Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “KC”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Zero-Gravity Vortex Vent and PVT Gaging System

Space Station and satellite reservicing will require the ability to vent gas on orbit from liquid supply or storage tanks and to gage liquid quantity under microgravity conditions. In zero gravity, (zero-g) the vortex vent is capable of venting gas from a tank of liquid containing gas randomly distributed as bubbles. The concept uses a spinning impeller to create centrifugal force inside a vortex tube within a tank. This creates a gas pocket and forces the liquid through a venturi and back into the tank. Gas is then vented from the gas pocket through a liquid detector and then out through an exhaust port. If the liquid detector senses liquid in the vent line, the fluid is directed to the low-pressure port on the venturi and is returned to the tank. The advantages of this system is that it has no rotating seals and is compatible with most corrosive and cryogenic fluids. A prototype was designed and built at the NASA Johnson Space Center and flown on the KC-135 zero-g aircraft. During these test flights, where microgravity conditions are obtained for up to 30 sec, the prototype demonstrated that less than 0.10 percent of the volume of fluid vented was liquid when the tank was half full of liquid. The pressure volume temperature (PVT) gaging system is used in conjunction with the vortex vent to calculate the amount of liquid remaining in a tank under microgravity conditions. The PVT gaging system is used in conjunction with the vortex vent to gage liquid quantity in zero or low gravity. The system consists of a gas compressor, accumulator, and temperature and pressure instrumentation. To measure the liquid in a tank a small amount of gas is vented from the tank to the compressor and compressed into the accumulator. Pressure and temperature in the tank and accumulator are measured before and after the gas transfer occurs. Knowing the total volume of the tank, the volume of the accumulator, the volume of the intermediate lines, and initial and final pressures and temperatures, the mass of the gas leaving the tank is equated to the mass of the gas entering the accumulator. The volume of liquid remaining in the tank is calculated using the ideal gas law.

Downey, M. G.↗
NASA NTRS1990

Vibration responses of two house structures during the Edwards Air Force Base phase of the national sonic boom program

The data are reproduced from NSBEO-1-67, which contains some preliminary results of the test program, and from NASA-Langley working papers 259 and 288 which are now out of print. Included are sample acceleration and strain recordings from F-104, B-58, and XB-70 sonic boom exposures, along with tabulations of the maximum acceleration and strain values measured for each one of about 130 flight tests. These data are compared with similar measurements for engine noise exposures of the building during simulated landing approaches and takeoffs of KC-135 aircraft.

Hubbard, Harvey H.↗
NASA NTRS1989

Influence of non steady gravity on natural convection during micro-gravity solidification of semiconductors. I - Time scale analysis. II - Implications for crystal growth experiments

Consideration is given to the influence of temporal variations in the magnitude of gravity on natural convection during unidirectional solidification of semiconductors. It is shown that the response time to step changes in g at low Rayleigh numbers is controlled by the momentum diffusive time scale. At higher Rayleigh numbers, the response time to increases in g is reduced because of inertial effects. The degree of perturbation of flow fields by transients in the gravitational acceleration on the Space Shuttle and the Space Station is determined. The analysis is used to derive the requirements for crystal growth experiments conducted on low duration low-g vehicles. Also, the effectiveness of sounding rockets and KC-135 aircraft for microgravity experiments is examined.

Griffin, P. R.↗
NASA NTRS1989

Human factors and productivity on Space Station Freedom

Three main facets of man systems are investigated with reference to the Space Station Freedom program: specific hardware systems that focus on the human element; requirements definition for man-systems integration; and crew interface and operations analysis. Three key criteria have been identified for selecting individuals to constitute the human system or crew for Space Station Freedom missions: aptitude for mission specific skills, motivation, and sensitivity to self and others. Integration of the human system into the complex engineering and science systems planned on Space Station Freedom will require the close collaboration of engineers, physicians, psychologists, and human factors experts. Ground-based research and experiments on the KC-135 aircraft are providing information about how human systems will function on a space station and how to design other systems to interact with the crew. A laboratory for further research will be provided onboard Space Station Freedom.

Leach, C. S.↗
NASA NTRS1990

Ground based studies of the vibrational and rotational dynamics of acoustically levitated drops and shells

A substantial amount of experimental data can be gathered on the dynamics of acoustically positioned liquids in a ground-based laboratory and during short duration low-gravity parabolic flights of the KC-135. The preliminary results of a set of measurements of the static shape, of the vibrational spectrum, and the rotation equilibrium shapes of simple drops and liquid shells carried out using ultrasonic levitators working between 19 and 40 kHz is presented. The droplet diameter ranges between 1 and 5 mm, the surface tension of the liquid used varies between 25 and 70 dynes/cm, and the viscosity is changed between 1 to 1,000 cP. Of particular interest is the variation of the frequency of the fundamental mode of shape oscillation with various factors, and the effects of static drop shape deformation on the limit of stability of the axisymmetric shape of a drop in solid-body rotation.

Trinh, E. H.↗
NASA NTRS1989

Performance evaluation of advanced space suit concepts for Space Station

The requirements for an advanced space suit for Space Station EVA and the methods used to evaluate candidate suit concepts are examined. Two candidate Space Station suits, the AX-5 and the Mk. III, are described and illustrated. The methods to test these suits are discussed, including, tests at the NASA/Johnson Space Center Weightless Environment Training Facility, tests in the microgravity environment of the KC-135 aircraft, CO2 washout evaluations, component torque measurements, environmental hazards protection evaluations, and component cycle life verification.

Klaus, David M.↗
NASA NTRS1990

Binding of alpha-fetoprotein by immobilized monoclonal antibodies during episodes of zero-gravity obtained by parabolic flight

Alpha-fetoprotein (AFP), a single-chain polypeptide which is synthesized by the liver and yolk sac of the human fetus, provided a model ligand for assessing the effects of microgravity on ligand binding to surface-immobilized model receptor molecules. Monoclonal antibodies, used as receptors for AFP, were immobilized by covalent attachment to latex microparticles. Zero gravity environment was obtained by parabolic flight aboard NASA 930, a modified KC-135 aircraft. Buring the onset of an episode of zero gravity, ligand and receptor were mixed. Timed incubation (20 s) was terminated by centrifugation, the supernatant removed, and microparticies were assessed for bound AFP by immunochemical methods. The extent of binding was not influenced by microgravity, when compared with 1-G controls, which suggests that aberrant cellular activities observed in microgravity are not the simple expression of altered macromolecular interactions.

Spooner, Brian S.↗
NASA NTRS1990

A gravitational test of wave reinforcement versus fluid density models

Spermatozoa, protozoa, and algae form macroscopic patterns somewhat analogous to thermally driven convection cells. These bioconvective patterns have attracted interest in the fluid dynamics community, but whether in all cases these waves were gravity driven was unknown. There are two conflicting theories, one gravity dependent (fluid density model), the other gravity independent (wave reinforcement theory). The primary objectives of the summer faculty fellows were to: (1) assist in sample collection (spermatozoa) and preparation for the KC-135 research airplane experiment; and (2) to collaborate on ground testing of bioconvective variables such as motility, concentration, morphology, etc., in relation to their macroscopic patterns. Results are very briefly given.

Johnson, Jacqueline Umstead↗
NASA NTRS1991

Microgravity cursor control device evaluation for Space Station Freedom workstations

This research addressed direct manipulation interface (curser-controlled device) usability in microgravity. The data discussed are from KC-135 flights. This included pointing and dragging movements over a variety of angles and distances. Detailed error and completion time data provided researchers with information regarding cursor control shape, selection button arrangement, sensitivity, selection modes, and considerations for future research.

Adam, Susan↗
NASA NTRS1990

A dynamic technique for measuring surface tension at high temperatures in microgravity environment

The feasibility of a dynamic technique for measuring surface tension of liquid metals at high temperatures in a microgravity environment was demonstrated. The basic method involves heating a tubular specimen resistively from ambient temperature through its melting point in about 1 sec by passing an electrical current pulse through it, while simultaneously recording the pertinent experimental quantities. Static equilibrium for the molten specimen is achieved in a microgravity environment by splitting the current after it passes through the specimen tube and returning a fraction along the tube axis, and the remaining fraction outside the specimen. Adjustments to the current split enable a balance between the magnetic and surface tension forces acting on the specimen. Values for surface tension are determined from measurements of the equilibrium dimensions of the molten specimen tube, and the magnitudes of the currents. Rapid melting experiments, performed during microgravity simulations with the NASA KC-135 aircraft, yield a value for the surface tension of copper at its melting point which is in agreement with literature data. Measurements of surface tension of a refractory metal (tantalum) are underway.

Miiller, A. P.↗
NASA NTRS1990

Some considerations for various positioning systems and their science capabilities

Containerless processing of materials at elevated temperatures is discussed with emphasis on high temperature chemistry, thermophysical properties, materials science, and materials processing. Acoustic and electromagnetic positioning of high temperature melts are discussed. Results from recent ground based experiments, including KC-135 testing of an acoustic levitator, are presented. Some current positioning technologies and the potential for enhancing them are considered. Further, a summary of these technologies and their science capabilities for the development of future experiments is given.

Rey, Charles A.↗
NASA NTRS1991

Influence of a magnetic field during directional solidification of MAR-M 246 + Hf superalloy

An area that has been almost totally overlooked in the optimization of properties in directionally solidified superalloys is the control of microstructural features through the application of a magnetic field during solidification. The influence of a magnetic field on the microstructural features of a nickel-base superalloys is investigated. Studies were performed on the dendritic MAR-M 246+Hf alloy, which was solidified under both a 5 K gauss magnetic field and under no-applied-field conditions. The possible influences of the magnetic field on the solidification process were observed by studying variations in microstructural features including volume fraction, surface area, number, and shape of the carbide particles. Stereological factors analyzed also included primary and secondary dendrite arm spacing and the volume fraction of the interdendritic eutectic constituent. Microprobe analysis was performed to determine the chemistry of the carbides, dendrites, and interdendritic constituents, and how it varied between field and no-field solidification samples. Experiments involving periodic application and removal of the magnetic field were also performed in order to permit a comparison with structural variations observed in a MAR-M 246+Hf alloy solidified during KC-135 high-g, low-g maneuvers.

Andrews, J. Barry↗
NASA NTRS1991

Mini-rack testbed evaluation

The goal was to characterize the Health Maintenance Facility (HMF)-like mini-racks and drawers onboard the KC-135 as a test bed for the Space Station Freedom HMF racks. An additional goal was to evaluate the attachments, mounting points, and inner drawer assemblies of the mini-racks for various medical equipment and supplies. Results and recommendations are given.

Gosbee, John↗
NASA NTRS1991

Application and use of spinal immobilization devices in zero-gravity flight

A KC-135 parabolic flight was performed for the purpose of evaluation of spinal immobilization techniques in microgravity. The flight followed the standard 40 parabola profile with four NASA/KRUG experimenters involved. One performed as coordinator/recorder, one as test subject, and two as the Crew Medical Officers (CMO). The flight was to evaluate the application of spinal immobilization devices and techniques in microgravity as are performed during initial stabilization or patient transport scenarios. The sequence of detail for examination of the following objectives included: attempted cervical spine immobilization with all free floating, the patient restrained to the floor, various hand positioning techniques; c-collar placement; Kendrick Extrication Device (KED) application with various restraints for patient and CMO; patient immobilization and transport using the KED; patient transported on KED and spine board. Observations for each task are included. Major conclusions and issues are also included.

Krupa, Debra T.↗
NASA NTRS1991

ATLS-stowage and deployment testing of medical supplies and pharmaceuticals

The objective is to evaluate stowage and deployment methods for the Health Maintenance Facility (HMF) during microgravity. The specific objectives of this experiment are: (1) to evaluate the stowage and deployment mechanisms for the medical supplies; and (2) to evaluate the procedures for performing medical scenarios. To accomplish these objectives, the HMF test mini-racks will contain medical equipment mounted in the racks; and self-contained drawers with various mechanisms for stowing and deploying items. The medical supplies and pharmaceuticals will be destowed, handled, and restowed. The in-flight test procedures and other aspects of the KC-135 parabolic flight test to simulate weightlessness are presented.

Gosbee, John↗
NASA NTRS1991

Minor surgery in microgravity

The purpose is to investigate and demonstrate equipment and techniques proposed for minor surgery on Space Station Freedom (SSF). The objectives are: (1) to test and evaluate methods of surgical instrument packaging and deployment; (2) to test and evaluate methods of surgical site preparation and draping; (3) to evaluate techniques of sterile procedure and maintaining sterile field; (4) to evaluate methods of trash management during medical/surgical procedures; and (4) to gain experience in techniques for performing surgery in microgravity. A KC-135 parabolic flight test was performed on March 30, 1990 with the goal of investigating and demonstrating surgical equipment and techniques under consideration for use on SSF. The flight followed the standard 40 parabola profile with 20 to 25 seconds of near-zero gravity in each parabola.

Billica, Roger↗
NASA NTRS1991

Evaluation of prototype Advanced Life Support (ALS) pack for use by the Health Maintenance Facility (HMF) on Space Station Freedom (SSF)

The purpose is to evaluate the prototype Advanced Life Support (ALS) Pack which was developed for the Health Maintenance Facility (HMF). This pack will enable the Crew Medical Officer (CMO) to have ready access to advanced life support supplies and equipment for time critical responses to any situation within the Space Station Freedom. The objectives are: (1) to evaluate the design of the pack; and (2) to collect comments for revision to the design of the pack. The in-flight test procedures and other aspects of the KC-135 parabolic test flight to simulate weightlessness are presented.

Krupa, Debra T.↗
NASA NTRS1991

Venipuncture and intravenous infusion access during zero-gravity flight

The purpose of this experiment is to establish the difficulty associated with securing an intravenous (IV) catheter in place in microgravity flight and the techniques applicable in training the Crew Medical Officer (CMO) for Space Station Freedom, as well as aiding in the selection of appropriate hardware and supplies for the Health Maintenance Facility (HMF). The objectives are the following: (1) to determine the difficulties associated with venipuncture in a microgravity environment; (2) to evaluate the various methods of securing an IV catheter and attached tubing for infusion with regard to the unique environment; (3) to evaluate the various materials available for securing an intravenous catheter in place; and (4) to evaluate the fluid therapy administration system when functioning in a complete system. The inflight test procedures and other aspects of the KC-135 parabolic flight test to simulate microgravity are presented.

Krupa, Debra T.↗