Evaluation of a Rear Entry System for an Advanced Spacesuit 2005-01-2976

The success of astronauts in performing Extra-Vehicular Activity (EVA) is highly dependent on the performance of the spacesuit they are wearing. The Space Shuttle Extravehicular Mobility Unit (EMU) is a waist entry suit consisting of a hard upper torso (HUT) and soft fabric mobility joints. The EMU was designed specifically for zero gravity operations. With a new emphasis on planetary exploration, a new EVA spacesuit design is required.

One of the key features of any space suit is the entry method. Historical examples of different entry types include waist entry, rear entry, bi-planar entry, and soft zipper type entry. Suit entry type plays a critical role in defining the overall suit architecture. Some of the critical suit features affected by entry type are suit don/doff capability, suit sizing, suit mass, suit volume, and suit comfort. In general, rear entry designs provide better don/doff capabilities. However, mass and limitations to vertical torso length may be disadvantages of the rear entry design. Entry type is also affected by the vehicle and habitat interfaces such as air locks, hatches, and manned rovers. One concept for planetary exploration is to have an unpressurized vestibule attached to the habitat and have the spacesuit attached to the habitat wall acting as an air lock. This scenario is best supported by a rear entry design minimizing the amount of dust and dirt entering the habitat.

ILC has designed a rear entry prototype upper torso for the I-Suit advanced spacesuit. The design facilitates don/doff while minimizing mass and the negative effects on vertical sizing. This paper discusses research performed at ILC Dover to develop the rear entry design and initial evaluations of the prototype.