Mechanical & Fluid Systems

Some improvements have been made to enhance the role of water as a test solvent for determining the amount of hydrocarbon nonvolatile residue (NVR) present on an item of hardware that is required to be totally or nearly devoid of such residue. Water is now used as an NVR-testing solvent...

A report discusses tests of finger seals, which were described in “Pressure- Balanced, Low-Hysteresis Finger Seal” (LEW-16840), which appears on page 52 in this issue. Like a labyrinth or brush seal, a finger seal is used (typically in a gas turbine) to minimize a leakage flow along a rotating shaft. The report describes...

The proposed Plant Harvesting Mechanization System (PHARMS) would comprise machinery and controls for semiautomated harvesting of plants grown in a controlled environment. The PHARMS was conceived as a prototype of harvesters to be incorporated into life-support systems of spacecraft and...

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...

A report presents a theoretical approach to designing a low-energy transfer of a spacecraft from an orbit around the Earth to ballistic capture into an orbit around the Moon. The approach is based partly on the one presented in “Low-Energy Interplanetary Transfers Using Lagrangian Points”...

A report discusses the continuing development of a normally closed, piezoelectrically actuated valve fabricated mostly by micromachining of silicon. The design and operation of the microvalve as described in the instant report are basically the same as those of the version described in...

A report proposes the development of a microfabricated, integrated colloid thruster as a prototype of devices for propulsion and control of the attitudes of microspacecraft. (In a colloid thruster, a beam of positively charged, microscopic droplets is extracted electrohydrodynamically from a column...

A report discusses algorithms for realtime planning of translation paths of multiple spacecraft flying in formation. The algorithm takes account of requirements to avoid collisions while operating within resource constraints (e.g., not calling for an acceleration greater than maximum possible) and...

A report proposes the development of a ground-based launch-assist apparatus that would accelerate a spacecraft to a speed of about 270 m/s. The apparatus would include a track along which the spacecraft would ride on a sled coupled to a large piston driven by compressed air along a tube (more...

An improved probe has been proposed for burrowing vertically into ice for scientific exploration of polar icecaps, glaciers, and the like. The predecessor of the improved probe is a Philbert probe, which contains an electric heater to melt the ice in contact with it and thereby make it descend...