Development of Gecko-Inspired Adhesive Materials for Space Applications

摘要

The challenges of capturing an uncooperative target in space are numerous, and range from approaching the potentially tumbling target, inspecting it for damage, synchronizing the motion of chaser and target as well as capturing and stabilizing it. Several research groups are currently investigating technologies and algorithms dealing with these challenges, in order to prepare missions that have the goal of an active removal of space debris, or the servicing of non-functional spacecraft on orbit. This work addresses the challenges of docking to such uncooperative targets, investigating the usability of gecko-inspired micropatterned adhesives to be used in a biomimetic docking device. Micropatterned dry adhesives mimic the ability of geckos and several insects to adhere to various materials and surfaces based on van der Waals interactions generated by millions of micro- and nanostructures on their feet. Synthetic adhesives based on that concept have been of high interest in the last decade: the underlying fundamental mechanisms and principles to fabricate these adhesives have been explored thoroughly. However, most of the work has been carried out under ideal conditions in laboratory setups, and preliminary mechanisms work within certain constraints only. In this project, gecko-inspired adhesives are specifically developed and tested for use in the harsh environment of space, including tests according to ECSS standards in terms of outgassing in vacuum, thermal cycling, and long-term duration tests. To demonstrate the functionality of the adhesive pads, a docking device has been developed based on the tested gecko-inspired adhesives that exhibits three-main concepts for robust use in a docking scenario where numerous uncertainties are present: the device is flexible upon docking to be more robust for uncertain docking envelopes, it can be rigidized to be able to transfer higher and more arbitrary loads and torques in post-docking operations, and it can actively share t