Design and testing of a closing and sealing system for a Phobos sample return mission

Abstract

The present paper addresses the development of a closing and sealing system for a container which shall safely bring 100 g of regolith from the surface of Phobos, one of the moons of Mars. Based on a set of requirements defined by the ESA (European Space Agency), a design of the closing and sealing system was made and FEA (Finite Element Analysis) was employed to validate the design. The closing and sealing mechanism along with the Vault (container to be sealed) proved the capability to overcome the Robotic Arm misalignments, to ensure the Vault closing and to maintain the leak tightness (maximum admissible leak rate of 10−4 mbar*l/s Helium) during the trip back to Earth. All these features were validated following an extensive test campaign implying mechanical loads, shocks, thermal vacuum cycling, dust contamination, impact tests and several functional verifications. The mechanism demonstrated the targeted maturity level (TRL 5) and it can be further developed in order to be qualified for a specific mission/application.