A Lightweight EVA Emergency System

The current expendable emergency oxygen generation systems in the Portable Life Support System (PLSS) are lightweight and work well. However, they could generate very high weight penalties when the number and duration of missions (and/or emergencies) are high (as in lunar or Martian explorations). TDA Research, Inc. (TDA) proposes a light-weight emergency unit using a novel regenerable sorbent. In the unit, the sorbent releases oxygen while removing CO2 and H2O. The unit also rejects the heat of absorption to space and maintains the desired degree of cooling. Following the EVA, the sorbent is thermally regenerated with oxygen. A simple oven is the only regeneration equipment required, greatly reducing the weight of the regeneration equipment. In addition, the same unit can also be used for O2 supply and CO2/H2O removal in normal EVAs (i.e., non-emergency cases). The innovation addresses the needs for future long-term microgravity and planetary exploration requirements. Decreased weight reduces the launch costs, easy maintenance increases crew time available for research activities, and an efficient design reduces the logistic train support for replaceable units and spares. In Phase I, TDA will measure the oxygen storage capacity and CO2/H2O loading of the sorbent under simulated PLSS conditions, and carry out 20 full cycles. We will then design the components of the emergency unit and the regeneration system. We will estimate the weight and power requirements.