NOTE: Start date changed to 10/01/2008 per M. Perchonok (was 10/01/2007)--5/2009

After working to identify all considerations from hardware design teams and health-related disciplines, AFT continued to act as the primary integrator in developing delivery hardware and selecting an appropriate nutritional beverage.

In light of the findings of the FY2010 glove box assessment of contingency feeding system design concepts, 8 new designs were created during the period, as part of “Generation 2” hardware design for this project. Five of these designs represented modifications to the most successful “Generation 1” hardware to further improve its performance. The remaining 3 designs, although relying on some hardware tested in Generation 1, represent distinct (new) design concepts.

The main proposal in Generation 2 that was expected to improve on earlier hardware was the modification of the feedport nozzle adapter hardware to incorporate a backfill prevention mechanism. Such a backfill prevention mechanism was a resultant recommendation from the glove box testing, as a means to overcome the pressure differential between suit and cabin, but still allow effective dispensing of beverages to a crewmember. The backfill prevention mechanism identified as part of Generation 2 was a one-way check valve that would prevent air from flowing out of the suit and into the feeding system, but still allow liquid to dispense from feeding system into suit. Several watch items were identified relating to the placement of the one-way valve on the nozzle adapter, including a need to confirm that the valve could be cleaned adequately, and that it would function with both low and high viscosity nutritional beverages and nutritional beverage dispersions. Follow on testing is encouraged to verify these watch items for future applications.

Furthermore, if the placement of the one-way check valve on the nozzle adapter is verified, testing of the Apollo Soft Goods Pouch, Toothpaste Key, Toothpaste Turnkey, and Commercial Spouted Pouch designs should also be performed at differential pressure. This would assess the combined effects of backfill prevention and mechanical aids on the effectiveness of dispensing fluid from these designs.

In addition to these proposed modifications to articles evaluated in the glove box assessment, three new designs were proposed to build on the evaluated concepts: a Ratcheting Key, Cable Constricting Restrainer Pouch, and Bag in Bag Concept. The Ratcheting Key design would rely on a rotating key as a mechanical aid.

Due to changes in agency direction, the direct need for a contingency food system is no longer present. This project has, therefore, been concluded prematurely. Still, the work conducted to date on this project is likely to be relevant to NASA needs in the future. In the event that there becomes an interest in pursuing this type of development in the future, researchers have made a diligent effort to summarize project methods, task findings, and specific recommendations for future work.

In light of the conservative design reference scenario identified by integrating disciplines, initial recommendations were provided during the period to EVA hardware design teams on the expected physical properties of a contingency nutrition provision. Top-level assessment and in-house laboratory evaluations of physical properties were conducted on a broad range of commercial nutritional beverages. Upon completion of the in-house evaluation, design input was provided to the EVA T&E hardware team. The input included confirmation that a fluid beverage would be identified or designed to provide at maximum nominal nutrient and kilocalorie levels to suited crew in contingency events. The estimated kinematic and dynamic viscosity ranges for a suited contingency liquid beverage were also provided to the suit and vehicle design teams.

To further aid in designing delivery system hardware, a review of heritage aviation and spaceflight feeding systems was conducted by the Principle Investigator. The review identified several design concepts and open issues that may assist in the design of future contingency feeding capability. A summary of the identified heritage feeding systems and open issues identified in the review was provided to Constellation Program stakeholders. The open issues generally address gaps in an understanding of the food system behavior in (1) the absence of pressure and (2) after exposure to differential pressure, such as that of a spacesuit. To address these issues, the following activities have been performed to date: in-house vacuum testing of packaging materials and glove box assessment of contingency design concepts. Several key findings were confirmed in these efforts.

Integrating disciplines also worked throughout the period to develop detailed schedules for collaboration on this task. A main element of the Space Life Sciences input in the integrated schedule is that of the multi-phased development process for the beverage. By working to the conservative design scenario referenced above, nutritional requirements will be identified by the Nutritional Biochemistry Laboratory and commercial products that meet a majority of the requirements will be scoped by AFT. Upon completion of each market survey assessment, SLSD stakeholders would be informed and have the opportunity to modify their initial recommendations, if necessary. This iterative process is to continue until the most appropriate and technologically feasible beverage requirements have been identified.

The first set of nutritional recommendations for contingency events was received by the PI from SK/Nutritional Biochemistry Laboratory in January 2010. The PI has used these recommendations to conduct commercial product scoping and identify products that may be appropriate for contingency scenarios. During the period, over 300 beverages were considered against the contingency recommendations, including both Ready-to-Drink (RTD) aseptically packaged liquid and Ready-to-Use (RTU) soluble, dry powder formulas. None of the commercial options considered were found to meet the recommendations in full. The results of this scoping will be provided for consideration to SLSD stakeholders, and allow an opportunity for further refinement of the requirements.

The Suited Contingency Food System should provide the nutrient composition specified in HS6062 in per the Constellation Program Human Systems Integration Requirements (HSIR) document No: CxP 70024, section 3.10.3.1.2, In-Suit Nutrition during Unpressurized Vehicle Survival. The nutrition consumption capability would be needed during limited-duration pressurized survival, Intra-Vehicular Activity (IVA) or contingency Extra-Vehicular Activity (EVA), and extended duration pressurized survival for up to 120 hours. When unplanned cabin pressure reduction occurs and during long duration pressurized suited operations, the crew will need to consume nutrition to maintain enough strength to perform vehicle survival tasks. The design specifications placed upon the feeding system of the pressure suit were restrictive. Understanding the feeding system design limitations, requirements, relevant parameters, and guidelines through discussions with the pressurized suit team in the Advanced EVA Technology group will be the first task of this project. The second task will coordinate interface options with nutrition team to obtain the nutritional requirements for crewmember in a pressurized suit during unpressurized vehicle survival operations.

After the establishment of selection criteria for the pressure suited food delivery system, commercially available food items will be identified. All potential food structures will be explored (e.g., liquid foods including true solution and emulsion, semi-solid foods including paste and gel, and solid foods including bar and bite-size foods, etc.)

An evaluation system will be developed with consideration of the selection criteria and be divided into four areas: (1) nutrition evaluation, (2) safety and shelf-life evaluation, (3) systems interface evaluation, and (4) human factors evaluation. The commercially available food items will be screened accordingly. If potentially available food items are selected, further testing will be conducted to assure maximum suitability for a pressure suit feeding system.

If insufficient commercial food items are available, new products will be developed to support astronauts in pressure-suited contingency operations. The developed Suited Contingency Operations Food System can be reapplied to Lunar EVA Operations.