Development of Plastic Melt Waste Compactor for Space Missions - Experiments and Prototype Design

<div class="htmlview paragraph">The Lithium Hydroxide (LiOH) management plan to control carbon dioxide (CO<sub>2</sub>) for the Shuttle while docked to the International Space Station (ISS) reduces the mass and volume needed to be launched. For missions before Flight UF-1/STS-108, the Shuttle and ISS each removed their own CO<sub>2</sub> during the docked time period. To control the CO<sub>2</sub> level, the Shuttle used LiOH canisters and the ISS used the Vozdukh or the Carbon Dioxide Removal Assembly (CDRA) with the Vozdukh being the primary ISS device for CO<sub>2</sub> removal. Analysis predicted that both the Shuttle and Station atmospheres could be controlled using the Station resources with only the Vozdukh and the CDRA. If the LiOH canisters were not needed for the CO<sub>2</sub> control on the Shuttle during the docked periods, then the mass and volume from these LiOH canisters normally launched on the Shuttle could be replaced with other cargo. On the Flight UF-1/STS-108 mission, a Station Detailed Test Objective (SDTO) showed the feasibility that both the Shuttle and Station atmospheres could be controlled using the Station resources.</div> <div class="htmlview paragraph">This paper will discuss the methods and their priority for removing CO<sub>2</sub>, how CDRA operations affect the plan, the sources of the LiOH canisters, the results of the SDTO, the performance and lifetime of the LiOH canisters, rotations plans, stowage issues, and future plans.</div>

<div class="htmlview paragraph">Significant progress has been made at NASA Ames Research Center in the development of a heat melt compaction device called the Plastic Melt Waste Compactor (PMWC). The PMWC was designed to process wet and dry wastes generated on human space exploration missions. The wastes have a plastic content typically greater than twenty percent. The PMWC removes the water from the waste, reduces the volume, and encapsulates it by melting the plastic constituent of the waste. The PMWC is capable of large volume reductions. The final product is compacted waste disk that is easy to manage and requires minimal crew handling. This paper describes the results of tests conducted using the PMWC with a wet and dry waste composite that was representative of the waste types expected to be encountered on long duration human space exploration missions.</div>

An intelligent system that schedules Space Shuttle activities

<div class="htmlview paragraph">The development of virtual environment technology at NASA Ames Research Center and other research institutions has created opportunities for enhancing human performance. The application of this technology to training astronaut flight crews planning to go onboard the International Space Station has already begun at the NASA Johnson Space Center. A unique application of virtual environments to crew training is envisioned at NASA Ames Research Center which combines state of the art technology with haptic feedback to create a method for training crewmembers on critical life sciences operations which require fine motor skills. This paper describes such a concept, known as the Virtual Glovebox, as well as surveys other applications of virtual environments to astronaut crew training.</div>

<div class="htmlview paragraph">The Waste and Hygiene Compartment will serve as the primary facility for metabolic waste management and personal hygiene on the United States segment of the International Space Station. The Compartment encloses the volume of two standard ISS racks and will be installed into Node 3 after launch inside a Multipurpose Logistics Module on the Space Shuttle. Long duration space flight requires a departure from the established hygiene and waste disposal practices employed on the Space Shuttle. This paper describes requirements and a conceptual design for the Waste and Hygiene Compartment that are both logistically practical and acceptable to the crew.</div>

<div class="htmlview paragraph">Testing of the International Space Station (ISS) U.S. Laboratory baseline configuration of the Atmosphere Revitalization Subsystem (ARS) by NASA's Marshall Space Flight Center (MSFC) has been conducted as part of the Environmental Control and Life Support System (ECLSS) design and development program. This testing addressed specific questions with respect to the control and performance of the baseline ARS subassemblies in the ISS U.S. Laboratory configuration. The test used pressurized oxygen injection, a mass spectrometric major constituent analyzer (MCA), a four-bed molecular sieve carbon dioxide removal assembly (CDRA), and a trace contaminant control subassembly (TCCS) to maintain the atmospheric composition in a sealed chamber within ISS specifications. Human metabolic processes for a crew of four are simulated according to projected ISS mission timelines.</div> <div class="htmlview paragraph">The Integrated ARS Test (IART) builds upon previous integrated ECLSS testing conducted at MSFC between 1987 and 1992. The IART is designed to address ARS control and performance issues that are peculiar to the ISS. These issues resulted from the ISS ECLSS configuration development, design requirement changes since 1992, and the increased maturity of each ARS subassembly's design. IART test objectives, facility design, pretest analyses, test and control requirements, and test results are presented.</div>

Developing a software system for mission planners at NASA’s Johnson Space Center (JSC) to plan and schedule activities onboard the Space Shuttle or International Space Station (ISS) is a complex task. Due to the scope of the complete user requirements and budget restrictions, a full development of all capabilities was not practical. The planning system had to include not only capabilities for planning the daily activities onboard the spacecraft, but also had to include the capability to upload the plans to the onboard system and to merge plans and activities from planners at other remote planning centers, including Marshall Space Flight Center (MSFC) and International Partners. The Integrated Planning System (IPS) Consolidated Planning System (CPS) was developed in an incremental fashion to continually meet the most immediate needs for the users. CPS has been under development for over 8 years and has been operational at JSC for 5 years, supporting Space Shuttle Program (SSP) and ISS mission planning. The journey to this point of software capabilities has been slow, but steady. The current size of the software application is over 380 K SLOC. Initial development focused on capability for scheduling SSP missions, as this was the most immediate need. Next, the development focused on ISS capability, such as plan upload and advanced long-range planning techniques. Finally, the development focused on including/merging data from MSFC and the International Partners. This paper documents some of the “Lessons Learned” during the development of the CPS. Some examples of these include: • Focusing on current operational needs creates system requirements that may not be applicable in future operations • File exchange mechanism uses a proprietary file format that is not flexible to change • Size and quantity of current planning data seriously hampers performance of the system • Incremental approach to development adds new functionality as peripheral to core functionality The nature of “Lessons Learned” tends to focus our attention on deficiencies in the software. We look at actions or functionality that could have been implemented better or planned better. Focusing on these may give the reader the false impression that the CPS is a short sighted, unusable system. However, the system is stable and quite comprehensive in its capabilities for planning current ISS and SSP operations. The incremental approach allowed the development team to tailor the software to shifting user requirements as planning user operations scenarios and requirements changed. Overall, the CPS is an excellent planning system. This paper is intended to provide some assistance in a “path through the mine field” of software development for planning space mission operations. It is hoped that these “Lessons Learned” can be applied in future space mission planning system projects to avoid some of the limitations of the current system.

<div class="htmlview paragraph">The Columbus laboratory module, developed by Astrium Bremen as prime contractor and Alenia Spazio as co-prime, is the European contribution to the International Space Station (ISS) program and as such it will support, once in orbit, micro-gravity and space based research activities of the member states.</div> <div class="htmlview paragraph">Columbus Environmental Control System (ECS) employs an Environmental Control and Life Support System (ECLSS) providing atmosphere pressure, cabin ventilation and temperature humidity control inside the module in conjunction with an autonomous Active Thermal Control System (ATCS) that provides the heat collection capability. The ATCS, based on software controlled water loop, provides also the cooling capability for Payloads and Subsystem equipment. The ECS is completed with the Passive Thermal Control System based on software controlled shell heating system plus passive fixtures such as Multi-Layers Insulation (MLI) blankets.</div> <div class="htmlview paragraph">Generally, both, the Columbus ATCS as well as the ECLSS are qualified via simplified but representative tests and concluding analyses. Complete verification of the module thermal and environmental control design however, will be performed via analysis supported by ECS System Level Integrated Test as well as the predictions for flight.</div> <div class="htmlview paragraph">With respect to responsibility sharing, Alenia is responsible for all verification by test related to thermal/environmental aspects, i.e. Alenia will define the test requirements and cases to be performed via the establishment of a dedicated test specification. On the other side, definition and production of the test set-up as well as the performance of the test is assigned to the Columbus prime Astrium SI Bremen.</div> <div class="htmlview paragraph">In order to get confidence on the functional performance of the Columbus ECS and to validate the Integrated Overall Thermal Mathematical Model (IOTMM) on system level the module will be subjected to an Integrated System Test (IST).</div> <div class="htmlview paragraph">Purpose of the ECS IST is to provide the first verification of the thermal/environmental interrelation between the active cooling (ATCS) and environmental control system (ECLSS) hardware and software and to collect as much characteristic thermal data as possible for the validation of the flight configuration IOTMM. This test will represent the second and last test in series on the flight configuration of the Columbus module.</div> <div class="htmlview paragraph">Previous tests, for verification of the functional interfaces of the ATCS and ECLSS, have been performed already in the frame of the Electrical Test Model (ETM) utilization. However, this test did not provide information on environmental and thermal parameters of the system but rather on the functional interrelations of the relevant units of the subsystems. Presently, the subject test will be performed in the integration hall of Astrium SI Bremen (Class 100.000 clean room conditions) and the pressurized shell is planned to be covered by the flight multi-layer insulation only located beneath the meteoroid debris panels (MDPS) of the module. However, in order to get as much as possible characteristic data of the system not only the test cases have to be selected very carefully but also additional test supporting equipment (TSE) has to be evaluated.</div> <div class="htmlview paragraph">The present paper summarizes the efforts generated to establish the Environmental/Thermal test in the frame of the system level IST of the Columbus module, describes the interrelation aspects of the thermal/environmental subsystem verification by test and analysis and presents the derived methodologies and expected results.</div>

<div class="htmlview paragraph">The International Space Station (ISS) Environmental Control and Life Support (ECLS) System is continuing to be integrated with a multitude of international partner contributions. In six short months, ISS integrates ECLS systems with the Node 2, Columbus module, Japanese Logistics Module, and Automated Transfer Vehicle developed and produced by the European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA). The new systems provide both international unique hardware and common ISS hardware.</div> <div class="htmlview paragraph">An overview of the integrated ECLS system and the unique capabilities of each new module is provided. A spreadsheet of the common hardware and locations is provided. An overview of the on-orbit operations is provided.</div> <div class="htmlview paragraph">Adding the international partner systems makes a robust ISS ECLS system. More U.S. hardware will continue to be launched to enhance the ECLS six crew capability.</div>

<div class="htmlview paragraph">In the past decade, the space shuttle has been the key factor for the United States manned space exploration. In fact the space shuttle is the only means in which the United States government can send humans into space. However, the space shuttle's life-expectancy is due to expire around the year 2005. In preparation for the end of the space shuttle era, we, as a country, must decide what type of future space vehicle is appropriate to accomplish our future national goals in space.</div> <div class="htmlview paragraph">There are many public policy alternatives to the question: ‘What will replace the space shuttle?’ First, the United States could try a conservative approach to space exploration by developing and using an unmanned vehicle. Second, the government could opt for utility by developing a mixed fleet of launch vehicles. Third, the United States could try to modify and update the current space shuttles with new technology. Fourth, the United States could choose to invest its money in more ‘exotic’ space vehicle programs such as the Single-Stage-To-Orbit(SSTO) space plane and the Two-Stage-To-Orbit(TSTO) space plane. Lastly, the United States could try to initiate talks with other countries concerning an international space agency that could pool the finances and resources into one unified space program.</div> <div class="htmlview paragraph">In my final recommendation, I would first look into a possible international cooperation for future funding and operation of space transportation. However, if this first objective is unable to produce any type of cooperation within a couple of years, I would initiate a parallel future space vehicle program that would involve most of the modification of the space shuttle option and all of the mixed fleet option. Along with these main public policy recommendations, I also recommend some administrative suggestions that could prove vital in trying to carry out the public policy of future space vehicles.</div>

<div class="htmlview paragraph">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.</div> <div class="htmlview paragraph">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. We are conducting tests in a reactor design that maximizes the contact between the ozone and the waste bed. In initial tests with a large volume reactor we were able to achieve higher oxidation rates than we obtained in the Phase I portion of this project. However, on occasion, the waste began to burn rapidly, producing high temperature and pressure spikes in the reactor. Therefore, we redesigned the reactor to mitigate the rapid ignition of the waste. In initial tests, we found that adding water to the waste bed and flowing ozone through the water-waste mixture provides much better control of the low temperature oxidation process. The addition of water likely produces a more uniform temperature throughout the waste, reducing localized hot spots that initiated the rapid combustion process. In addition, we have obtained better agreement between the gravimetric data and the results calculated with integrated CO<sub>2</sub> data, indicating that a higher percentage of waste has been oxidized to CO<sub>2</sub> and H<sub>2</sub>O before exiting the reactor.</div> <div class="htmlview paragraph">Once we have optimized the reactor design and waste oxidation process we will incorporate the design into a closed loop, fully automated system that will convert the waste into H<sub>2</sub>O and CO<sub>2</sub>, remove both compounds, and replenish the circulating gas stream with oxygen and ozone as needed. In addition, the system will contain the analytical equipment necessary to carry out a complete material balance and monitor the formation of pollutants such as NO<sub>X</sub> and SO<sub>X</sub>. At the conclusion of the project the system will be delivered to NASA Ames for their use and evaluation.</div>

<div class="htmlview paragraph">To address basic cell biology questions such as “Can cells respond to a gravity stimulus?”, a Cell Culture Unit (CCU) is being developed for use in the International Space Station. The CCU will accommodate diverse specimen types (animal, plant, and microbial cells; tissues; aquatic organisms) in up to twenty-four cell specimen chambers. The environmental conditions (e.g. temperature, pH, gas concentrations) will be maintained by medium recirculation and renewal, and gas and heat exchange. The CCU will also provide for the addition of experimental agents (e.g. growth factors), automated sampling, and monitoring of the specimens by video microscopy. Microgravity experiments will be performed using the CCU within the Habitat Holding Rack (HHR); a CCU within the Space Station Centrifuge will serve as an on-board unit-gravity control.</div> <div class="htmlview paragraph">The CCU design includes a Cell Specimen Environment Assembly to maintain the specimens, a Video Microscope System to obtain specimen images, an Electronics Assembly to control the subsystems and provide signal conditioning, a Power Supply Subsystem to condition power from the HHR or Centrifuge, an Active Cooling Subsystem to maintain specimen temperature, and a Structural Containment Assembly to house the subsystems and interface with the HHR or Centrifuge. Six reference specimens, encompassing the candidates that will likely be flown and that exercise the required ranges of experimental conditions, were selected to test the individual subsystems and the CCU system. Here we report the design and development testing of the first CCU prototypes (e.g. biocompatibility, medium flow and mixing, gas exchange, sampling, video images, cell and tissue culture). Detailed design and testing will continue towards a first launch of the CCU in 2001.</div>

<div class="htmlview paragraph">NASA's current vision for exploration dictates that radiators for a Crew Exploration Vehicle (CEV), a Lunar Surface Access Module (LSAM), and a lunar base will need to be developed. These applications present new challenges when compared to previous radiators on the Space Shuttle and International Space Station (ISS). In addition, many technological advances have been made that could positively impact future radiator design. This paper outlines new requirements for future radiators and documents a trade study performed to select some promising technologies for further evaluation. These technologies include carbon composites substrates as well as Optical Solar Reflectors (OSRs), a lithium based white paint, and electrochromic thin films for optical coatings.</div>

<div class="htmlview paragraph">NASA's Constellation Program, which includes the mission objectives of establishing a permanently-manned lunar Outpost, and the exploration of Mars, poses new and unique challenges for human life support systems that will require solutions beyond the Shuttle and International Space Station state of the art systems. In particular, the requirement to support crews for extended durations at the lunar outpost with limited resource resupply capability will require closed-loop regenerative life support systems with minimal expendables. Planetary environmental conditions such as lunar dust and extreme temperatures, as well as the capability to support frequent and extended-duration Extra-vehicular Activity's (EVA's) will be particularly challenging. This paper will discuss the NASA Constellation Program missions, phases, and major elements, and will discuss the state of the art technologies used in prior programs such as Apollo, Skylab, Space Shuttle, and International Space Station as a point of reference. New Constellation requirements driving technologies over prior programs and architectures will be discussed, including (but not limited to) lunar “anywhere access”, the construction of a permanently-crewed lunar outpost, growth in lunar crew size over Apollo, EVA requirements, challenges of lunar dust, and significant vehicle weight challenges. Although the Constellation requirements for the lunar mission phase and beyond are still under development by NASA, they will push the technology beyond the current state of the art. These life support technology development needs resulting from new mission requirements and architecture constraints will be addressed and prioritized.</div>

<div class="htmlview paragraph">Developed as part of the suite of Space Station Biological Research Project (SSBRP) hardware to support research aboard the International Space Station (ISS), the Incubator is a temperature-controlled chamber for conducting life science research with small animal, plant and microbial specimens. The Incubator is designed for use only on the ISS and is transported to/from the ISS, unpowered and without specimens, in the Multi-Purpose Logistics Module (MPLM). The Incubator interfaces with the three SSBRP Host Systems; the Habitat Holding Racks (HHR), the Life Sciences Glovebox (LSG) and the 2.5 m Centrifuge Rotor (CR), providing investigators with the ability to conduct research in microgravity and at variable gravity levels of up to 2-g.</div> <div class="htmlview paragraph">The temperature within the Specimen Chamber can be controlled between 4° and 45<sup>o</sup>C. Cabin air is recirculated within the Specimen Chamber and can be exchanged with the ISS cabin at a rate of ≈ 50 cc/min. The humidity of the Specimen Chamber is monitored. The Specimen Chamber has a usable volume of ≈ 19 liters and contains two (2) connectors at 28v dc (60W) for science equipment; 5 dedicated thermometers for science; ports to support analog and digital signals from experiment unique sensors or other equipment; an Ethernet port; and a video port. It is currently manifested for UF-3 and will be integrated within the first SSBRP Habitat Holding Rack for launch.</div>