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Design Concepts for the ISS TransHab Module

Twelve reports present concepts for the design of structural and functional systems, subsystems, and components of the proposed TransHab module — an inflatable, lightweight habitation module that would be used by crewmembers of the International Space Station and would serve as a prototype of habitation modules for future spacecraft on long missions (e.g., missions to Mars). The TransHab module would be a unique hybrid structure that would combine the packaging and mass efficiencies of an inflatable structure with the advantages of a load-bearing hard structure. The governing design concept is one of a high degree of integration and multifunctionality of all parts of the Trans- Hab system. The reports include sketches (some containing estimated dimensions) and discussions of engineering requirements. There are also numerous discussions of human factors (psychological, social, and physiological) that affect many aspects of design. Although the reports address issues specific to the TransHab module, some of the concepts discussed may be applicable to the design of temporary or transportable housing for use on Earth.

Posted in: Mechanics, Briefs, TSP

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Inverted Hindle Mount Reduces Sag of a Large, Precise Mirror

The mirror is suspended from above by multiple, equally loaded supports. A mount has been devised to satisfy a requirement to suspend a highly precise, flat, circular, low-thermal-expansion glass mirror in a horizontal plane with its reflective side down while keeping the reflective mirror surface flat to within a peak-to-valley depth of less 50 nm. The difficulty of the suspension problem and the significance of the mount conceived as the solution of the problem arise from the large size and weight of the mirror (diameter 101.7 cm, thickness 18.8 cm, mass 385 kg).

Posted in: Mechanics, Briefs, TSP

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Heart-Pump-Outlet/Cannula Coupling

This coupling is separable, free of leaks, and configured to minimize clotting. A fluid coupling has been developed for use in securing a vascular outflow graft (cannula) to the outlet of a surgically implanted NASA/DeBakey heart assist pump. The design of the coupling can also be adapted to other applications in which it is necessary to join flexible tubes with rigid ones. A joint formed by use of this coupling is separable, yet free of leaks; this is advantageous in that (1) it is necessary to be able to install or remove a pump in accordance with requirements for surgery, sterilization, and pump maintenance, but (2) seepage of blood from an installed pump/cannula joint cannot be tolerated. Moreover, the coupling provides a smooth transition for flow from the pump outlet to the cannula; this feature helps to prevent clotting, which is triggered by flow-surface discontinuities.

Posted in: Mechanics, Briefs

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Surface-Launched Explorers for Reconnaissance/Scouting

Efficiency of robotic exploration would be increased. Small, instrumented, expendable robotic aircraft and projectiles have been proposed for use in scouting for targeted new sites by providing closeup images with ~10-cm resolution, covering large distances ~1 to 10 km quickly and allowing reconnaissance to enable sample return. Denoted microflyers or surface-launched explorers (SLEs), the proposed robotic aircraft and projectiles were conceived especially for use in the exploration of Mars and possibly other distant planets. SLEs could also be adapted to such terrestrial uses as military reconnaissance, exploration of hostile terrain (e.g., volcanoes, steep cliffs, or glaciers), surveying hazardous-waste sites, and searching for victims of earthquakes.

Posted in: Briefs, TSP

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Gear Bearings and Gear-Bearing Transmissions

Planetary transmissions could be simpler, cheaper, and more rigid. Gear bearings are conceptual mechanical components so named because they function as gears and as roller and/or thrust bearings. Gear bearings will be essential components of the next generation of compact, large-mechanical- advantage gear drives.

Posted in: Mechanics, Briefs, TSP

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Linear Dynamometer With Variable Stroke and Frequency

Stroke length and frequency can be adjusted continuously during operation. An improved linear dynamometer has been developed for testing linear alternators that are to be used to convert mechanical power to electrical power in free-piston Stirlingcycle engines. Both the frequency and the length of the stroke of this dynamometer can be varied continuously, even during operation; consequently, the dynamometer can be used to fully map the capabilities of a linear alternator throughout its service envelope (its operational range as defined on a plot of limiting stroke length versus frequency) in a single test.

Posted in: Briefs, TSP

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Study of Turbulent Boundary Layer on the F-15B Airplane

Automated hot-wire anemometry has been demonstrated in flight tests. NASA’s F-15B #836 is a two-seat version of the F-15, which is a high-performance, supersonic, all-weather fighter airplane. The F-15B is used as a test-bed aircraft for a wide variety of flight experiments. In support of this use, a flight-test fixture (FTF) was developed to provide a space for flight experiments in a region with known aerodynamic conditions. The FTF is a fully instrumented test article mounted on the center line of the bottom of the fuselage of an F-15B airplane. The FTF includes an interchangeable experiment panel and is 107 in. (2.72 m) long, 32 in. (0.81 m) high, and 8 in.(20.3 cm) wide, with a 12-in. (30.5-cm) elliptical nose section. The FTF has been used in many flight experiments during the past several years and can be modified to satisfy a variety of research requirements.

Posted in: Mechanics, Briefs, TSP

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