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This study was performed to aide in the creation of design requirements for the next generation of space suits that more accurately describe the level of mobility necessary for a suited crewmember through the use of an innovative methodology utilizing functional mobility. A novel method was utilized involving the collection of kinematic data while 20 subjects (10 male, 10 female) performed pertinent functional tasks that will be required of a suited crewmember during various phases of a lunar mission. These tasks were selected based on relevance and criticality from a larger list of tasks that may be carried out by the crew. Kinematic data was processed through Vicon BodyBuilder software to calculate joint angles for the ankle, knee, hip, torso, shoulder, elbow, and wrist. Maximum functional mobility was consistently lower than maximum isolated mobility.

Silver biocide offers a potential advantage over iodine, the current state-of-the-art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. As such, silver may reduce the overall complexity and mass of future spacecraft potable water systems, particularly those used to support long duration missions. A primary technology gap identified for the use of silver biocide is one of material compatibility. Wetted materials of construction are required to be selected such that silver ion concentrations can be maintained at biocidally effective levels.

Carbosieve SIII was used to filter dichloromethane (DCM) from a simulated spacecraft gas stream. This adsorbent was tested as a possible commercial-off-the-shelf (COTS) filtration solution to controlling spacecraft air quality. DCM is a halocarbon commonly used in manufacturing for cleaning and degreasing and is a typical component of equipment offgassing in spacecraft. The performance of the filter was measured in dry and humid atmospheres. A known concentration of DCM was passed through the adsorbent at a known flow rate. The adsorbent removed dichloromethane until it reached the breakthrough volume. Carbosieve SIII exposed to dry atmospheric conditions adsorbed more DCM than when exposed to humid air. Carbosieve SIII is a useful thermally regenerated adsorbent for filtering DCM from spacecraft cabin air. However, in humid environments the gas passes through the filter sooner due to co-adsorption of additional water vapor from the atmosphere.

This work describes the microbiological assessment and materials compatibility of a silver-based biocide as an alternative to iodine for the Crew Exploration Vehicle (CEV) and future spacecraft potable water systems. In addition to physical and operational anti-microbial counter-measures, the prevention of microbial growth, biofilm formation, and microbiologically induced corrosion in water distribution and storage systems requires maintenance of a biologically-effective, residual biocide concentration in solution and on the wetted surfaces of the system. Because of the potential for biocide depletion in water distribution systems and the development of acquired biocide resistance within microbial populations, even sterile water with residual biocide may, over time, support the growth and/or proliferation of bacteria that pose a risk to crew health and environmental systems.

A lab-scale testbed for screening and characterizing the chemical specificity of commercial “off-the-shelf” (COTS) polymer adsorbents was built and tested. COTS polymer adsorbents are suitable candidates for future trace contaminant (TC) control technologies. Regenerable adsorbents could reduce overall TC control system mass and volume by minimizing the amounts of consumables to be resupplied and stored. However, the chemical specificity of these COTS adsorbents for non-methane volatile organic compounds (NMVOCs) (e.g., methanol, ethanol, dichloromethane, acetone, etc) commonly found in spacecraft is unknown. Furthermore, the effect of humidity on their filtering capacity is not well characterized. The testbed, composed of a humidifier, an incubator, and a gas generator, delivers NMVOC gas streams to conditioned sorbent tubes.

Advanced water processors being developed for NASA's Exploration Initiative rely on phase change technologies and/or biological processes as the primary means of water reclamation. As a result of the phase change, volatile compounds will also be transported into the distillate product stream. The catalytic reactor assembly used in the International Space Station (ISS) water processor assembly, referred to as Volatile Removal Assembly (VRA), has demonstrated high efficiency oxidation of many of these volatile contaminants, such as low molecular weight alcohols and acetic acid, and is considered a viable post treatment system for all advanced water processors. To support this investigation, two ersatz solutions were defined to be used for further evaluation of the VRA. The first solution was developed as part of an internal research and development project at Hamilton Sundstrand (HS), and is based primarily on ISS experience related to the development of the VRA.

Selecting the appropriate atmosphere for a spacecraft and mission is a complicated problem. NASA has previously used atmospheres from Earth normal composition and pressure to pure oxygen at low pressures. Future exploration missions will likely strike a compromise somewhere between the two, trying to balance operation impacts on EVA, safety concerns for flammability and health risks, life science and physiology questions, and other issues. Life support systems and internal thermal control systems are areas that will have to respond to changes in the atmospheric composition and pressure away from the Earth-like conditions currently used on the International Space Station. This paper examines life support and internal thermal control technologies currently in use or in development to find what impacts in design, efficiency and performance, or feasibility might be expected.

Under a NASA-sponsored technology development project, a multi-disciplinary team consisting of industry, academia, and government organizations lead by Hamilton Sundstrand is developing an amine-based humidity and CO2 removal process and prototype equipment for Vision for Space Exploration (VSE) applications. Originally this project sought to research enhanced amine formulations and incorporate a trace contaminant control capability into the sorbent. In October 2005, NASA re-directed the project team to accelerate the delivery of hardware by approximately one year and emphasize deployment on board the Crew Exploration Vehicle (CEV) as the near-term developmental goal. Preliminary performance requirements were defined based on nominal and off-nominal conditions and the design effort was initiated using the baseline amine sorbent, SA9T.

One of the most critical functions of ECLSS is to maintain the atmospheric oxygen concentration within habitable limits. On the ISS, this function is provided by the Major Constituent Analyzer (MCA). During ISS (International Space Station) crew increments 7 thru 9, the MCA was at risk of imminent failure as evident by sustained high ion-pump current levels. In the absence of continuous constituent measurement by the MCA, manual methods of estimating partial pressure of oxygen (ppO2) and concentration levels need to be developed and validated to: (1) ensure environmental control and life support, (2) prohibit ISS system and hardware damage, and (3) enable planned ISS activities that effect constituent balance.

This paper describes the current USL outfitting with design and development changes incorporated during the past year. The International Space Station (ISS) USL is outfitted with eleven systems racks, an optical quality nadir window for earth viewing experiments and accommodations for thirteen International Standard Payload Racks (ISPRs). International payloads utilize this outfitting in a “shirt sleeve” environment by sharing allocated system resources and flight crew time to perform long term microgravity experiments. Recent changes in Command and Data Handling, 120 Vdc power, liquid and air cooling, audio and video communication, space vacuum and microgravity systems resources are included. User interfaces, systems performance and environmental conditions, in addition to the ISS USL outfitting configuration, are also updated in this ICES paper.

This paper describes the current United States Laboratory (USL) outfitting following the transition from Space Station Freedom to International Space Station (ISS). The ISS USL is outfitted with eleven systems racks, an optical quality nadir window for earth viewing experiments and accommodations for thirteen International Standard Payload Racks (ISPRs). The international payloads utilize this outfitting in a “shirt sleeve” environment by sharing allocated system resources and flight crew time to perform long term microgravity experiments. These systems resources include Command and Data Handling, 120 Vdc power, liquid and air cooling, audio and video communication, space vacuum and location dependent levels of microgravity. The ISS USL outfitting configuration, user interfaces, systems performance and environmental conditions are included in this ICES paper.

Many changes have been approved for implementation into the International Space Station (ISS) design for Thermal Control (TC) since the System Design Review (SDR)conducted in March 1994. Some of the changes have resulted in changes in the basic content of the ISS TC Subsystem (TCS) while others have addressed more efficient ways of developing the system. The design changes were made to address several distinct facets of the program. Foremost was the intent to control costs of the ISS program. The intent to ensure that the ISS is not completely dependent on any one partner was a major reason for other changes. Refinement of the SDR design and identification and solution of problems with the SDR design resulted in other design changes. While the technology to be used for the ISS TC has remained the same during this period, significant changes have been made to the way the ISS thermal control technology is implemented.

NASA and the U.S. Army have designed, developed, and tested a Computer Aiding for Low-Altitude Helicopter Flight guidance system. This system provides guidance to the pilot for near-terrain covert helicopter operations. The guidance is presented to the pilot through symbology on a helmet mounted display. This system has demonstrated the feasibility of a pilot-centered concept of terrain flight guidance that preserves pilot flexibility and authority. The system was developed using extensive piloted simulation and then implemented in a UH-60 Blackhawk helicopter for flight development and evaluation. A close correlation between simulation and actual flight was found; however, in flight overall pilot workload increased and performance decreased. This paper presents a description of the basic system design, simulation, and flight evaluations.

Unlike a terrestrial electric utility which can purchase power from a neighboring utility, the Space Station Freedom (SSF) has strictly limited energy resources; as a result, source control, system monitoring, system protection and load management are essential to the safe and efficient operation of the SSF Electric Power System (EPS). These functions are being evaluated in the DC Power Management and Distribution (PMAD) Testbed which NASA LeRC has developed at the Power System Facility (PSF) located in Cleveland, Ohio. The testbed is an ideal platform to develop, integrate, and verify power system monitoring and control algorithms. State Estimation (SE) is a monitoring tool used extensively in terrestrial electric utilities to ensure safe power system operation.

Currently the U.S. is sponsoring production of radioisotope thermoelectric generators (RTGs) for the Cassini mission to Saturn; the SP-100 space nuclear reactor power system for NASA applications; a thermionic space reactor program for DoD applications as well as early work on nuclear propulsion. In an era of heightened public concern about having successful space ventures it is important that a full understanding be developed of what it means to “flight qualify” a space nuclear system. As a contribution to the ongoing work this paper reviews several qualification programs, including the general-purpose heat source radioisotope thermoelectric generators (GPHS-RTGs) as developed for the Galileo and Ulysses missions, the SNAP-10A space reactor, the Nuclear Engine for Rocket Vehicle Applications (NERVA), the F-1 chemical engine used on the Saturn-V, and the Space Shuttle Main Engines (SSMEs). Similarities and contrasts are noted.

For an optimum design, the weight, energy consumption, and operational flexibility of the traction drive system for a lunar roving vehicle must be considered along with the power supply, motor, and power train. Other problems considered in this paper include: environment and motor dissipation; motor type (a-c or d-c) and commutation if d-c; motor controller (switching of large currents); delivery of torque at varying speeds; the power train; use of regenerative braking and conservation of energy; and power supply voltage variation. These problems are studied in the light of certain general system specifications, which fall into weight, performance, and environment categories. Tradeoff studies are considered for purposes of optimization in each of these areas. Special consideration is given to the controller and system design as it pertains to regenerative braking and the conservation of energy.

The inability of available situation displays to provide a decelerating instrument approach capability to a hover led to a flight research program in which control-command information was displayed for three degrees of freedom. The test aircraft (NASA's CH-46C in-flight simulator) was stabilized with high-gain attitude command system. Using this system, the pilot was able to decelerate the aircraft to a hover while simultaneously following a 6 deg glidepath. Although these tests demonstrate the potential of this concept, a number of factors, including adequate integration of command and situation information, were identified as affecting pilot acceptance of the system.

The development from program inception of major Apollo spacecraft systems is reviewed. Those subsystems which required significant advances in current technology are highlighted, and important system development derived from Project Mercury and the Gemini Program is discussed where pertinent. The overall approach to satisfaction of mission requirements in the Apollo spacecraft is outlined in relation to the manned lunar landing. The paper illustrates that all mission-critical systems were designed with a high degree of reliability and redundancy because of the limited flight frequency, the denial of inflight maintenance, and the absence of an inflight rescue capability. For the lunar module, the first true spacecraft, significant unknowns that faced spacecraft designers could not be effectively resolved in any of the earth-orbit flight programs.

Large launch vehicle systems are examined in terms of design and operating characteristics and potential applications. A brief history of the development of Saturn V is followed by a discussion of potential cost-saving simplifications. Potentially attractive intermediate payload derivatives of Saturn V and the use of a nuclear third stage are considered along with potential missions. New concepts and technology discussed include low-cost expendable, partially reusable, and fully reusable systems in which the launch vehicle and spacecraft are integral. The need for, and desired characteristics of, a reusable “space shuttle” system are indicated and a brief description of alternate approaches to obtaining this system are presented.