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An advanced development helmet mounted display (HMD) was designed and fabricated under NASA-Johnson Space Center (NASA/JSC) contract, NAS 9-17543, by Hamilton Standard Division of United Technologies, Windsor Locks, CT. The work was initiated in December 1985 and culminated in June 1988 with the delivery of an extravehicular mobility unit (EMU) HMD demonstration unit as an alternative to the current low-resolution, chest-mounted display and cuff-mounted checklists. Important design goals achieved with this HMD include the use of transmissive liquid crystal display (LCD) image sources with fairly high resolution (i.e., text, graphics, and video compatible), binocular viewing with total image overlap, virtual image projection, low profile packaging, low power design, and demonstration of voice control of the HMD data.

The electro-thermal method is most commonly used for wind turbine anti-/de-icing. The upmost drawback of such systems is the high power consumption. In the present study, we proposed to use a durable slippery liquid-infused porous surface (SLIPS) to effectively reduce the power requirement of the heating element during the anti-/de-icing process. The explorative study was conducted in the Icing Research Tunnel at Iowa State University (ISU-IRT) with a DU91-W2-250 wind turbine blade model exposed under severe icing conditions. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion process, an infrared (IR) thermal imaging system was also utilized to achieve the simultaneous surface temperature measurements over the test model.

Wind turbine icing represents the most significant threat to the integrity of wind turbines in cold weather. Ice formation on wind turbine blades was found to cause significant aerodynamic performance degradation, resulting in a substantial drop in energy production. Recently developed Dielectric barrier discharge (DBD) plasma-based anti-/de-icing systems showed very promising effects for aircraft icing mitigation. In this present study, DBD plasma-based anti-/de-icing systems were employed for wind turbine icing mitigation. First, a comprehensive parametric study is conducted to investigate the effects of various DBD plasma actuation parameters on its thermodynamic characteristics. An infrared (IR) thermal imaging system is used to quantitatively measure the temperature distributions over the test plate under various test conditions.

NASA issued a Request For Information (RFI) to identify technologies that might be available to monitor a list of air pollutants in the ISS atmosphere. After NASA received responses to the RFI, an expert panel was assembled to hear presentations from 9 technology proponents. The goal of the panel was to identify technologies that might be suitable for replacement of the current Volatile Organics Analyzer (VOA) within several years. The panelists consisted of 8 experts in analytical chemistry without any links to NASA and 7 people with specific expertise because of their roles in NASA programs. Each technology was scored using a tool that enabled rating of many specific aspects of the technology on a 4-point system. The maturity of the technologies ranged from well-tested instrument packages that had been designed for space applications and were nearly ready for flight to technologies that were untested and speculative in nature.

Most of the studies conducted on the design of inflated fabric structures for space applications have focused on types of yarns and coating selection. The design of seams along with materials selection considerations is also crucial to the design of inflatable structures. This paper presents a pilot study of the modes of failure for fabrics with two selected sewn seams under biaxial stress loading. A literature review of sewn seam testing techniques reveals that conventional methods do not accurately simulate the biaxial stresses to which inflated fabrics are subjected. In this study, biaxial stresses are obtained by using a cylindrical pressure testing apparatus developed originally for testing seam design for an inflatable Lunar habitat. The unique features of the test method for sewn seams of fabrics by cylindrical pressure loading are described. Test data is presented, and the sensitivity of the test to changes is also discussed.

Airborne dust, suspended inside a space vehicle or in future celestial habitats, can present a serious threat to crew health if it is not controlled. During some Apollo missions to the moon, lunar dust brought inside the capsule caused eye irritation and breathing difficulty to the crew when they launched from the moon and reacquired “microgravity.” During Shuttle flights reactive and toxic dusts such as lithium hydroxide have created a risk to crew health, and fine particles from combustion events can be especially worrisome. Under nominal spaceflight conditions, airborne dusts and particles tend to be larger than on earth because of the absence of gravity settling. Aboard the ISS, dusts are effectively managed by high efficiency filters, although floating dust in newly-arrived modules can be a nuisance.

The promising anti-icing performance of the slippery liquid infused porous surface (SLIPS) has been recently demonstrated for various engineering applications. The runback icing for aircraft and wind turbines could be effectively mitigated considering the timely removal of water droplet by the wind shearing force due to the low adhesion on the SLIPS. In this study, the flow field both inside and around the wind-driven droplet over the SLIPS was experimentally investigated by using Particle Image Velocimetry (PIV) technique. Previous studies majorly focus on the internal flow pattern before the droplet incipient motion. In this study, the flow field inside a moving droplet was firstly investigated. As a result of the low surface adhesion of the SLIPS, droplet oscillations were eliminated and the droplet internal flow field could be corrected from the optical distortion.

Atmospheric icing poses a major threat to power transmission lines in cold regions. In the present study, an experimental investigation was conducted to examine the atmospheric icing process on high-voltage power transmission lines and characterize the effects of the ice accretion on the aerodynamic forces acting on the transmission lines. The experimental study was conducted in the Icing Research Tunnel available at Iowa State University (ISU-IRT). A cylinder model with the same diameter of commonly-used high-voltage power transmission lines (i.e., D = 29mm) is subjected to a typical glaze icing condition at an incoming wind speed of 20 m/s, a liquid water content (LWC) of 2.0 g/m3 and an ambient temperature of -5 0C. A high-resolution 3D scanner was used in the present study to extract the 3D shapes of the ice structures accreted over surface of the cylindrical test model as a function of the ice accretion time.

In the present study, an experimental investigation was conducted to characterize a hot-air-based anti-/de-icing system for the icing protection of aero-engine inlet guide vanes(IGVs). The experimental study was conducted in a unique icing research tunnel available at Iowa State University (i.e., ISU-IRT). A hollowed IGV model embedded with U-shaped hot-air flowing conduit was designed and manufactured for the experimental investigations. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion or anti-/de-icing process over the surface of the IGV model for the test cases without and with the hot-air supply system being turned on, the corresponding surface temperature distributions on the IGV model were measured quantitatively by using a row of embedded thermocouples.

An experimental study was conducted to investigate the dynamic ice accretion processes on bridge cables with different surface modifications (i.e., 1. Standard plain, 2. Pattern-indented surface, and 3. helical fillets). The icing experiments were performed in the unique Icing Research Tunnel available at Iowa State University (i.e., ISU-IRT). In order to reveal the transient ice accretion processes and the associated aerodynamic loadings on the different cable models under the different icing conditions (i.e., rime vs. glaze), while a high-speed imaging system was used to capture the transient details of the surface water transport and ice accretion over the cable surfaces, a high-accuracy dual-transducer force measurement system was also utilized to measure the aerodynamic loadings acting on the ice accreting cable models.

Recently developed dielectric barrier discharge (DBD) plasma-based anti-icing systems have shown great potential for aircraft icing mitigation. In the present study, the ice accretion experiments were performed on to evaluate the effects of different layouts of DBD plasma actuators on their anti-/de-icing performances for aircraft icing mitigations. An array of DBD plasma actuators were designed and embedded on the surface of a NACA0012 airfoil/wing model in different layout configurations (i.e., different alignment directions of the plasm actuators (e.g., spanwise vs. streamwise), width of the exposed electrodes and the gap between the electrodes) for the experimental study. The experimental study was carried out in the Icing Research Tunnel available at Iowa State University (i.e., ISUIRT).

Ice accretion on aero-engines, especially on the fan blades, is the very hazardous icing incident due to the potential performance degradation of jet-engines. In the present study, an experimental investigation was conducted to examine the performance of ice-phobic coatings for jet-engine fan icing mitigation. The experimental study was performed in the unique Icing Research Tunnel at Iowa State University (ISU-IRT) with a scaled engine fan model operated under wet glaze and dry rime ice conditions. To evaluate the effects of anti-icing coatings and to acquire the important details of ice accretion and shedding process on fan blade surfaces, a “phase-locked” imaging technique was applied with a high-resolution imaging system. The power input required to drive the engine fan model rotating at a constant prescribed speed was also measured during the ice accretion experiment.

Elastic soft material/surface, such as Polydimethylsiloxane (PDMS), is a perspective, useful and low-cost hydrophobic and icephobic coating. While it has been reported to have good mechanical durability, its erosion durability under the high impacting of water droplets pertinent to aircraft inflight icing phenomena has not been explored. In this study, the droplet imping erosion characteristics of an icephobic PDMS surface/material is evaluated systematically upon the dynamic impinging of water droplets at different impact velocities (~ up to 75m/s), in comparison with other state-of-the-art icephobic materials/surfaces, such as superhydrophobic surface (SHS) and slippery liquid-infused porous surface (SLIPS). Surprisingly, the contact angle (CA) of the elastic PDMS is shown to have an over 20° increase (from 105° to 128°), which represents better hydrophobicity, after the erosion test which is mainly contributed to the higher roughness of the eroded PDMS surface.

An explorative study was performed to demonstrate the feasibility of using a novel hybrid anti-/de-icing strategy for aircraft icing mitigation. The hybrid method was developed by combining the electro-thermal heating mechanism and specialized surfaces/coatings with different wettabilities. While an electrical film heater was utilized to provide thermal energy around the leading edge of a NACA0012 airfoil model, two different coating strategies, (i.e., (a). Superhydrophobic coating covering the entire airfoil surface to increase droplets bounce-off and accelerate surface water runback vs. (b). super-hydrophilic coating at the leading edge to increase evaporation area + superhydrophobic coating in downstream to prevent runback refreezing) were proposed and evaluated aiming at maximizing the anti-/de-icing efficiency of the hybrid method.

Typical calculations of radiation exposures in space approximate the composition of the human body by a single material, typically Aluminum or water. A further approximation is made with regard to body size by using a single anatomical model to represent people of all sizes. A comparison of calculations of organ dose and dose-equivalent is presented. Calculations are first performed approximating body materials by water equivalent thickness', and then using a more accurate representation of materials present in the body. In each case of material representation, a further comparison is presented of calculations performed modeling people of different sizes.

Airborne, marine and ground structures are vulnerable to atmospheric icing in cold weather operation conditions. Most of the ice adhesion-related work have focused on the mechanical ice removal strategies because of practical considerations, while limited literature is available for fundamental understanding of the ice adhesion process. Here, we present a fracture mechanics-based approach to characterize interfacial fracture parameters for the shear behavior of a typical ice/aluminum interface. An experimental framework employing two complementary tests (1) lap shear and (2) shear push-out tests was introduced to assess the mode-II fracture parameters for the selected aluminum/ice interface. Both analytical (shear-lag analysis) and numerical (finite element analysis incorporating cohesive zone method) models were used to evaluate shear fracture parameters.

At present, spacecraft water quality is assessed when samples collected on the International Space Station (ISS) are returned to Earth. Several months, however, may pass between sample collection and analysis, potentially compromising sample integrity by risking degradation. For example, iodine and silver, which are the respective biocides used in the U.S. and Russian spacecraft potable water systems, must be held at levels that prevent bacterial growth, while avoiding adverse effects on crew health. A comparable need exists for the detection of many heavy metals, toxic organic compounds, and microorganisms. Lead, cadmium, and nickel have been found, for instance, in the ISS potable water system at amounts that surpass existent requirements. There have been similar occurrences with hazardous organic compounds like formaldehyde and ethylene glycol. Microorganism counts above acceptable limits have also been reported in a few instances.

Colorimetric-solid phase extraction (C-SPE) is being developed as a method for in-flight monitoring of spacecraft water quality. C-SPE is based on measuring the change in the diffuse reflectance spectrum of indicator disks following exposure to a water sample. Previous microgravity testing has shown that air bubbles suspended in water samples can cause uncertainty in the volume of liquid passed through the disks, leading to errors in the determination of water quality parameter concentrations. We report here the results of a recent series of C-9 microgravity experiments designed to evaluate manual manipulation as a means to collect bubble-free water samples of specified volumes from water sample bags containing up to 47% air. The effectiveness of manual manipulation was verified by comparing the results from C-SPE analyses of silver(I) and iodine performed in-flight using samples collected and debubbled in microgravity to those performed on-ground using bubble-free samples.

A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks.

The Crew Exploration Vehicle (CEV) is the first crew transport vehicle to be developed by the National Aeronautics and Space Administration (NASA) in the last thirty years. The CEV is being developed to transport the crew safely from the Earth to the International Space Station and then later, from the Earth to the Moon . This year, the vehicle continued to go through design refinements to reduce weight, meet requirements, and operate reliably while preparing for Preliminary Design Review in the summer of 2009. The design of the Orion Environmental Control and Life Support (ECLS) system, which includes the life support and active thermal control systems, is progressing through the design stage. This paper covers the Orion ECLS development from April 2008 to April 2009.