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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

High-temperature containerless aircraft furnace experimentation in the microgravity environment aboard a KC-135 aircraft

This paper describes a materials processing research furnace, the High-Temperature Containerless Aircraft Furnace (HITCAF), which uses an electric arc to melt and resolidify materials in the microgravity environment aboard a KC-135 aircraft. The HITCAF is designed to process almost every electrically conductive material, including such high-melting-point materials as tungsten, within a 15 to 20 sec microgravity period. It operates on tungsten/inert gas welding principles, using an adapted commercially available tube welder. The HITCAF is fully operational and available for use by researchers representing the Government agencies, as well as industry and academia.

Poorman, Richard M.↗
NASA NTRS1989

Mixed gravity mode growth during directional dendritic solidification aboard the KC-135

NASA's KC-135, which flies a cyclic parabolic route designed to furnish periods of low gravity alternating with periods of high gravity, has been used to directionally solidify a superalloy and a FE-C-Si alloy. Probable transient effects, due to the rapid changes in the gravity levels, must be taken into account. An effort is presently made to show that experimental design is especially critical in the case of dendritic directional solidification experiments in which mixed gravity modes occur; inappropriate design easily leads to anomalous structures and data.

Grugel, Richard N.↗
NASA NTRS1990

Free float acceleration measurements aboard NASA's KC-135 Microgravity Research Aircraft

A three-axis accelerometer subsystem, developed as part of a get-away-special Ga-As crystal growth system for the Space Shuttle, is described. Each axis of this subsystem contains a quartz flexure accelerometer capable of dc measurements, custom-designed measurement circuitry, a programmable microcomputer for measurement control and data reduction, and memory for recording data. The subsystem was flown as a free float experiment aboard the NASA KC-135 microgravity research aircraft, yielding measurements of accelerations during free float at a resolution of 10 micro-g.

Bellows, A. H.↗
NASA NTRS1991

Medical evaluations on the KC-135 1990 flight report summary

The medical investigations completed on the KC-135 during FY 1990 in support of the development of the Health Maintenance Facility and Medical Operations are discussed. The experiments are comprised of engineering evaluations of medical hardware and medical procedures. The investigating teams are made up of both medical and engineering personnel responsible for the development of medical hardware and medical operations. The hardware evaluated includes dental equipment, a coagulation analyzer, selected pharmaceutical aerosol devices, a prototype air/fluid separator, a prototype packaging and stowage system for medical supplies, a microliter metering system, and a workstation for minor surgical procedures. The results of these engineering evaluations will be used in the design of fleet hardware as well as to identify hardware specific training requirements.

Lloyd, Charles W.↗
NASA NTRS1992

KC-135 Large Motion Isolation Mount (LMIM)

Information on the Large Motion Isolation Mount (LMIM) to be used on the KC-135 is given in viewgraph form. Information given includes the cost per Kg-sec, program elements, the effect of aircraft acceleration level on free float time, and program objectives.

Tryggvason, Bjarni V.↗
NASA NTRS1992

Convective flow analysis on the KC-135 aircraft

A study conducting bouyancy driven convective flow experiments on the NASA KC-135 aircraft is presented. The response of a contained fluid (with an imposed temperature gradient) to changing g-levels during parabolic flight was obtained. Models for both transient and steady state flows were developed utilizing PC-based CFD software. Comparisons between the theoretical models and the physical observations are quite good.

Workman, Gary L.↗
NASA NTRS1991

Active member vibration control experiment in a KC-135 reduced gravity environment

An active member vibration control experiment in a KC-135 reduced gravity environment was carried out by the Air Force Flight Dynamics Laboratory and the Jet Propulsion Laboratory. Two active members, consisting of piezoelectric actuators, displacement sensors, and load cells, were incorporated into a 12-meter, 104 kg box-type test structure. The active member control design involved the use of bridge (compound) feedback concept, in which the collocated force and velocity signals are feedback locally. An impact-type test was designed to accommodate the extremely short duration of the reduced gravity testing window in each parabolic flight. The moving block analysis technique was used to estimate the modal frequencies and dampings from the free-decay responses. A broadband damping performance was demonstrated up to the ninth mode of 40 Hz. The best damping performance achieved in the flight test was about 5 percent in the fourth mode of the test structure.

Lawrence, C. R.↗
NASA NTRS1991

KC-135 materials handling robotics

Robot dynamics and control will become an important issue for implementing productive platforms in space. Robotic operations will become necessary for man-tended stations and for efficient performance of routine operations in a manned platform. The current constraints on the use of robotic devices in a microgravity environment appears to be due to an anticipated increase in acceleration levels due to manipulator motion and for safety concerns. The objective of this study will be to provide baseline data to meet that need. Most texts and papers dealing with the kinematics and dynamics of robots assume that the manipulator is composed of joints separated by rigid links. However, in recent years several groups have begun to study the dynamics of flexible manipulators, primarily for applying robots in space and for improving the efficiency and precision of robotic systems. Robotic systems which are being planned for implementation in space have a number of constraints to overcome. Additional concepts which have to be worked out in any robotic implementation for a space platform include teleoperation and degree of autonomous control. Some significant results in developing a robotic workcell for performing robotics research on the KC-135 aircraft in preperation for space-based robotics applications in the future were generated. In addition, it was shown that TREETOPS can be used to simulate the dynamics of robot manipulators for both space and ground-based applications.

Workman, Gary L.↗
NASA NTRS1993

Development and performance of a three degree of freedom large motion vibration isolation mount for the KC-135 aircraft

Scientific microgravity experiments conducted on platforms such as the Soviet Mir space station and the U.S. Space Shuttle indicated that the microgravity environment is contaminated with disturbances which result in the reduction of a gravity quality, from micro-g to milli-g. This paper describes the vibration isolation technology developed by the Canadian Space Agency, the 1DOF Large Motion Isolation Mount (LMIM) and the 3DOF LMIM, for the KC-135 aircraft. The results of the developmental activity are presented, and the applicability of the approach taken to the Space Shuttle, Space Station Freedom, and the Mir space station is discussed.

Tryggvason, B. V.↗
NASA NTRS1993

Medical evaluations on the KC-135 1991 flight report summary

The medical investigations completed on the KC-135 during FY 1991 in support of the development of the Health Maintenance Facility and Medical Operations are presented. The experiments consisted of medical and engineering evaluations of medical hardware and procedures and were conducted by medical and engineering personnel. The hardware evaluated included prototypes of a crew medical restraint system and advanced life support pack, a shuttle orbiter medical system, an airway medical accessory kit, a supplementary extended duration orbiter medical kit, and a surgical overhead canopy. The evaluations will be used to design flight hardware and identify hardware-specific training requirements. The following procedures were evaluated: transport of an ill or injured crewmember at man-tended capability, surgical technique in microgravity, transfer of liquids in microgravity, advanced cardiac life support using man-tended capability Health Maintenance Facility hardware, medical transport using a model of the assured crew return vehicle, and evaluation of delivery mechanisms for aerosolized medications in microgravity. The results of these evaluation flights allow for a better understanding of the types of procedures that can be performed in a microgravity environment.

Lloyd, Charles W.↗
NASA NTRS1994

Real-time tracking of objects for a KC-135 microgravity experiment

The design of a visual tracking system for use on the Extra-Vehicular Activity Helper/Retriever (EVAHR) is discussed. EVAHR is an autonomous robot designed to perform numerous tasks in an orbital microgravity environment. Since the ability to grasp a freely translating and rotating object is vital to the robot's mission, the EVAHR must analyze range image generated by the primary sensor. This allows EVAHR to locate and focus its sensors so that an accurate set of object poses can be determined and a grasp strategy planned. To test the visual tracking system being developed, a mathematical simulation was used to model the space station environment and maintain dynamics on the EVAHR and any other free floating objects. A second phase of the investigation consists of a series of experiments carried out aboard a KC-135 aircraft flying a parabolic trajectory to simulate microgravity.

Littlefield, Mark L.↗
NASA NTRS1994

Use of KC-135 parabolic flights to determine if brief changes in the gravity field can influence the phase and/or period of the circadian clock

In February 1994 a total of 10 hampsters flew on two separate KC-135 flights. On one flight, 25 animals experienced 31 parabolas, thus going through 31 cycles of hypergravity (up to about 1.8 G). On the other flight, the animals were exposed to 43 parabolas. fifty additional animals served as ground based controls and were treated in the same fashion as the experimental animals. The profiles of plasma GH, corisol and coricosterone from representative parabolic flight and ground control animals during pre-flight, in-flight, and post-flight conditions are depicted.

Turek, Fred W.↗
NASA NTRS1987

KC-135 aero-optical turbulent boundary layer/shear layer experiment revisited

The aero-optical effects associated with propagating a laser beam through both an aircraft turbulent boundary layer and artificially generated shear layers are examined. The data present comparisons from observed optical performance with those inferred from aerodynamic measurements of unsteady density and correlation lengths within the same random flow fields. Using optical instrumentation with tens of microsecond temporal resolution through a finite aperture, optical performance degradation was determined and contrasted with the infinite aperture time averaged aerodynamic measurement. In addition, the optical data were artificially clipped to compare to theoretical scaling calculations. Optical instrumentation consisted of a custom Q switched Nd:Yag double pulsed laser, and a holographic camera which recorded the random flow field in a double pass, double pulse mode. Aerodynamic parameters were measured using hot film anemometer probes and a five hole pressure probe. Each technique is described with its associated theoretical basis for comparison. The effects of finite aperture and spatial and temporal frequencies of the random flow are considered.

Craig, J.↗
NASA NTRS1991

Test equipment data package for the KC-135 fiber pulling apparatus

The Fiber Pulling Apparatus (FPA) is a device designed to produce continuous glass fibers from simulated lunar soil, and to determine the effects of reduced gravity, specifically 1/6 g on fiber formation and resultant properties. Briefly, pre-melt simulated lunar soil will be placed in a pint crucible and heated to 1200 C or higher, up to a maximum temperature of 1400 C. At a given temperature, a quartz fiber will be immersed into the melt and then pulled through a chill block and wound onto a cylindrical bobbin using a servo motor control. A high resolution video camera will record the fiber as it is being pulled. This assembly wil be enclosed in Plexiglas. Before fiber pulling commences, the apparatus will be backfilled with dry nitrogen. A separate data acquisition system will support this apparatus. This system will contain a personal computer, video recorder, and monitor. Temperature, acceleration, winding speed, and video images will be controlled and recorded using the data acquisition system. Thus, the FPA will consist of two hardware packages, the fiber production assembly and the data acquisition rack. The primary objective of this test is to determine the effects of 1/6 g on the formation of continuous glass fiber made from simulated lunar soil. Baseline studies using the FPA on the ground will provide a reference for the 1/6 g studies. Of particular interest will be the effect of 1/6 g on the free fluid zone where the fiber exits the crucible. In the fiber spinning parlance this zone is known as the upper jet region, where the boundary slope is greater than one tenth. The properties of the resulting glass fiber will depend on the jet shape as well as distributions of velocity, temperature and tension within the jet. It is unknown at this time how 1/6 g will effect these parameters.

Kosten, Sue↗
NASA NTRS1991

KC-135 zero-gravity two phase flow pressure drop - Experiments and modeling

A methodology for correcting raw pressure-drop data on the influence of acceleration on the instrumentation in two-phase flow thermal management systems is described. Such systems are now being considered as an alternative to conventional single-phase systems in future space missions because of the potential to reduce overall system mass, size, and pumping power requirements. Corrected pressure-drop measurements are presented and compared with predictions of two-phase flow pressure-drop models. A set of flow and acceleration conditions is defined for which the frictional pressure drop does not increase upon entry into 0-'g' pressure drop.

Lambert, Anne↗
NASA NTRS1999

Medical Operation KC-135 Familiarization Flight

As new personnel join the Medical Operations Branch, it is critical that they understand the effects of microgravity on medical procedures, hardware, and supplies. The familiarization flight provided new personnel with a better understanding of the effects of microgravity on (1) medical procedures, (2) patient and rescuer restraint, (3) medical fluids, and (4) medical training for space flight. The flight process also provided experience in flight proposal preparation, flight test plan preparation and execution, and final report preparation. In addition, first time flyers gained insight on their performance level in microgravity for future flights.

Dawson, Chris↗