Engineering topics

Baugher, Charles

Publications and source records attributed to Baugher, Charles.

4 records

NASA NTRS2001

Microgravity Science Glovebox

The Microgravity Science Glovebox (MSG) is a versatile research facility designed to permit the flexibility of crew manipulated investigations on the International Space Station (ISS). The MSG configuration has been planned around the concept of an experimental workstation where a variety of experiments can be installed and operated in a fashion very similar to their operation in a ground-based laboratory. The approach has been to provide a large working volume with a significant set of power, data and imaging resources, all enclosed, but accessible by the crew through sealed glove ports. This arrangement allows the advantage of interactive experimentation without unduly compromising the experiment design with restrictions imposed by protective and containment challenges that normally arise in manned space-flight laboratories. In addition, the data and imaging resources allow cooperative monitoring of experiment progress between the crew and ground-based scientists. As ISS utilization evolves, the MSG is scheduled to become a major pathfinder for developing and exploiting the scientific advantages of truly enabling the coupling of experimentation in space with an evaluative response from the crew and investigators.

Roark, Walt↗

NASA NTRS1998

Microgravity Science in Space Flight Gloveboxes

Microgravity science studies the influences of gravity on phenomena in fluids, materials processes, combustion, and human cell growth in the low acceleration environment of space flight. During the last decade, the accomplishment of the flight research in the field has evolved into an effective cooperation between the flight crew in the Shuttle and the ground-based investigator using real-time communication via voice and video links. This team structure has led to interactive operations in which the crew performs the experimentation while guided, as necessary, by the science investigator who formulated the investigation and who will subsequently interpret and analyze the data. One of the primary challenges to implementing this interactive research has been the necessity of structuring a means of handling fluids, gases, and hazardous materials in a manned laboratory that exhibits the novelty of weightlessness. Developing clever means of designing experiments in closed vessels is part of the solution- but the space flight requirement for one and two failure-tolerant containment systems leads to serious complications in the physical handling of sample materials. In response to the conflict between the clear advantage of human operation and judgment, versus the necessity to isolate the experiment from the crewmember and the spacecraft environment, the Microgravity Research Program has initiated a series of Gloveboxes in the various manned experiment carriers. These units provide a sealed containment vessel whose interior is under a negative pressure with respect to the ambient environment but is accessible to a crewmember through the glove ports.

Baugher, Charles↗

NASA NTRS1992

Analytical estimates of radial segregation in Bridgman growth from low-level steady and periodic accelerations

Approximate analytical solutions are developed that are mathematically tractable but provide the elements of CFD models for estimating convective flows subjected to low-level accelerations. The estimates are applicable to dilute systems that have horizontal temperature gradients in the vertical Bridgman configuration. The Navier-Stokes momentum equation is solved in 1D and subsequently in 2D by the first-order perturbation method. The analysis used is the case of plane-front solidification of a dilute system in the vertical thermally stable configuration. The model is found to predict the degree of radial segregation within a factor of two for a range of material and processing parameters. The method provides detailed information on the effects of processing on solute distribution in the grown crystal which are of interest in the orbital experiments emphasizing the control of radial segregation.

Naumann, Robert J.↗

NASA NTRS1992

Passive Accelerometer

Motion of ball in liquid indicates acceleration. Passive accelerometer measures small accelerations along cylindrical axis. Principle of operation based on Stokes' law. Provides accurate measurements of small quasi-steady accelerations. Additional advantage, automatically integrates out unwanted higher-frequency components of acceleration.

Naumann, Robert J.↗