# Radiometric Actuators for Spacecraft Attitude Control

## TL;DR

This paper introduces radiometric actuators for spacecraft attitude control, offering a solid-state, high-precision alternative to traditional reaction wheels and magneto-torquers, suitable for small satellites like CubeSats.

## Contribution

The paper presents a novel radiometric actuator design that enables precise, jitter-free attitude control for small spacecraft, with a feasibility analysis included.

## Key findings

- Achieves pointing accuracy of a few arc-seconds or less.
- Eliminates mechanical moving parts, increasing reliability.
- Feasibility analysis supports potential implementation in CubeSats.

## Abstract

CubeSats and small satellites are emerging as low-cost tools to perform astronomy, exoplanet searches and earth observation. These satellites can be dedicated to pointing at targets for weeks or months at a time. This is typically not possible on larger missions where usage is shared. Current satellites use reaction wheels and where possible magneto-torquers to control attitude. However, these actuators can induce jitter due to various sources. In this work, we introduce a new class of actuators that exploit radiometric forces induced by gasses on surface with a thermal gradient. Our work shows that a CubeSat or small spacecraft mounted with radiometric actuators can achieve precise pointing of few arc-seconds or less and avoid the jitter problem. The actuator is entirely solid-state, containing no moving mechanical components. This ensures high-reliability and long-life in space. A preliminary design for these actuators is proposed, followed by feasibility analysis of the actuator performance.

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Source: https://tomesphere.com/paper/1701.07545