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Two versions of a prototype Free Flight cockpit situational display (Basic and Enhanced) were examined in a simulation at the NASA Ames Research Center. Both displays presented a display of traffic out to a range of 120 NM, and an alert when the automation detected a substantial danger of losing separation with another aircraft. The task for the crews was to detect and resolve threats to separation posed by intruder aircraft. An Enhanced version of the display was also examined. It incorporated two additional conflict alerting levels and tools to aid in trajectory prediction and path planning. Ten crews from a major airline participated in the study. Performance analyses and pilot debriefings showed that the Enhanced display was preferred, and that minimal separation between the intruder and the ownship was larger with the Enhanced display. In addition, the additional information on the Enhanced display did not lead crews to engage in more maneuvering.

We present a device for collecting and storing feces in microgravity that is user-friendly yet suitable for spacecraft in which cabin volume and mass are constrained. On Apollo missions, the commode function was served using disposable plastic bags, which proved time-consuming and caused odor problems. On Skylab, the space shuttle, and the International Space Station, toilets have used airflow beneath a seat to control odors and collect feces. We propose to incorporate airflow into a system of self-compacting, self-drying collection and stowage bags, providing the benefits of previous commodes while minimizing mass and volume. Each collection bag consists of an inner layer of hydrophobic membrane that is permeable to air but not liquid or solid waste, an outer layer of impermeable plastic, and a collapsible spacer separating the inner and outer layers. Filled bags are connected to space vacuum, compacting and drying their contents.

We consider the heat transfer characteristics of an ideal concentric disk used in the Wiped-Film Rotating-Disk (WFRD) evaporator for the Vapor Phase Catalytic Ammonia Removal (VPCAR) water recovery system. A mathematical model is derived to predict the radial temperature distribution and its average over the surface of the disk as a function of system parameters. The model shows self-similarity of the temperature distribution and the existence of a dimensionless parameter S (ratio of heat flux to convection) that can be used as a criterion to optimize the thermal characteristics of the disk in order to approach uniform surface temperature. Comparison of the model to experimental data using global (infrared imager) and local (resistive temperature devices) measurements shows that agreement with the model depends on the ambient condition denoted by the local heat transfer coefficient.

Hypothermia is a well documented problem for surgical patients and is historically addressed by the use of a variety of warming aids and devices applied to the patient before, during, and after surgery. Their effectiveness is limited in many surgeries by practical constraints of surgical access, and hypothermia remains a significant concern. Increasing the temperature of the operating room has been proposed as an alternative solution. However, operating room temperatures must be cool enough to limit thermal stress on the surgical team despite the heat transport barriers imposed by protective sterile garments. Space technology in the form of the liquid cooling garment worn by EVA astronauts answers this need. Hamilton Sundstrand Space Systems International (HSSSI) has been working with Hartford Hospital to adapt liquid cooling garment technology for use by surgical teams in order to allow them to work comfortably in warmer operating room environments.

Hamilton Sundstrand has been working on the development of a new cryogenic flow boiler based on its patented compact, high-intensity cooler (CHIC) technology intended to provide low weight and volume and overcome freezing problems associated with cryogen use in EVA spacesuit cooling. Tests of the prototype device resulting from that effort have now been completed. The test data demonstrate that the design is extremely resistant to freezing the heat transport fluid as anticipated. Highly effective heat transfer is achieved in a compact device combining the functions of several conventional heat exchangers. This novel heat exchanger, a “normal flow” layered impingement arrangement should provide a very compact solution to any heat transfer applications where the cold fluid operates below the warm fluid's freezing point. Test results are generally consistent with design analyses for the prototype.

The International Space Station (ISS) IATCS (Internal Active Thermal Control System) includes two internal coolant loops that use an aqueous based coolant for heat transfer. A silver salt biocide was used initially as an additive in the coolant formulation to control the growth and proliferation of microorganisms in the coolant loops. Ground-based and in-flight testing has demonstrated that the silver salt is rapidly depleted and not effective as a long-term biocide. Efforts are now underway to select an alternate biocide for the IATCS coolant loop with greatly improved performance. An extensive evaluation of biocides was conducted to select several candidates for test trials.

This paper describes the New Shuttle Orbiter's Multi-Purpose Logistics Module (MPLM) Cargo Heat Exchanger (HX) and associated MPLM cooling system. Heat Exchanger (HX) design and system performance characteristics of the system are presented.

This study investigated pilots' taxi performance, situation awareness and workload while taxiing with three different head-up display (HUD) symbology formats: Command-guidance, Situation-guidance and Hybrid. Command-guidance symbology provided the pilot with required control inputs to maintain centerline position; Situation-guidance symbology provided conformal, scene-linked navigation information; while the Hybrid symbology combined elements of both symbologies. Taxi speed, centerline tracking accuracy, workload and situation awareness were assessed. Taxi speed, centerline accuracy, and situation awareness were highest and workload lowest with Situation-guidance and Hybrid symbologies. These results are thought to be due to cognitive tunneling induced by the Command-guidance symbology. The conformal route information of the Situation-guidance and Hybrid HUD formats provided a common reference with the environment, which may have supported better distribution of attention.

This paper summarizes the results to date of an on-going research program being conducted by NASA in conjunction with the FAA vertical flight program office. The goal of the program is to reduce pilot workload and increase safety for rotorcraft category A terminal area procedures. Two piloted simulations were conducted on the NASA Ames Vertical Motion Simulator to examine the benefits of optimal procedures, cockpit displays, and alternate cueing methods. Measures of performance, handling qualities ratings and pilot comments indicate that such enhancements can greatly assist a pilot in handling an engine failure in the terminal area.

The ISS (International Space Station) ITCS (Internal Thermal Control System) includes two internal coolant loops that utilize an aqueous based coolant for heat transfer. A silver salt biocide had previously been utilized as an additive in the coolant formulation to control the growth and proliferation of microorganisms within the coolant loops. Ground-based and in-flight testing demonstrated that the silver salt was rapidly depleted, and did not act as an effective long-term biocide. Efforts to select an optimal alternate biocide for the ITCS coolant application have been underway and are now in the final stages. An extensive evaluation of biocides was conducted to down-select to several candidates for test trials and was reported on previously.

This paper presents results of research on a solid waste dryer, based of the process of lyophilization, which recovers water and stabilizes solid waste. A lyophilizer has been developed and tested that uses thermoelectric heat pumps (TECs) to recycle heat during drying. The properties of TECs facilitate direct measurement of heat flow rates, and heat flow data are used to evaluate a heat and mass transfer model of the thermoelectric lyophilizer. Data are consistent with the theoretical model in most respects. Practical problems such as insulation and vacuum maintenance are minor in this system. However, the model’s assumption of a uniformly retreating ice layer during drying is valid only for the first 30% of water removed. Beyond this point, a shrinking core or lens model is more appropriate. Heat transfer to the shrinking core surrounded by dried material is slow.

An extremely compact heat exchanger is being developed which can boil cryogenic fluids with a liquid heat source at temperatures close to its freezing point. Freezing of the heat source fluid, e.g. water is precluded by the normal flow arrangement. Boiling and superheating of the cryogen occurs as the fluid approaches the heat source in a stack of bonded jet-array laminations. This heat exchanger technology is important in many applications where the storage of fluids at cryogenic temperatures offers substantial advantages in terms of system weight and volume. Often, as in several advanced portable life support system concepts, the advantages include the use of the cryogen as a heat sink in system thermal management. Realizing this benefit and safely conditioning the stored fluid for use requires effective heat transfer between the cryogen and a secondary heat transport fluid.

A suite of cockpit navigation displays for low-visibility airport surface operations has been designed by researchers at NASA Ames Research Center following a human-centered process. This paper reports on the final research effort in this process that examined the procedural integration of these technologies into the flight deck. Using NASA Ames' high-fidelity Advanced Concepts Flight Simulator, eighteen airline crews completed fourteen low-visibility (RVR 1000′) land-and-taxi scenarios that included both nominal (i.e., hold short of intersections, route amendments) and off-nominal taxi scenarios designed to assess how pilots integrate these technologies into their procedures and operations. Recommendations for integrating datalink and cockpit displays into current and future surface operations are provided.

The concept of free flight introduces many challenges for both air and ground aviation operations. Of considerable concern has been the issue of moving from centralized control and responsibility to decentralized control and distributed responsibility for aircraft separation. Data from capacity studies suggest that we will reach our capacity limits with ATC centralized control within the next 2 decades, if not sooner. Based on these predictions, research on distributed air-ground concepts was under taken by NASA Advanced Air Transportation Technologies Program to identify and develop air-ground concepts in support of free-flight operations. This paper will present the results of a full mission air-ground simulation conducted in the NASA Crew Vehicle Systems Research Facility. The purpose of the study was to evaluate the effect of advanced displays with “intent” (4-D flight plans) information on flight crew and ATC performance during limited free-flight operations.

Cockpit displays need to be substantially improved to serve the goals of situational awareness, conflict detection, and path replanning, in Free Flight. This paper describes the design of such an advanced cockpit display, along with an initial simulation based usability evaluation. Flight crews were particularly enthusiastic about color coding for relative altitude, dynamically pulsing predictors, and the use of 3-D flight plans for alerting and situational awareness.