Pressurization is one of the key elements that make travel beyond Earth’s atmosphere possible. Almost everything that goes into space is pressurized in some way, from the engine to the cabin. Extensive testing on the ground as well as precise measurement and control of pressure during a flight are what make missions to space successful.
A rocket engine can have several different configurations but the thrust produced is made up of a few basic ingredients following the recipe of Newton’s third law. The ingredients include fuel of some sort and a system to accelerate this fuel to create thrust. Some engines are pressure fed, which means that they use a pressure gradient to create propulsion. Other rocket engines are more complex, using a system of turbines, pumps and various fuel and gas reservoirs in order to maintain the perfect thrust to escape Earth’s atmosphere. No matter the type of engine, every step of the process involves pressure checkpoints, where pressure sensors take readings to make sure the rocket engine is running properly.
Within a rocket engine, pressure transducers can usually be found with the oxidizer inlet, combustion chamber, fuel inlet, thrust control and turbo pumps. Liquid fuel, oxygen and other gases are employed to give the engine the perfect cocktail to lift off, leave Earth’s atmosphere and arrive at its intended coordinates in space. These transducers ensure the different fuel elements are being mixed properly and delivered into the combustion chamber at an acceptable rate to produce the right amount of thrust. To do this, transducers must withstand extremely high pressure, hot temperatures, rugged environments and have a dynamic characterization.
While each individual transducer and controller is tested extensively before it leaves the manufacturer's factory, it’s also tested on the production line of the engine or other sub-components. The testing phase is imperative to discovering any potential problems or dangers within a rocket before it lifts off. Automated pressure controllers such as Mensor’s CPC6050 Modular Pressure Controller and CPC8000 High End Pressure Controller, as well as precision pressure transducers like the CPT9000, are commonly used on the production line to quickly verify pressure sensors are working properly before they are installed on a rocket.
Space missions have been delayed or canceled due to faulty pressure transducers. Crashes, explosions and fuel fires are possible when engines malfunction. Small reading errors can quickly become dangerous situations if not corrected. That’s why calibration is vital to the aerospace industry. Challenges they face in calibration are generating high pressure, their harsh environments, as well as the wide range they must be able to measure and control. To test sensors for this application, a high accuracy reference device that can measure and control high pressures is required. Pressure controllers, such as the CPC7000 pneumatic high-pressure controller, are ideally suited for the harsh conditions, pneumatic contamination-free operation and precise measurement involved in calibrating sensors used on rockets. Pressure transducers like the CPT9000 that can provide high-accuracy measurements even in harsh conditions are also suited as a measurement reference standard.
Regular testing and calibration ensure there are no mission delays and that engines are performing up to the highest standard when the launch countdown begins. High accuracy and reliability are key to efficient and safe missions to space. In rocketry, like anything else, practice makes perfect - test facilities and calibration labs are key to the process of successfully producing a rocket that can safely travel beyond earth’s atmosphere.