Status of the Advanced Closed Loop System ACLS for Accommodation on the ISS

The Advanced Closed-Loop System ACLS is a regenerative life support system for closed habitats. With regenerative processes the ACLS covers the life support functions of CO2 removal, Oxygen generation and CO2 Reprocessing. ACLS will be accommodated in the Destiny module, which offers all interfaces needed for extended operations.

The form-fit-function FM-like Engineering Model (EM) was completed and served for validation of applied processes and associated control software ahead of its application for flight model operations. The EM is being integrated into the Ground Segment infrastructure in support of flight ops including maintenance procedures' validation.

The ACLS Flight Model (FM) was fully integrated and is in environmental testing to be completed in December 2016. Subsequent safety testing in early 2017 serves for hazard control verification in support of the phase III Safety Review planned for April 2017.

The paper summarizes the development & hardware status in support of the launch of the ACLS FM with HTV7 that is today envisaged for early 2018.

Besides, the paper addresses the potential enhancement of ACLS to an ACLS Mk-II configuration for application in exploration mission module architectures in LEO and beyond.