Keywords: orbital debris; space debris; aerogel; orbital debris collector; microscopes; spectroscopy
Abstract: The Mir Environmental Effects Package (MEEP) was deployed on the Mir station and retrieved after 18 months in space. The payload included the orbital debris collector (ODC), designed and built at the Johnson Space Center to capture and return analyzable residues of the manmade and natural particulate environment in low-Earth orbit for a detailed assessment of its compositional makeup and potential origins. The ODC exposed 2 identical trays, with highly porous, low-density Si02 aerogel as the basic collector medium, pointed in opposite directions. The aerogel was expected to gently decelerate and capture hypervelocity particles, as opposed to other media that resulted in melting or vaporization of many impactors. Even cursory examination of the returned ODC collectors revealed a surprising variety of impact features. The compositional analyses using scanning electron microscope-energy-dispersive X-ray spectroscopy concentrated on a survey-type inventory of diverse particle types and associated impact features. Detections, in the form of carrot-shaped tracks and shallow pits, included metallic Al, stainless steel, soldering compounds, human waste, and paint flakes. Many pits contained no detectable impactor residue (it was assumed to have vaporized), but most of the tracks contained analyzable residue. The study showed that aerogel would be useful for future low-velocity impact analysis.
Keywords: decompression sickness, decompression models, survival models, meta-analysis, rapid decompression, aircraft operations
Abstract: Estimating the risk of decompression sickness (DCS) in aircraft operations remains a challenge, making the reduction of this risk through the development of operationally acceptable denitrogenation schedules difficult. In addition, the medical recommendations which are promulgated are often not supported by rigorous evaluation of the available data, but are instead arrived at by negotiation with the aircraft operations community, are adapted from other similar aircraft operations, or are based upon the opinion of the local medical community. We present a systematic approach for defining DCS risk in aircraft operations by analyzing the data available for a specific aircraft, flight profile, and aviator population. Once the risk of DCS in a particular aircraft operation is known, appropriate steps can be taken to reduce this risk to a level acceptable to the applicable aviation community. Using this technique will allow any aviation medical community to arrive at the best estimate of DCS risk for its specific mission and aviator population and will allow systematic reevaluation of the decision regarding DCS risk reduction when additional data are available.
Keywords: seats; levers; spacecraft equipment; spacecraft cabins; spacecraft structures; backrests; resistance; pulling
Abstract: In 1999, a Shuttle crewmember was unable to operate the backrest lever for the lightweight seat in microgravity. It's essential that crewmembers can adjust this backrest lever, which is tilted forward during launch and then moved backward upon reaching orbit. This adjustment's needed to cushion the crew during an inadvertent crash landing situation. JSC's Anthropometric and Biomechanics Facility evaluated the seat controls and provided recommendations on whether the seat lever positions and operations should be modified.The original Shuttle seats were replaced with new lightweight seats whose controls were moved. They designed a 12-person experiment to investigate the amount of pull force exerted by suited subjects, when controls were placed in the front and back of the lightweight seat. Subjects performed the pull test. The results showed that, in general, the subjects were able to pull on the lever at the back position with only about half the amount of force they exerted on the front lever. Also, the subjects wearing pressurized suits were unable to reach the lever when located at the back, and the pull forces diminished about 50% when they wore the pressurized suits. We recommended that levers not be located in the back and that we need further investigation to see whether the front lever could be ajusted to increase the leverage for crewmembers wearing the pressurized suit.
Keywords: space shuttle missions; Mir Space Station; astronaut performance; astronauts;
Abstract: This report consists of inputs from each of the Phase 1 Program Joint Working Groups. The Working Groups were tasked to describe the organizational structure and work processes that they used during the program, joint accomplishments, lessons learned, and applications to the International Space Station Program. This report is a top-level joint reference document that contains information of interest to both countries.
Keywords: space debris, environmental effects, reentry effects, collision rates, debris, orbit decay, histories, bibliographies
Abstract: This chronology covers the 37-year history of orbital debris concerns. It tracks orbital debris hazard creation, research, observation, experimentation, management, mitigation, protection, and policy. Included are debris-producing events; UN orbital debris treaties; Space Shuttle and space station orbital debris issues; ASAT tests; milestones in theory and modeling; uncontrolled reentries; detection system development; shielding development; geosynchronous debris issues, including reboost policies; returned surfaces studies; seminal papers, reports, conferences, and studies; the increasing effect of space activities on astronomy; and growing international awareness of the near-Earth environment.
Keywords: Mir Space Station, Spacecraft Docking, Space Stations, Spacecraft Configurations
Abstract: Dockings, module additions, configuration changes, crew changes, and major mission events are tracked for Mir missions 17 through 21 (November 1994 through August 1996). The international aspects of these missions are presented, comprising joint missions with ESA and NASA, including three U.S. Space Shuttle dockings. New Mir modules described are Spektr, the Docking Module, and Priroda.
Keywords: spectrometers, cosmic rays, antimatter, International Space Station, observatories, calorimeters, accelorators, extraterrestrial radiation
Abstract: In 1994 the NASA Administrator selected the first high-energy particle physics experiment for the International Space Station (ISS), the alpha magnetic spectrometer (AMS), to place a magnetic spectrometer in Earth orbit and search for cosmic antimatter. A natural consequence of this decision was that NASA would begin to explore cost-effective ways through which the design and implementation of AMS might benefit other promising payload experiments. The first such experiment to come forward was Advanced Cosmic-Ray Composition Experiment for Space Station (ACCESS) in 1996. It was proposed as a new mission concept in space physics to attach a cosmic-ray experiment of weight, volume, and geometry similar to the AMS on the ISS, and replace the latter as its successor when the AMS is returned to Earth. This was to be an extension of NASA's suborbital balloon program, with balloon payloads serving as the precursor flights and heritage for ACCESS. The balloon programs have always been a cost-effective NASA resource since the particle physics instrumentation for balloon and space applications are directly related. The next step was to expand the process, pooling together expertise from various NASA centers and universities while opening up definition of the ACCESS science goals to the international community through the standard practice of peer review. This process is still ongoing, and the accommodation study presented here will discuss the baseline definition of ACCESS as we understand it today.
Keywords: manned space flight; space stations; Mercury; Gemini; Apollo; Skylab; Mir
Abstract: Biomedical issues have presented a challenge to flight physicians, scientists, and engineers ever since the advent of high-speed, high-altitude airplane flight in the 1940s. In 1958, preparations began for the first manned space flights of Project Mercury. The medical data and flight experience gained through Mercury's six flights, the Gemini, Apollo, and Skylab projects, as well as subsequent space flights comprised the knowledge base which was used to develop and implement the Extended Duration Orbiter Medical Project (EDOMP). In addition, a significant amount of hardware was developed and tested under the EDOMP which was designed to improve data gathering capabilities and maintain crew physical fitness while minimizing the overall impact to the microgravity environment. The biomedical findings as well as the hardware development results realized from the EDOMP have been important to the continuing success of extended Space Shuttle flights and have formed the basis for medical studies of crewmembers living for three to five months aboard the Russian space station, Mir. EDOMP data and hardware are also being used in preparation for the construction and habitation of International Space Station.
Keywords: airports, air defense, military aircraft, aircraft design, aircraft pilots, airport planning, armed forces (United States)
Abstract: This document details the chronological history of an air field in Southeast Texas that currently serves as an adjunct to NASA Johnson Space Center as well as a civilian/military air field. The field was built early in the 20th century, soon after airplane flight became a recognized factor in American military applications, was central to a wide variety of military uses throughout this century, and remains viable for such purposes in addition to serving a vital role in NASA's training of astronauts.
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