascent operations, prevented any backflow that might allow mixing of propellants. The burst disc acted as a seal, preventing propellant liquid or vapors from reaching the relief valve and, causing a corrosive reaction, worked in conjunction with the relief valve to prevent over pressurization of the system.
When the LM was unpressurized or the space suit umbilical cord was used, a suit loop pressure switch was incorporated in the system to assure maximum astronaut safety in the event of a torn suit.
Apollo 11’s touchdown on the moon was famously televised on July 20 and the post-lunar landing conversation between astronauts, “Cycle that Parker Valve,” was heard across the world. These valves were used to isolate the propellant feed systems, which were cycled open and closed immediately after landing. For years after, Parker Hannifin President and CEO Pat Parker would jokingly thank NASA and the astronauts for helping with Parker’s first global television advertisement from the moon.
Parker’s early work on the frontiers of space technology, made possible by our expert engineers and technicians, played a key role in the design, production, and flight of Apollo spacecraft. Parker equipment directly supported the success of Apollo missions as well as its astronaut’s safety.
The people of Parker Hannifin felt enormous pride during the years of the Apollo’s design, production, and flight. Today, remembering the part Parker played in this incredible achievement, we are still proud and humbled to be part of history.
This post was contributed by Brian King, eBusiness manager for Parker Aerospace.