NASA's Exploration Architecture announced in September 2005, calls for development and flight of a Crew Exploration Vehicle (CEV) no later than 2014 and return to the moon by 2020 with a goal to reach and explore Mars. Intra-Vehicular Activity (IVA) suit systems will need to comfortably protect the crew during launch entry and abort scenarios. Extra-Vehicular Activity (EVA) suit systems will need to provide the capability to perform contingency zero-gravity EVA from the CEV as well as surface EVA to explore the moon and Mars. Studies currently underway to begin definition of the IVA and EVA suits point to a two suit architecture, the first being a launch, re-entry, and contingency EVA system used from CEV, the second and later being a lunar surface mobility suit only. An important consideration, yet to be determined, is the level of commonality between the early CEV and late Lunar suits. One concept is to have maximum commonality beginning with the architecture of the spacesuit upper torso. The upper torso is the foundation of the spacesuit. The upper torso supports the life support system, displays and controls, the opening for entry and closure, the helmet, and the shoulder and waist mobility joints. Upper torso architecture therefore, has a great affect on life support configuration, don/doff capability, mass and volume, suit sizing, and suit performance particularly in terms of visibility, mobility and comfort. Of prime consideration, is the upper torso material. Historically, hard upper torsos (HUTs) have been made of aluminum or composite, and soft upper torsos (SUTs) have been made of dual layer coated and noncoated fabrics. Architecture concepts have included waist entry, rear entry, and zipper closures. Upper Torso architecture is a key driver for the early CEV and late Lunar exploration spacesuit systems definition. This paper provides a review of probable Constellation Program requirements, existing upper torso architectures, and material candidates. Recent developments in the ILC Dover I-Suit fabric upper torso are discussed in relation to meeting program goals. Trade assessments suggest that fabric upper torsos, common to both Constellation Program spacesuits, provide the best advantage to meet the goals of the program.
