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A review of the research accomplished in 2009 in the System-Level Design, Analysis and Simulation Tools (SLDAST) of the NASA's Airspace Systems Program is presented. This research thrust focuses on the integrated system-level assessment of component level innovations, concepts and technologies of the Next Generation Air Traffic System (NextGen) under research in the ASP program to enable the development of revolutionary improvements and modernization of the National Airspace System. The review includes the accomplishments on baseline research and the advancements on design studies and system-level assessment, including the cluster analysis as an annualization standard of the air traffic in the U.S. National Airspace, and the ACES-Air MIDAS integration for human-in-the-loop analyzes within the NAS air traffic simulation.

In February 2004 NASA released “The Vision for Space Exploration.” The important goals outlined in this document include extending human presence in the solar system culminating in the exploration of Mars. Unprocessed waste poses a biological hazard to crew health and morale. The waste processing methods currently under consideration include incineration, microbial oxidation, pyrolysis and compaction. Although each has advantages, no single method has yet been developed that is safe, recovers valuable resources including oxygen and water, and has low energy and space requirements. Thus, the objective of this project is to develop a low temperature oxidation process to convert waste cleanly and rapidly to carbon dioxide and water. In the Phase I project, TDA Research, Inc. demonstrated the potential of a low temperature oxidation process using ozone. In the current Phase II project, TDA and NASA Ames Research Center are developing a pilot scale low temperature ozone oxidation system.

Some selected segments of the ascent and the on-orbit data from the Space Shuttle flight, STS114, as well as some selected laboratory test article data have been analyzed using wavelets, power spectrum and autocorrelation function. Additionally, a simple approximate noise test was performed on these data segments to confirm the presence or absence of white noise behavior in the data. This study was initially directed at characterizing the on-orbit background against which a signature due to an impact during on-orbit operation could be identified. The laboratory data analyzed here mimic low velocity impact that the Orbiter may be subjected to during the very initial stages of ascent.

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.

A steady-state system mass balance calculation was performed to investigate design issues regarding the storage and/or processing of solid waste. In the initial stages of BIO-Plex, only a certain percentage of the food requirement will be satisfied through crop growth. Since some food will be supplied to the system, an equivalent amount of waste will accumulate somewhere in the system. It is a system design choice as to where the mass should accumulate in the system. Here we consider two approaches. One is to let solid waste accumulate in order to reduce the amount of material processing that is needed. The second is to process all of the solid waste to reduce solid waste storage and then either resupply oxygen or add physical/chemical (P/C) processors to recover oxygen from the excess carbon dioxide and water that is produced by the solid waste processor.

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.

The On-line Project Information System (OPIS) is a web-based database developed at NASA Ames Research Center (ARC) to improve information transfer and data availability for Exploration Life Support (ELS) projects. The tool enables users to investigate NASA technology development efforts, connect with knowledgeable experts, and to communicate important information. Within OPIS, Principal Investigators (PI's) post technical, administrative, and project participant information for other users to access through browse and search mechanisms. PI's are given technical data reporting requirements in the form of annual report templates, to assure that the information reported satisfies the most critical data needs of various ELS user groups. OPIS fulfills data and functionality needs of key user groups in the ELS Community through data solicitation, centralization, and distribution. The tool also circumvents data loss with ELS participant turnover.

Training to operate and manage Constellation vehicles, which include a crewed spacecraft and the lunar lander, is an essential part of the Constellation program. This paper discusses the on-going preparations for a Constellation Training Facility (CxTF). CxTF will be compromised of training simulators that will be used, in part, to prepare crew and flight controllers for vehicle operations. Current training simulators are reviewed to identify and outline key CxTF elements, i.e., part-task and full-task trainers. These trainers are further discussed within the context of the Constellation missions.

The “low power-CO2 removal (LPCOR) system” is an advanced air revitalization system that is under development at NASA Ames Research Center. The LPCOR utilizes the fundamental design features of the ‘four bed molecular sieve’ (4BMS) CO2 removal technology of the International Space Station (ISS). LPCOR improves power efficiency by replacing the desiccant beds of the 4BMS with a membrane dryer and a state-of-the-art, structured adsorbent device that collectively require 25% of the thermal energy required by the 4BMS desiccant beds for regeneration. Compared to the 4BMS technology, it has the added functionality to deliver pure, compressed CO2 for oxygen recovery. The CO2 removal and recovery functions are performed in a two-stage adsorption compressor. CO2 is removed from the cabin air and partially compressed in the first stage. The second stage performs further compression and delivers the compressed CO2 to a reduction unit such as a Sabatier reactor for oxygen recovery.

Designers of future space vehicles envision simplifying the Atmosphere Revitalization (AR) system by combining the functions of trace contaminant (TC) control and carbon dioxide removal into one swing-bed system. Flow rates and bed sizes of the TC and CO2 systems have historically been very different. There is uncertainty about the ability of trace contaminant sorbents to adsorb adequately in a high-flow or short bed length configurations, and to desorb adequately during short vacuum exposures. This paper describes preliminary results of a comparative experimental investigation into adsorbents for trace contaminant control. Ammonia sorbents and low temperature catalysts for CO oxidation are the foci. The data will be useful to designers of AR systems for Constellation. Plans for extended and repeated vacuum exposure of ammonia sorbents are also presented.

Dynamic simulation of the lunar outpost habitat life support was undertaken to investigate the impact of life support failures and to investigate possible responses. Some preparatory static analysis for the Lunar Outpost life support model, an earlier version of the model, and an investigation into the impact of Extravehicular Activity (EVA) were reported previously. (Jones, 2008-01-2184, 2008-01-2017) The earlier model was modified to include possible resupply delays, power failures, recycling system failures, and atmosphere and other material storage failures. Most failures impact the lunar outpost water balance and can be mitigated by reducing water usage. Food solids and nitrogen can be obtained only by resupply from Earth. The most time urgent failure is a loss of carbon dioxide removal capability. Life support failures might be survivable if effective operational solutions are provided in the system design.

In February 2004 NASA released “The Vision for Space Exploration.” The goals outlined in this document include extending the human presence in the solar system, culminating in the exploration of Mars. A key requirement for this effort is to identify a safe and effective method to process waste. Methods currently under consideration include incineration, microbial oxidation, pyrolysis, drying, and compaction. Although each has advantages, no single method has yet been developed that is safe, recovers valuable resources including oxygen and water, and has low energy and space requirements. Thus, the objective of this work was to develop a low temperature oxidation process to convert waste cleanly and rapidly to carbon dioxide and water. TDA and NASA Ames Research Center have developed a pilot scale low temperature ozone oxidation system to convert organic waste to CO2 and H2O.

Design, operations and maintenance activities in aviation involve analysis of variety of aviation data. This data is typically in disparate formats making it difficult to use with different software packages. Use of a self-describing and extensible standard called XML provides a solution to this interoperability problem. While self-describing nature of XML makes it easy to reuse, it also increases the size of data significantly. A natural solution to the problem is to compress the data using suitable algorithm and transfer it in the compressed form. We found that XML-specific compressors such as Xmill and XMLPPM generally outperform traditional compressors. However, optimal use of Xmill requires of discovery of optimal options to use while running Xmill. Manual discovery of optimal setting can require an engineer to experiment for weeks.

The current CO2 removal technology of NASA is very energy intensive and contains many non-optimized subsystems. This paper discusses the concept of a next-generation, membrane-integrated, adsorption processor for CO2 removal and compression in closed-loop air revitalization systems. The membrane module removes water from the feed, passing it directly into the processor's exhaust stream; it replaces the desiccant beds in the current four-bed molecular sieve system, which must be thermally regenerated. Moreover, in the new processor, CO2 is removed and compressed in a single two-stage unit. This processor will use much less power than NASA's current CO2 removal technology and will be capable of maintaining a lower CO2 concentration in the cabin than that can be achieved by the existing CO2 removal systems.

A generalized computer program for analysis of pressure and composition in multiple volume systems has been under development by the National Aeronautics and Space Administration (NASA) since 1976. This paper describes the most recent developments in the program. These improvements include the expansion of the program to nine volumes, improvements to the model of the International Space Station (ISS) carbon dioxide removal system, and addition of a detailed Sabatier carbon dioxide reduction mode. An evaluation of the feasibility of adding of trace contaminant tracking was also performed. This paper will also present the results of an analysis that compares model predictions with ISS flight data for carbon dioxide (CO2) maintenance.

A closed-loop air revitalization system requires continuous removal of CO2 from the breathing air and an oxygen recovery system to recover oxygen from the waste CO2. Production of oxygen from CO2 is typically achieved by reacting CO2 with hydrogen in a reduction unit such as a Sabatier reactor. The air revitalization system of International Space Station (ISS) currently operates on an open loop mode where CO2 is being vented into the space vacuum due to lack of a Sabatier Reactor. A compressor and a storage device are required to interface the Carbon Dioxide Removal Assembly (CDRA) and the Sabatier reactor. This compressor must acquire the low-pressure CO2 from CDRA and provide it at a high enough pressure to the Sabatier reactor. The compressor should ensure independent operations of CDRA and Sabatier reactor at all times, even when their operating schedules are not synchronized.

Of the many competing technologies for resource recovery from solid wastes for long duration manned missions such as a lunar or Mars base, incineration technology is one of the most promising and certainly the most well developed in a terrestrial sense. Various factors are involved in the design of an optimum fluidized bed incinerator for inedible biomass. The factors include variability of moisture in the biomass, the ash content, and the amount of fuel nitrogen in the biomass. The crop mixture in the waste will vary; consequently the nature of the waste, the nitrogen content, and the biomass heating values will vary as well. Variation in feed will result in variation in the amount of contaminants such as nitrogen oxides that are produced in the combustion part of the incinerator. The incinerator must be robust enough to handle this variability. Research at NASA Ames Research Center using the fluidized bed incinerator has yielded valuable data on system parameters and variables.

We modeled BIO-Plex designs with separate or combined atmospheres and then simulated controlling the atmosphere composition. The BIO-Plex is the Bioregenerative Planetary Life Support Systems Test Complex, a large regenerative life support test facility under development at NASA Johnson Space Center. Although plants grow better at above-normal carbon dioxide levels, humans can tolerate even higher carbon dioxide levels. Incinerator exhaust has very high levels of carbon dioxide. An elaborate BIO-Plex design would maintain different atmospheres in the crew and plant chambers and isolate the incinerator exhaust in the airlock. This design option easily controls the crew and plant carbon dioxide levels but it uses many gas processors, buffers, and controllers. If all the crew’s food is grown inside BIO-Plex, all the carbon dioxide required by the plants can be supplied by crew respiration and the incineration of plant and food waste.

Samples of Mars surface material will return to Earth in 2014. Prior to curation and distribution to the scientific community the returned samples will be isolated in a special facility until their biological safety has been assessed following protocols established by NASA’s Planetary Protection Office. The primary requirements for the pre-release handling of the Martian samples include protecting the samples from the Earth and protecting the Earth from the sample. A testbed will be established to support the design of such a facility and to test the planetary protection protocols. One design option that is being compared to the conventional Biological Safety Level 4 facility is a double walled differential pressure chamber with airlocks and automated equipment for analyzing samples and transferring them from one instrument to another.

New variable environment Modified Energy Cascade (MEC) crop models were developed for all the Advanced Life Support (ALS) candidate crops and implemented in SIMULINK. The MEC models are based on the Volk, Bugbee, and Wheeler Energy Cascade (EC) model and are derived from more recent Top-Level Energy Cascade (TLEC) models. The MEC models were developed to simulate crop plant responses to day-to-day changes in photosynthetic photon flux, photoperiod, carbon dioxide level, temperature, and relative humidity. The original EC model allowed only changes in light energy and used a less accurate linear approximation. For constant nominal environmental conditions, the simulation outputs of the new MEC models are very similar to those of earlier EC models that use parameters produced by the TLEC models. There are a few differences. The new MEC models allow setting the time for seed emergence, have more realistic exponential canopy growth, and have corrected harvest dates for potato and tomato.