työntömoottori

Työntömoottori, known in English as a thruster, is a propulsion device used to provide small amounts of thrust. These devices are crucial for controlling the orientation and position of spacecraft and satellites. Unlike main engines that generate significant thrust for orbital maneuvers or launching, thrusters are designed for fine adjustments.

The principle behind a thruster is Newton's third law of motion: for every action, there is an equal and opposite reaction. By expelling a mass (like gas or liquid) in one direction, the thruster generates a force that pushes the spacecraft in the opposite direction. The amount of thrust is generally much lower than that of a main engine, but it is sufficient for maintaining attitude, desaturating reaction wheels, or performing minor orbital corrections.

Common types of thrusters include cold gas thrusters, which expel a pressurized inert gas, and monopropellant or bipropellant chemical thrusters, which use chemical reactions to produce hot gas for expulsion. Electric thrusters, such as ion thrusters, also exist, offering high efficiency but lower thrust levels. The choice of thruster depends on the specific mission requirements, such as the need for precise control, mission duration, and available power. Their reliable operation is essential for the successful execution of many space missions.