Session
Technical Session VI: Advanced Technologies I
Location
Utah State University, Logan, UT
Abstract
Since the beginning of the space age, many structures with different levels of complexity have been proposed for the deployment of equipment such as solar arrays, antennae, and scientific instruments. By increasing the packaging efficiency, stowing during launch and then deploying in orbit provides an opportunity for the improvement of the capabilities of small satellites payloads while maintaining a contained launch volume. The latter is particularly important when considering the launch of future constellations and, in particular, CubeSats where the volume is significantly constrained by the size of the pod. The focus of this work is the development of a camera/telescope barrel ideally suited for a Cassegrain configured space instrument, hosting the primary mirror at one (satellite side) end and the secondary mirror supported by a cruciform element at the other end (aperture). The barrel is stowed and deployed using a telescopic approach with three coaxial large diameter hollow cylinders making up the segments of the barrel. For an optical telescope, one of the most important challenges is in maintaining a highly accurate distance between the optical elements (in this case, primary and secondary mirrors which are positioned with an accuracy of a few micron). Thermo-mechanical distortions due to on orbit temperature variations and any micro-vibration excitation from sources on the spacecraft can cause significant degradation of the optical performance. To maintain the required shape stability, the main structural parts are made in a thermally invariable material and incorporate features to provide alignment and locking out. The large diameter of the structure, and low coefficient of thermal expansion, give the assembly excellent resilience to thermal and micro-vibration disturbances whilst keeping mass to a minimum. This “tube” arrangement also naturally fulfils the light baffling requirements of the telescope. Another significant challenge is the apparatus to drive the sequential deployment of the cylinders. Systems that use lead screws and gears have been proposed, however they present significant complexities and their mass has a substantial impact on the mass budget of the overall assembly. Here, a novel robust and simple wire-driven system is proposed to operate the deployment. The main advantages being the simplicity, light weight, and robustness with respect to severe vibration environments. This article will describe the development of the device and the testing of the proof of concept/qualification model.
Deployable Optics for CubeSats
Utah State University, Logan, UT
Since the beginning of the space age, many structures with different levels of complexity have been proposed for the deployment of equipment such as solar arrays, antennae, and scientific instruments. By increasing the packaging efficiency, stowing during launch and then deploying in orbit provides an opportunity for the improvement of the capabilities of small satellites payloads while maintaining a contained launch volume. The latter is particularly important when considering the launch of future constellations and, in particular, CubeSats where the volume is significantly constrained by the size of the pod. The focus of this work is the development of a camera/telescope barrel ideally suited for a Cassegrain configured space instrument, hosting the primary mirror at one (satellite side) end and the secondary mirror supported by a cruciform element at the other end (aperture). The barrel is stowed and deployed using a telescopic approach with three coaxial large diameter hollow cylinders making up the segments of the barrel. For an optical telescope, one of the most important challenges is in maintaining a highly accurate distance between the optical elements (in this case, primary and secondary mirrors which are positioned with an accuracy of a few micron). Thermo-mechanical distortions due to on orbit temperature variations and any micro-vibration excitation from sources on the spacecraft can cause significant degradation of the optical performance. To maintain the required shape stability, the main structural parts are made in a thermally invariable material and incorporate features to provide alignment and locking out. The large diameter of the structure, and low coefficient of thermal expansion, give the assembly excellent resilience to thermal and micro-vibration disturbances whilst keeping mass to a minimum. This “tube” arrangement also naturally fulfils the light baffling requirements of the telescope. Another significant challenge is the apparatus to drive the sequential deployment of the cylinders. Systems that use lead screws and gears have been proposed, however they present significant complexities and their mass has a substantial impact on the mass budget of the overall assembly. Here, a novel robust and simple wire-driven system is proposed to operate the deployment. The main advantages being the simplicity, light weight, and robustness with respect to severe vibration environments. This article will describe the development of the device and the testing of the proof of concept/qualification model.
