RKS: Thermal control system for promising small spacecraft

2022: Development of a thermal control system for promising small spacecraft

Holding Russian space systems"" (RKS, part of) Roscosmos State Corporation reported on July 19, 2022 that specialists had developed a thermal control system for promising small space devices. The innovative coating with movable elements is based on the technology of micromechanical systems. Depending on the solar radiation, the reflective coating satellite changes shape, protecting the spacecraft equipment from overheating without the cost of energy and external control.

In July 2022, small spacecraft are mainly launched into low orbits with a short orbital period around the Earth. In such an orbit, the spacecraft does not have time to overheat on the solar side and overcooled, flying in the shadow of the Earth. However, with the reduction in satellite size or transition to higher orbits, the heat capacity of the spacecraft is no longer enough and the development of specialized temperature control systems is required. To solve the existing problem, the engineers of the RKS holding have developed an adaptive thermal control system that has small weight and size characteristics and does not require power supply.

This PKS design is an external coating of a small spacecraft made of repeating elements - thermomechanical polyimide-silicon actuators, to which light-reflecting plates are attached. Depending on the intensity of the solar radiation, the actuators can rotate the reflective plates. Such a solution ensures thermal control of the spacecraft without requiring additional mechanical structures to equip the hull, and avoids the cost of electricity to the satellite itself.

Imagine indoor blinds, only each flexible "crossbar" or plate is attached to the surface of the satellite with a small leg. When a small spacecraft flies under the rays of the Sun, the legs turn the reflective plate on the body without interference at such an angle that its mirror coating almost completely reflects solar radiation, preventing the supporting structures of the satellite body from warming up and overheating the equipment inside the side. noted Igor Smirnov, head of the sector of micromechanical systems of the RKS.

The creation of a reflective coating with special reflection/absorption coefficients required a wide range of plasma etching experiments at the own site of the PKS Microelectronics Center, where this coating was developed and completely manufactured. Serial production of a variety of microelectromechanical systems of sensitive elements and other high-end (high quality, high-class) electronics on its own production and technological platform allowed RKS to move away from the practice of piece-by-piece, "manual" manufacture of products using the technology of micromechanical systems. They are made only on a plate by the group method without the "human factor." Thus, reliability, speed of manufacture of elements are repeatedly increased and their cost is reduced.