Search Results

The docking and integration of the Priroda module into the Space Station Mir Complex in 1996 provided a unique opportunity to assess the potential impact on the trace contaminant concentrations in the station complex. Since Priroda was substantially loaded with new US flight hardware, the data are potentially relevant to future similar operations associated with the buildup of the International Space Station. Grab samples were collected to assess the Priroda concentrations prior to integration and to capture the profile of concentrations after the start of Priroda inter-module ventilation. A long term time integrated sampler was configured for collection of canister samples over a time interval of seven days.

The primary objectives of this study were to determine the factors that affect stability during locomotion in both lunar and martian gravity environments and to determine the criteria needed to enhance stability and traction. This study tested the effects of changing the speed of locomotion and the pattern of locomotion under three gravity conditions. The results showed that as the gravity level decreased, the amount of vertical and horizontal forces dropped significantly. The results also showed that there are some similarities across gravity levels with regard to changing the speed as well as the pattern of locomotion. In general, an increase in the speed resulted in an increase in the vertical and the horizontal forces. A change in the pattern of locomotion showed that even at reduced gravity, it will be more difficult to stop than compared to continue or start the motion.

Radio Technology Commission for Aeronautics (RTCA) at the request of the Federal Aviation Administration (FAA) formed a committee to prepare a Minimum Operating Performance Standard (MOPS) for aircraft batteries. The MOPS was limited to rechargeable and starting batteries as power sources for equipment installed in aircraft. This committee has being working for the last 3 years and completed the final draft during their 6th meeting in April 2004. The MOPS, to be used by the FAA as the base for a Technical Standard Order (TSO) in preparation, includes the testing and evaluation criteria required for secondary Lead-Acid (Pb-A) and Nickel-Cadmium (Ni-Cd) batteries airworthiness demonstration.

The need for Air Turbine Starter (ATS) condition monitoring is driven by industry demand for continuous improvement in reliability and reduction in repair and overhaul costs. This paper discusses issues for condition monitoring of Air Turbine Starters (ATS), including the need for condition monitoring, selection of monitoring parameters, current projects, and goals for future designs. The USAF is currently conducting a program to develop a simple, stand-alone device capable of indicating impending failures. This device will likely focus on a combination of temperature monitoring and magnetic chip detection. Future ATS condition monitoring devices should be capable of more comprehensive evaluation of starter parameters.

A noncontacting clearance seal consists of a series of centrifugal air pumps and oil/air separators for air turbine starters on the BR710 and the CFM56-5 engines. Conventional contacting seals for rotating shafts are limited in life due to the formation of oxidized oil coke buildup on the sealing surfaces. The clearance seal directly addresses the problem of viscous heat generation in carbon face and lip seals by eliminating contact. Standard contacting seals typically have local temperature increases of 50 to 75 °F higher than the gearbox sump oil. Heat generation by the clearance seal is minimized, resulting in a significant increase in reliability compared to a standard contacting seal. The reliability increase is estimated for various flight-hour-to-start-cycle ratios in air turbine starter gearboxes.