# A lightweight thermal heat switch for redundant cryocooling on satellites

## TL;DR

This paper presents an optimized, lightweight cryogenic heat switch for satellite cryocooling, utilizing thermoplastic expansion for actuation, with models predicting performance and tests confirming reliability.

## Contribution

The paper introduces a novel, optimized design of a lightweight thermal heat switch for space use, combining predictive modeling and experimental validation.

## Key findings

- Predicts switch contact pressure using a temperature-dependent model.
- Achieves low mass and high stability through optimization.
- Proven reliable through cyclic actuation and shaker tests.

## Abstract

A previously designed cryogenic thermal heat switch for space applications has been optimized for low mass, high structural stability, and reliability. The heat switch makes use of the large linear thermal expansion coefficient (CTE) of the thermoplastic UHMW-PE for actuation. A structure model, which includes the temperature dependent properties of the actuator, is derived to be able to predict the contact pressure between the switch parts. This pressure was used in a thermal model in order to predict the switch performance under different heat loads and operating temperatures. The two models were used to optimize the mass and stability of the switch. Its reliability was proven by cyclic actuation of the switch and by shaker tests.