PLSS 2.5 Fan Design and Development



Journal Title

Journal ISSN

Volume Title


46th International Conference on Environmental Systems


NASA is building a high-fidelity prototype of an advanced Portable Life Support System (PLSS) as part of the Advanced Exploration Systems Program. This new PLSS, designated as PLSS 2.5, will advance component technologies and systems knowledge to inform a future flight program. The oxygen ventilation loop of its predecessor, PLSS 2.0, is driven by a centrifugal fan developed using specifications from the Constellation Program. PLSS technology and system parameters have matured to the point where the existing fan will not perform adequately for the new prototype. In addition, areas of potential improvement were been identified with the existing fan that could be addressed in a new design. As a result, a new fan was designed and tested for the PLSS 2.5. The PLSS 2.5 fan is a derivative of the one used in PLSS 2.0. It uses the same nonmetallic, canned motor, with a larger volute and impeller to meet the higher pressure drop requirements of the PLSS 2.5 ventilation loop. The larger impeller allows it to operate at rotational speeds that are matched to rolling element bearings, and which create reasonably low impeller tip speeds consistent with prior, oxygen-rated fans. Development of the fan also considered a shrouded impeller design that allows larger clearances for greater oxygen safety, assembly tolerances, particle ingestion, and improved performance. This paper discusses the design, manufacturing and performance testing of the new fans.


United States
United Technologies Aerospace Systems
ICES402: Extravehicular Activity: PLSS Systems
Vienna, Austria
The 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.
Gregory Quinn, Hamilton Sundstrand Space Systems International, Inc, USA
Michael Carra, Hamilton Sundstrand Space Systems International, Inc, USA
David Converse, Hamilton Sundstrand Space Systems International, Inc, USA
Cinda Chullen, NASA Johnson Space Center, USA


Fan, PLSS, Advanced Exploration Systems