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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.

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At least 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS2001

Airbag vent valve and system

An energy absorbing airbag system includes one or more vent valve assemblies for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event. Each vent valve assembly includes a cantilever spring that is flat in an unstressed condition and that has a free end portion. The cantilever spring is secured to an exterior surface of the airbag housing and flexed to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a vent port or a closure covering the vent port to seal the vent port until inflation gas pressure within the airbag reaches a preselected value determined by the preset force whereupon the free end portion of the cantilever spring is lifted from the vent port by the inflation gases within the airbag to vent the inflation gases from within the airbag. The resilience of the cantilever spring maintains a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event by causing the cantilever spring to vent gases through the vent port whenever the pressure of the inflation gases reaches the preselected value and by causing the cantilever spring to close the vent port whenever the pressure of the inflation gases falls below the preselected value.

Peterson, Leslie D.↗
NASA NTRS2009

Apollo-Era Life Rafts Save Hundreds of Sailors

The space shuttle is unique among spacecraft in that it glides back to Earth and lands like an airplane, usually touching ground near where it launched at Kennedy Space Center, but sometimes, in poor weather, gliding into the back-up landing site at Dryden Flight Research Center and then catching a ride back to the Cape on the back of a modified Boeing 747. Before NASA began flying the shuttle, though, astronauts had a longer, more involved trip back to base after a mission. Their capsule, called the command module, would plunge through the atmosphere before releasing a series of parachutes that would slow the craft enough for it to land on the water without too significant of an impact. Called a splashdown, this type of landing put the astronauts out in the ocean, where a specially designated U.S. Navy ship would then deploy a helicopter to retrieve the space travelers. Waiting for the rescue, the astronauts would release a highly visible marker dye into the water, then leave the command module and climb aboard a life raft. These early space pioneers had traveled thousands of miles and then landed safely back on Earth. The journey s end was in sight, but they had one more obstacle. The rotor downdraft from the helicopter coming to retrieve them, reaching sometimes as much as 100 knots per hour, was enough to flip a typical flat-bottomed life raft. Not willing to be thwarted after coming so far, NASA engineers began devising a solution. They knew they needed a highly stable inflatable raft capable of riding out the rough winds, and the solution was to make use of the most abundant resource available: water. Engineers at NASA s Johnson Space Center went to work designing and patenting a hydrodynamically stabilized ballast system that would prevent a life raft from tipping in choppy seas and fierce winds.

Source record↗
NASA NTRS2009

Foil Face Seal Testing

In the seal literature you can find many attempts by various researchers to adapt film riding seals to the gas turbine engine. None have been successful, potential distortion of the sealing faces is the primary reason. There is a film riding device that does accommodate distortion and is in service in aircraft applications, namely the foil bearing. More specifically a foil thrust bearing. These are not intended to be seals, and they do not accommodate large axial movement between shaft & static structure. By combining the 2 a unique type of face seal has been created. It functions like a normal face seal. The foil thrust bearing replaces the normal primary sealing surface. The compliance of the foil bearing allows the foils to track distortion of the mating seal ring. The foil seal has several perceived advantages over existing hydrodynamic designs, enumerated in the chart. Materials and design methodology needed for this application already exist. Also the load capacity requirements for the foil bearing are low since it only needs to support itself and overcome friction forces at the antirotation keys.

Munson, John↗
NASA NTRS2014

Life Cycle Analysis of Dedicated Nano-Launch Technologies

Recent technology advancements have enabled the development of small cheap satellites that can perform useful functions in the space environment. Currently, the only low cost option for getting these payloads into orbit is through ride share programs - small satellites awaiting the launch of a larger satellite, and then riding along on the same launcher. As a result, these small satellite customers await primary payload launches and a backlog exists. An alternative option would be dedicated nano-launch systems built and operated to provide more flexible launch services, higher availability, and affordable prices. The potential customer base that would drive requirements or support a business case includes commercial, academia, civil government and defense. Further, NASA technology investments could enable these alternative game changing options. With this context, in 2013 the Game Changing Development (GCD) program funded a NASA team to investigate the feasibility of dedicated nano-satellite launch systems with a recurring cost of less than $2 million per launch for a 5 kg payload to low Earth orbit. The team products would include potential concepts, technologies and factors for enabling the ambitious cost goal, exploring the nature of the goal itself, and informing the GCD program technology investment decision making process. This paper provides an overview of the life cycle analysis effort that was conducted in 2013 by an inter-center NASA team. This effort included the development of reference nano-launch system concepts, developing analysis processes and models, establishing a basis for cost estimates (development, manufacturing and launch) suitable to the scale of the systems, and especially, understanding the relationship of potential game changing technologies to life cycle costs, as well as other factors, such as flights per year.

nanolaunch↗
NASA NTRS2014

Enabling Dedicated, Affordable Space Access Through Aggressive Technology Maturation

A recent explosion in nano-sat, small-sat, and university class payloads has been driven by low cost electronics and sensors, wide component availability, as well as low cost, miniature computational capability and open source code. Increasing numbers of these very small spacecraft are being launched as secondary payloads, dramatically decreasing costs, and allowing greater access to operations and experimentation using actual space flight systems. While manifesting as a secondary payload provides inexpensive rides to orbit, these arrangements also have certain limitations. Small, secondary payloads are typically included with very limited payload accommodations, supported on a non interference basis (to the prime payload), and are delivered to orbital conditions driven by the primary launch customer. Integration of propulsion systems or other hazardous capabilities will further complicate secondary launch arrangements, and accommodation requirements. The National Aeronautics and Space Administration's Marshall Space Flight Center has begun work on the development of small, low cost launch system concepts that could provide dedicated, affordable launch alternatives to small, risk tolerant university type payloads and spacecraft. These efforts include development of small propulsion systems and highly optimized structural efficiency, utilizing modern advanced manufacturing techniques. This paper outlines the plans and accomplishments of these efforts and investigates opportunities for truly revolutionary reductions in launch and operations costs. Both evolution of existing sounding rocket systems to orbital delivery, and the development of clean sheet, optimized small launch systems are addressed. A launch vehicle at the scale and price point which allows developers to take reasonable risks with new propulsion and avionics hardware solutions does not exist today. Establishing this service provides a ride through the proverbial "valley of death" that lies between demonstration in laboratory and flight environments. This effort will provide the framework to mature both on-orbit and earth-to-orbit avionics and propulsion technologies while also providing dedicated, affordable access to LEO for cubesat class payloads.

Jones, Jonathan↗
NASA NTRS2021

IceNode: A Buoyant Vehicle for Acquiring Well-Distributed, Long-Duration Melt Rate Measurements Under Ice Shelves

Antarctic ice shelves buttress the Antarctic Ice Sheet from sliding into the ocean and significantly raising global sea level. However, the accelerating dynamics of ice shelf melt in a warming environment are poorly understood, and the collapse of Antarctic ice shelves remains one of the largest sources of uncertainty in global sea level rise projections. The cavities below Antarctic ice shelves are notoriously difficult to access, making model-based hypotheses about the relationship between ocean warming and greater ice shelf melting difficult to verify because of a lack of in-situ data to constrain model parameters and examine key assumptions. We present early progress on IceNode, a novel vehicle under development at the NASA Jet Propulsion Laboratory designed to acquire well-distributed, concurrent, long-duration melt rate measurements under ice shelves. IceNodes are deployed as an array from a ship at the shelf edge, and use variable buoyancy to ride melt-driven exchange currents far into the cavity. Once underneath their target, they release a ballast weight to become highly positively buoyant and attach to the underside of the ice shelf, where they acquire in-situ measurements of basal melt rate directly at the ice-ocean interface for a year or more. Finally, IceNodes detach from their landing structure and use variable buoyancy to ride melt-driven exchange currents back to open water, where they surface and transmit their mission data home. IceNodes are designed to be relatively low-cost, expendable, and have simple logistics, enabling scientists to deploy scalable arrays that simultaneously measure co-varying ice shelf melt and ocean conditions over large spatial areas, thereby providing an unprecedented view of ice shelf melt rate variability and its drivers.

Zapien, Xavier↗
NASA NTRS1958

Investigation of Inlet Control Parameters for an External-internal-compression Inlet from Mach 2.1 to 3.0

Investigation of the control parameters of an external-internal compression inlet indicates that the cowl-lip shock provides a signal to position the spike and to start the inlet over a Mach number range from 2.1 to 3.0. Use of a single fixed probe position to control the spike over the range of conditions resulted in a 3.7-count loss in total-pressure recovery at Mach 3.0 and 0 deg angle of attack. Three separate shock-sensing-probe positions were required to set the spike for peak recovery from Mach 2.1 to 3.0 and angles of attack from 0 deg to 6 deg. When the inlet was unstarted, an erroneous signal was obtained from the normal-shock control through most of the starting cycle that prevented the inlet from starting. Therefore, it was necessary to over-ride the normal-shock control signal and not allow the control to position the terminal shock until the spike was positioned.

POSITIONING EQUIPMENT↗
NASA NTRS1963

A Technique for Simulating Conditions of Walking and Performing Other Self-Locomotive Activities on the Lunar Terrain

One of the most important and probably the most interesting phase of a manned lunar mission will be the time the astronauts spend outside their vehicle on the moon's surface taking scientific measurements, exploring the surface features, surveying possible sites for a lunar base, inspecting their vehicle and preparing it for their return trip. Because the lunar gravity is only one-sixth that of the earth gravity, the explorers undoubtedly will have to adjust their accustomed methods of walking, climbing, jumping and performing other self-locomotive activities in order to carry out these various tasks. In as much as the over-all success of the lunar mission will depend to a large extent upon the self-reliance of the explorers, it will be necessary to have extensive knowledge of the effects of the moon's reduced gravity on the physical capabilities of man and of man's ability to adopt to the new environment prior to the planning and execution of the mission. At the present time there is a dearth of information on this subject due primarily to the lack of a practical technique for simulating the reduced gravity. Several techniques such as immersion in water and riding in an airplane flying a Keplerian trajectory have been used for zero-g or weightlessness studies to determine the physical capabilities of man but these techniques are limited in their usefulness either by restrictions imposed by the viscous effect of the water or by the short duration and small test area available in an airplane. Consequently, an effort was made at the NASA Langley Research Center to devise a new technique that would provide a realistic simlation of a reduced gravity for unlimited periods of time and allow freedom of movement over considerable distances. This paper concerns itself with a discussion of the newly developed simulation technique and a presentation of some preliminary results which were obtained utilizing a working model based on this scheme.

Hewes, Donald E.↗
NASA NTRS1966

Swiveling Lathe Jaw Concept for Holding Irregular Pieces

Clamp holds irregularly shaped pieces in lathe chuck without damage and eliminates excessive time in selecting optimum mounting. Interchangeable jaws ride in standard jaw slots but swivel so that the jaw face bears evenly against the workpiece regardless of contour. The jaws can be used on both engine and turret lathes.

David, J.↗
NASA NTRS1966

Special mandrel permits uniform welding of out-of-round tubing

Clamp holds irregularly shaped pieces in lathe chuck without damage and eliminates excessive time in selecting optimum mounting. Interchangeable jaws ride in standard jaw slots but swivel so that the jaw face bears evenly against the workpiece regardless of contour. The jaws can be used on both engine and turret lathes.

Dor, M. E.↗
NASA NTRS1968

Swing arm carrier protects flexible lines during test item rotation

Swing arm carrier provides protection for flexible lines /fluid, electrical, RF/ connected to a test item that must be rotated through 360 degrees during test. It uses five gates riding on pivots to permit rotation of flexible lines through arcs of plus 180 degrees and minus 180 degrees.

Ward, D. P.↗
NASA NTRS1969

Methods of Achieving and Maintaining Physical Fitness for Prolonged Space Flight

This final summary report covers the five experiments that were conducted over a 24-month period beginning May 1, 1967 and ending April 30, 1969. Experiment I revealed that running and riding a bicycle ergometer produced similar gains in physical fitness variables. In Experiment I the subjects exercising at a 180 heart rate made a greater improvement in physical fitness than did those exercising a t a 140 or 160 heart rate. In Experiment II the subjects who exercised sixty minutes per day made greater gains on specified components of physical fitness than did those who exercised twenty or forty minutes per day, twelve times per week made greater gains on specified components of physical fitness than did those who exercised three or six times per week. In Experiment V, it was found that subjects could maintain a moderate level of fitness by exercising at a pulse rate of 160 beats per minute for twenty-minute periods three times per week, that subjects who "overtrained" by exercising twice daily to near exhaustion increased in fitness and that those subjects who discontinued training decreased in fitness.

Olree, Harry D.↗
NASA NTRS1970

Pilot impressions of lifting body vehicles

Piloting aspects of the lifting body vehicles are discussed in this paper by two of the pilots assigned to the flight program. Subjects discussed include: approach, landing, and energy management considerations; field of view requirements, stability considerations, and vehicle riding qualities, including the effects of turbulence. Remarks pertinent to the various subject areas are made by each pilot.

William H Dana↗
NASA NTRS1972

Analysis of Morgantown vehicle steering control

The proposed Morgantown public transportation system will use a fleet of computer-controlled vehicles operating on a separate dedicated network of roadways called a guideway. An automatic steering system on each vehicle will permit the traversal of the proposed route of various guideway sections. A preliminary study was made to analyze the steering control for the Morgantown vehicles. The primary requirement was to design an automatic steering system that would achieve a smooth ride and eliminate the need for excess margin in the guideway width. Front and rear wheel steering and front and rear sensing capabilities were assumed in the analysis. The system finally adopted front and rear wheel steering and front sensing was shown by computer simulation and vehicle steering experiments to be adequate.

Lin, H. S.↗
NASA NTRS1972

Physiological response in pilot/back-seat man during aerial combat maneuvers in F-4E aircraft.

Comparison of objective/subjective physiological data between the pilot and the back-seat man during training within the G maneuvering envelope. It appears that the psychological requirements for the pilot to be mentally alert and physiologically adapted to a continually changing environment places additional responsibility on him to the extent the physiological signs monitored are indicative of a high stress condition and are increased by a significant amount over the back-seat man who is, in most instances, riding passively.

Leverett, S. D., Jr.↗
NASA NTRS1972

Active controls - Changing the rules of structural design.

Approaches making use of aerodynamic surfaces in combination with advanced flight computers, and electrohydraulic systems could be used to improve economics of commercial aircraft operation, smooth the passenger's ride, reduce terminal-area noise, and ease terminal-area congestion. This emerging technology is becoming known as active controls technology. Maximum benefits from active controls can come only by considering controls early in the design cycle. Active controls can save weight by reducing the structural strength necessary. Some of the technical benefits of active controls would increase return on investment and raise profits. Details of a proposed active controls research program are discussed.

Hood, R. V.↗