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When the demand for either a region of airspace or an airport approaches or exceeds the available capacity, miles-in-trail (MIT) restrictions are the most frequently issued traffic management initiatives (TMIs) that are used to mitigate these imbalances. Miles-in-trail operations require aircraft in a traffic stream to meet a specific inter-aircraft separation in exchange for maintaining a safe and orderly flow within the stream. This stream of aircraft can be departing an airport, over a common fix, through a sector, on a specific route or arriving at an airport. This study begins by providing a high-level overview of the distribution and causes of arrival MIT restrictions for the top ten airports in the United States. This is followed by an in-depth analysis of the frequency, duration and cause of MIT restrictions impacting the Hartsfield-Jackson Atlanta International Airport (ATL) from 2009 through 2011.

Scheduled arriving aircraft demand may exceed airport arrival capacity when there is abnormal weather at an airport. In such situations, Federal Aviation Administration (FAA) institutes ground-delay programs (GDP) to delay flights before they depart from their originating airports. Efficient GDP planning depends on the accuracy of prediction of airport capacity and demand in the presence of uncertainties in weather forecast. This paper presents a study of the impact of dynamic airport surface weather on GDPs. Using the National Traffic Management Log, effect of weather conditions on the characteristics of GDP events at selected busy airports is investigated. Two machine learning methods are used to generate models that map the airport operational conditions and weather information to issued GDP parameters and results of validation tests are described.

The operation of a crop growth system in micro-gravity is an important part of the National Aeronautics and Space Administration's Closed Ecological Life Support System development program. Maintaining densely arrayed plants in a closed environment imposed to induce high growth rates must be expected to result in substantial levels of water transpiration rate. Since the environmental air is recirculated, the transpiration water must be removed. In an operating CELSS, it is expected that this water will provide potable water for use of the crew. There is already considerable knowledge about water removal from crew environmental air during orbital and transfer activities, and the difference between the conditions of the described requirement and the conditions for which experience has been gained is the quantities involved and the reliability implications due to the required periods of operation.

This paper features a set of advanced technologies for autonomy and intelligence in advanced inspection systems of facility operations. These technologies offer a significant contribution to set a path to establish a system and an operating environment with autonomy and intelligence for inspection, monitoring and safety via gas and ambient sensors, video mining and speech recognition commands on unmanned ground vehicles and other platforms to support operational activities in the Cryogenics Test bed and other facilities and vehicles. These advanced technologies are in current development and progress and their functions and operations require guidance and formulation in conjunction with the development team(s) toward the system architecture.

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.

The least expensive life support for brief human missions is direct supply of all water and oxygen from Earth without any recycling. The currently most advanced human life support system was designed for the International Space Station (ISS) and will use physicochemical systems to recycle water and oxygen. This paper compares physicochemical to direct supply air and water life support systems using Equivalent Mass (EM). EM breakeven dates and EM ratios show that physicochemical systems are more cost effective for longer mission durations.

Waste management is a vital function of spacecraft life support systems as it is necessary to meet crew health and safety and quality of life requirements. Depending on the specific mission requirements, waste management operations can include waste collection, segregation, containment, processing, storage and disposal. For the Crew Exploration Vehicle (CEV), addressing volume and mass constraints is paramount. Reducing the volume of trash prior to storage is a viable means to recover habitable volume, and is therefore a particularly desirable waste management function to implement in the CEV, and potentially in other spacecraft as well. Research is currently being performed at NASA Ames Research Center to develop waste compaction systems that can provide both volume and mass savings for the CEV and other missions.

Waste management is a critical component of life support systems for manned space exploration. Human occupied spacecraft and extraterrestrial habitats must be able to effectively manage the waste generated throughout the entire mission duration. The requirements for waste systems may vary according to specific mission scenarios but all waste management operations must allow for the effective collection, containment, processing, and storage of unwanted materials. NASA's Crew Exploration Vehicle usually referred to as the CEV, will have limited volume for equipment and crew. Technologies that reduce waste storage volume free up valuable space for other equipment. Waste storage volume is a major driver for the Orion waste compactor design. Current efforts at NASA Ames Research Center involve the development of two different prototype compactors designed to minimize trash storage space.

This study introduces several new concepts for suited EVA astronaut ingress/egress (departure and return) from a pressurized planetary surface habitat, based on use of a rear-entry suit and a suit lock or suitport. We provide insight into key operational aspects and integration issues, as well as the results of a requirements analysis and risk assessment of the concepts. The risk assessment included hazard analysis, hazard mitigation techniques, failure mode assessment, and operational risk assessment. Also included are performance and mass estimates for the egress concepts, and concepts for integration of the egress concepts with potential planetary habitat designs.

This paper considers the design of a life support system for transit to Mars and return to Earth. Because of the extremely high cost of launching mass to Mars, the Mars transit life support system must minimize the amount of oxygen, water, and food transported. The three basic ways to provide life support are to directly supply all oxygen and water, or to recycle them using physicochemical equipment, or to produce them incidentally while growing food using crop plants. Comparing the costs of these three approaches shows that physicochemical recycling of oxygen and water is least costly for a Mars transit mission. The long mission duration also requires that the Mars transit life support system have high reliability and maintainability. Mars transit life support cannot make use of planetary resources or gravity. It should be tested in space on the International Space Station (ISS).

Terraforming of Mars is the long-term goal of colonization of Mars. However, this process is likely to be a very slow process and conservative estimates involving a synergetic, technocentric approach suggest that it may take around 10,000 years before the planet can be parallel to that of Earth and where humans can live in open systems (Fogg, 1995). Hence, for the foreseeable future, any missions will require habitation within small confined habitats with high biomass to atmospheric mass ratios, thereby requiring that all wastes be recycled. Processing of the wastes will ensure predictability and reliability of the ecosystem and reduce resupply logistics. Solid wastes, though smaller in volume and mass than the liquid wastes, contain more than 90% of the essential elements required by humans and plants.

A habitat for housing up to 32 Tenebrionid, black body beetles (Trigonoscelis gigas Reitter) has been developed at Ames Research Center for conducting studies to evaluate the effects of long duration spaceflight upon insect circadian timing systems. This habitat, identified as the Beetle Kit, provides an automatically controlled lighting system and activity and temperature recording devices, as well as individual beetle enclosures. Each of the 32 enclosures in a Beetle Kit allows for ad lib movement of the beetle as well as ventilation of the beetle enclosure via an externally operated hand pump. Two Beetle Kits were launched on STS-84 (Shuttle-Mir Mission-06) on May 15, 1997 and were transferred to the Priroda module of the Russian Mir space station on May 18 as part of the NASA/Mir Phase 1 Science Program. Following the Progress collision with Spektr on June 25, the Kits were transferred to the Kristall module. The beetles will remain on Mir for approximately 135 days.

This study examines the current state of the art in rodent habitats as well as the next generation of rodent habitats currently under development at NASAs Ames Research Center. Space Shuttle missions are currently limited in duration to just over two weeks. In contrast to this, future life science missions aboard the Space Station may last months or even years. This will make resource conservation and utilization critical issues in the development of rodent habitats for extended microgravity missions. Emphasis is placed on defining rodent requirements for extended space flights of up to 90 days, and on improving habitability and extending the useful performance life of rodent habitats.

An innovative design that meets both Shuttle and Space Station requirements for a user-friendly, volume-efficient, portable glovebox system has been developed at Ames Research Center (ARC). The Standard Interface Glovebox (SIGB) has been designed as a two Middeck locker-sized system that mounts in a Middeck Rack Structure (MRS) or in any rack using the Standard Interface Rack (SIR) rail spacing. The MRS provides structural support for the SIGB during all aspects of the mission and is an interface consistent with NASA's desire for commonality of mechanical interfaces, allowing the SIGB to be flown on essentially any manned space platform. The SIGB provides an enclosed work volume which operates at negative pressure relative to ambient, as well as excellent lighting and ample work volume for anticipated life sciences-related experiment operations inflight.

For the last two years, the University of Utah and Reaction Engineering International, in cooperation with NASA Ames Research Center (ARC), have been developing a waste incineration system for regenerative life support systems. The system is designed to burn inedible plant biomass and human waste. The goal is to obtain an exhaust gas clean enough to recycle to either the plant or human habitats. The incineration system, a fluidized bed reactor, has been designed for a 4-person mission. This paper will detail the design of the units. In addition, results will be presented from testing at the University of Utah. Presently, the unit has been shipped to Ames Research Center for more tests prior to delivery to Johnson Space Center for testing in a 90-day, 4-person test.

PGBA, a plant growth facility developed for commercial space biotechnology research, successfully grew a total of 50 plants (6 species) during 10 days aboard the Space Shuttle Endeavor (STS-77), and has reflown aboard the Space Shuttle Columbia (STS-83 for 4 days and STS-94 for 16 days) with 55 plants and 10 species. The PGBA life support system provides atmospheric, thermal, and humidity control as well as lighting and nutrient supply in a 33 liter microgravity plant growth chamber. The atmosphere treatment system removes ethylene and other hydrocarbons, actively controls CO2 replenishment, and provides passive O2 control. Temperature and humidity are actively controlled.

This paper offers a concept for a regenerable, low-power system for purifying exhaust from a solid waste processor. The innovations in the concept include the use of a closed-loop regeneration cycle for the adsorber, which prevents contaminants from reaching the breathable air before they are destroyed, and the use of a humidity-swing desorption cycle, which uses less power than a thermal desorption cycle and requires no venting of air and water to space vacuum or planetary atmosphere. The process would also serve well as a trace contaminant control system for the air in the closed environment. A systems-level design is presented that shows how both the exhaust and air purification tasks could be performed by one processor. Data measured with a fixed-bed apparatus demonstrate the effects of the humidity swing on regeneration of the adsorbent.

The Plant Generic BioProcessing Apparatus (PGBA), a plant growth facility developed for commercial space biotechnology research, has flown successfully on 3 spaceflight missions for 4, 10 and 16 days. The environmental control systems of this plant growth chamber (28 liter/0.075 m2) provide atmospheric, thermal, and humidity control, as well as lighting and nutrient supply. Typical performance profiles of water transpiration and dehumidification, carbon dioxide absorption (photosynthesis) and respiration rates in the PGBA unit (on orbit and ground) are presented. Data were collected on single and mixed crops. Design options and considerations for the different sub-systems are compared with those of similar hardware.

This paper compares four potential water treatment systems in the context of their applicability to a Mars transit vehicle mission. The systems selected for evaluation are the International Space Station system, a JSC bioreactor-based system, the vapor phase catalytic ammonia removal system, and the direct osmotic concentration system. All systems are evaluated on the basis of their applicability for use in the context of the Mars Reference Mission. Each system is evaluated on the basis of mass equivalency. The results of this analysis indicate that there is effectively no difference between the International Space Station system and the JSC bioreactor configurations. However, the vapor phase catalytic ammonia removal and the direct osmotic concentration systems offer a significantly lower mass equivalency (approximately 1/7 the ISS or bioreactor systems).

Ames Research Center's Life Sciences Division was responsible for managing the development of fundamental biology flight experiments during the Phase 1 NASA/Mir Science Program. Beginning with astronaut Norm Thagard's historic March, 1995 Soyuz rendezvous with the Mir station and continuing through Andy Thomas' successful return from Mir onboard STS-91 in June, 1998, the NASA/Mir Science Program has provided scientists with unparalleled long duration research opportunities. In addition, the Phase 1 program has yielded many valuable lessons to program and project management personnel who are managing the development of future International Space Station payload elements. This paper summarizes several of the key space station challenges faced and associated lessons learned by the Ames Research Center Fundamental Biology Research Project.