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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 415 records · Page 23
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Space Station attitude control - An overview of requirements and solutions

Attitude control and various structural aspects of NASA's permanent manned Space Station are discussed in the framework of design flexibility, obsolescence as a deterent to a long operational life, modularity, and autonomy. Among the variable factors of specific importance, consideration is given to internal factors, such as inertial variations (up to 400 percent), center of mass movements (up to 28 m), and shifts in modal characteristics, as well as to external torque shifts associated with aerodynamic moments and gravity gradients. The compatibility among multiple-user requirements is also considered. As the Station is a low-orbit spacecraft, its attitude will be greatly affected by the inhomogeneity of the atmosphere, placing a priority on the attitude control techniques. A combination of passive (spring-mass-damper suspension systems) and active (sensor/disturbance-canceling device) systems are expected to be used.

Buchanan, H. J.↗
NASA NTRS1991

AIAA/IKI Microgravity Science Symposium, 1st, Moscow, USSR, May 13-17, 1991, Proceedings

The state of the art of microgravity science is examined in reviews and reports. Consideration is given to fluid physics; modeling and numerical analysis; crystal growth of electronic materials, proteins, metals, alloys, glasses, and ceramics; biotechnology, combustion science, microgravity hardware, and fundamental phenomena; and education. Particular attention is given to containerless science and technology, a low-gravity two-phase flow with heat transfer, numerical investigation on Benard instability in a finite liquid layer, synthesis and crystallization of refractory compounds from solutions in metallic melts under microgravitation conditions, the long duration protein crystallization experiment aboard the Mir Space Station, directional solidification in immiscible systems, formation of periodic layer structure in oxide melts under different gravity values, opposed flow flame spread in normal, enhanced, and reduced gravity, automatic equipment for semiconductor production in space, and consort and joust sounding rocket missions.

Source record↗
NASA NTRS1982

Radio interferometric detection of a traveling ionospheric disturbance excited by the explosion of Mount St. Helens

A large-amplitude traveling ionospheric disturbance (TID) was detected over Owens Valley, California, on May 18, 1980, by a highly sensitive very long baseline interferometry (VLBI) radio astronomy experiment. This TID is interpreted as the response of the ionosphere to a gravity wave excited in the neutral atmosphere by the explosion of Mount St. Helens that took place at 1532 UT on that day. A model, invoking the point-excitation of internal gravity waves in an isothermal atmosphere, which fits observations of the TID at several other stations, leads to identification of the features observed in the VLBI data. Small-amplitude higher-frequency changes in the ionosphere were detected for several hours after the passage of the large-amplitude Mount St. Helens TID, but it is not clear whether these were excited by the passage of the gravity wave or were background fluctuations.

Roberts, D. H.↗
NASA NTRS2016

Post-Flight Back Pain Following International Space Station Missions: Evaluation of Spaceflight Risk Factors

INTRODUCTION Back pain during spaceflight has often been attributed to the lengthening of the spinal column due to the absence of gravity during both short and long-duration missions. Upon landing and re-adaptation to gravity, the spinal column reverts back to its original length thereby causing some individuals to experience pain and muscular spasms, while others experience no ill effects. With International Space Station (ISS) missions, cases of back pain and injury are more common post-flight, but little is known about the potential risk factors. Thus, the purpose of this project was to perform an initial evaluation of reported post-flight back pain and injury cases to relevant spaceflight risk factors in United States astronauts that have completed an ISS mission. METHODS All US astronauts who completed an ISS mission between Expeditions (EXP) 1 and 41 (2000-2015) were included in this evaluation. Forty-five astronauts (36 males and 9 females) completed 50 ISS missions during the study time period, as 5 astronauts completed 2 ISS missions. Researchers queried medical records of the 45 astronauts for occurrences of back pain and injury. A case was defined as any reported event of back pain or injury to the cervical, thoracic, lumbar, sacral, or coccyx spine regions. Data sources for the cases included the Flight Medicine Clinic's electronic medical record; Astronaut Strength, Conditioning and Rehabilitation electronic documentation; the Private Medical Conference tool; and the Space Medicine Operations Team records. Post-flight cases were classified as an early case if reported within 45 days of landing (R + 45) or a late case if reported from R + 46 to R + 365 days after landing (R + 1y). Risk factors in the astronaut population for back pain include age, sex, prior military service, and prior history of back pain. Additionally, spaceflight specific risk factors such as type of landing vehicle and onboard exercise countermeasures were included to evaluate their contribution to post-flight cases. Prior history of back pain included back pain recorded in the medical record within 3 years prior to launch. Landing vehicle was included in the model to discern if more astronauts experienced back pain or injury following a Shuttle or Soyuz landing. Onboard exercise countermeasures were noted for those astronauts who had a mission following 2009 deployment of the Advanced Resistive Exercise Device (aRED) (EXP 19 to 41). T-test and chi-squared tests were performed to evaluate the association between each individual risk factor and post-flight case. Logistic regression was used to evaluate the combined contribution of all the risk factors on post-flight cases. Separate models were calculated for cases reported by R + 45 and R + 1y. RESULTS During the study time period, there were 13 post-flight cases reported by R + 45 and an additional 5 reported by R + 1y. Most of these cases have been reported since EXP 19 with 10 cases by R + 45 and 4 by R + 1y. Individual risk factors of age, sex, landing vehicle, and prior military service were not significantly associated with post-flight cases identified at R + 45 or R + 1y (p greater than 0.05). Having back pain or injury within 3 years prior to launch significantly increased the likelihood of becoming a case by R + 1y (p = 0.041), but not at R+45 (p=0.204). Additionally, astronauts who experienced onboard exercise countermeasures that included aRED had a significantly increased risk of becoming a case at R + 45 (p = 0.024) and R + 1y (p=0.003). Multiple logistic regression evaluating all the risk factors for cases identified no significant risk factors at either the R + 45 or R + 1y time period (p greater than 0.05). Overall model fit was poor for both the R + 45 (R(exp 2) = 0.132) and R + 1y (R(exp 2) = 0.186) cases showing that there are risk factors not represented in our model. CONCLUSIONS Regardless of cause, post-flight cases are reported more often since aRED was deployed in 2009. This may reflect improved documentation or unidentified risk factors. No spaceflight risk factor explains the data fully. Post-flight cases are probably due to multi-faceted factors that are not easily elucidated in the medical data.

Laughlin, M. S.↗
NASA NTRS1988

Study of toluene rotary fluid management device and shear flow condenser performance for a space-based organic Rankine power system

Management of two-phase fluid and control of the heat transfer process in microgravity is a technical challenge that must be addressed for an orbital Organic Rankine Cycle (ORC) application. A test program was performed in 1-g that satisfactorily demonstrated the two-phase management capability of the rotating fluid management device (RFMD) and shear-flow condenser. Operational tests of the RFMD and shear flow condenser in adverse gravity orientations, confirmed that the centrifugal forces in the RFMD and the shear forces in the condenser were capable of overcoming gravity forces. In a microgravity environment, these same forces would not have to compete against gravity and would therefore be dominant. The specific test program covered the required operating range of the Space Station Solar Dynamic Rankine Cycle power system. Review of the test data verified that: fluid was pumped from the RFMD in all attitudes; subcooled states in the condenser were achieved; condensate was pushed uphill against gravity; and noncondensible gases were swept through the condenser.

Havens, Vance↗
NASA NTRS2017

Mixed Convection Blowoff Limits as a Function of Oxygen Concentration and Upward Forced Stretch Rate for Burning Pmma Rods of Various Sizes

Normal gravity flame blowoff limits in an axisymmetric pmma rod geometry in upward axial stagnation flow are compared with microgravity Burning and Suppression of Solids II (BASS-II) results recently obtained aboard the International Space Station. This testing utilized the same BASS-II concurrent rod geometry, but with the addition of normal gravity buoyant flow. Cast polymethylmethacrylate (pmma) rods of diameters ranging from 0.635 cm to 3.81 cm were burned at oxygen concentrations ranging from 14 to 18 by volume. The forced flow velocity where blowoff occurred was determined for each rod size and oxygen concentration. These blowoff limits compare favorably with the BASS-II results when the buoyant stretch is included and the flow is corrected by considering the blockage factor of the fuel. From these results, the normal gravity blowoff boundary for this axisymmetric rod geometry is determined to be linear, with oxygen concentration directly proportional to flow speed. We describe a new normal gravity upward flame spread test method which extrapolates the linear blowoff boundary to the zero stretch limit to resolve microgravity flammability limits, something current methods cannot do. This new test method can improve spacecraft fire safety for future exploration missions by providing a tractable way to obtain good estimates of material flammability in low gravity.

blowoff↗
NASA NTRS2012

Directionally Solidified Aluminum - 7 wt% Silicon Alloys: Comparison of Earth and International Space Station Processed Samples

Primary dendrite arm spacings of Al-7 wt% Si alloy directionally solidified in low gravity environment of space (MICAST-6 and MICAST-7: Thermal gradient approx. 19 to 26 K/cm, Growth speeds varying from 5 to 50 microns/s show good agreement with the Hunt-Lu model. Primary dendrite trunk diameters of the ISS processed samples show a good fit with a simple analytical model based on Kirkwood s approach, proposed here. Natural convection, a) decreases primary dendrite arm spacing. b) appears to increase primary dendrite trunk diameter.

Grugel, Richard N,↗
NASA NTRS1971

Short arc optical survey techniques

The effect of the gravity parameter, mu, the choice and local survey of the fixed origin station, and the choice of initial datum on the results of short arc satellite survey adjustments were investigated using GEOS 1 MOTS optical observations from 13 stations. It is concluded that each of these parameters has an effect on derived network scale on the order of 0.000002 for the nominal variations used. A particular solution using assumed best available values for these parameters is recommended.

Berbert, J. H.↗
NASA NTRS1984

Growth and differentiation of mammalian embryonic tissues exposed to hypergravity in vivo and in vitro

In about 10 years or so, men and women from Earth will be long-term inhabitants of a space station aboard which plants and animals will be growing and developing in gravities other than that of Earth. The effect of gravitational changes on development was examined. It is indicated that differentiation is speeded up under excess G and slowed in low or null G. The effects of exposure to excess gravity on fusion of the embryonic mouse secondary palate were studied. During fusion, the palatal shelves first adhere by means of glycoproteins appearing along the medial epithelial edge (MEE). The contacting epithelia then reorganize and undergo programmed cell death, allowing the underlying mesenchymes to come in contact. The process of cell death occurs in vitro at about the same rate that it occurs in vivo.

Duke, P. J.↗
NASA NTRS1985

Space Station life science research facility - The vivarium/laboratory

Research opportunities possible with the Space Station are discussed. The objective of the research program will be study gravity relationships for animal and plant species. The equipment necessary for space experiments including vivarium facilities are described. The cost of the development of research facilities such as the vivarium/laboratory and a bioresearch centrifuge is examined.

Hilchey, J. D.↗
NASA NTRS1987

Social factors in space station interiors

Using the example of the chair, which is often written into space station planning but which serves no non-cultural function in zero gravity, difficulties in overcoming cultural assumptions are discussed. An experimental approach is called for which would allow designers to separate cultural assumptions from logistic, social and psychological necessities. Simulations, systematic doubt and monitored brainstorming are recommended as part of basic research so that the designer will approach the problems of space module design with a complete program.

Cranz, Galen↗
NASA NTRS1987

Kinetics in a turbulent nebular cloud

Model calculations, which include the effects of turbulence during subsequent solar nebula evolution after the collapse of a cool interstellar cloud, can reconcile some of the apparent differences between physical parameters obtained from theory and the cosmochemical record. Two important aspects of turbulence in a protoplanetary cloud include the growth and transport of solid grains. While the physical effects of the process can be calculated and compared with the probable remains of the nebula formulation period, the more subtle effects on primitive grains and their survival in the cosmochemical record cannot be readily evaluated. The environment offered by the Space Station (or Space Shuttle) experimental facility can provide the vacuum and low gravity conditions for sufficiently long time periods required for experimental verification of these cosmochemical models.

Mackinnon, Ian D. R.↗
NASA NTRS1989

The space station tethered elevator system

The optimized conceptual engineering design of a space station tethered elevator is presented. The elevator is an unmanned mobile structure which operates on a ten kilometer tether spanning the distance between the Space Station and a tethered platform. Elevator capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The potential uses, parameters, and evolution of the spacecraft design are discussed. Engineering development of the tethered elevator is the result of work conducted in the following areas: structural configurations; robotics, drive mechanisms; and power generation and transmission systems. The structural configuration of the elevator is presented. The structure supports, houses, and protects all systems on board the elevator. The implementation of robotics on board the elevator is discussed. Elevator robotics allow for the deployment, retrieval, and manipulation of tethered objects. Robotic manipulators also aid in hooking the elevator on a tether. Critical to the operation of the tethered elevator is the design of its drive mechanisms, which are discussed. Two drivers, located internal to the elevator, propel the vehicle along a tether. These modular components consist of endless toothed belts, shunt-wound motors, regenerative power braking, and computer controlled linear actuators. The designs of self-sufficient power generation and transmission systems are reviewed. Thorough research indicates all components of the elevator will operate under power provided by fuel cells. The fuel cell systems will power the vehicle at seven kilowatts continuously and twelve kilowatts maximally. A set of secondary fuel cells provides redundancy in the unlikely event of a primary system failure. Power storage exists in the form of Nickel-Hydrogen batteries capable of powering the elevator under maximum loads.

Anderson, Loren A.↗
NASA NTRS1989

Microgravity sensitivities for Space Station ECLS subsystems

This report presents a review of the Space Station Environmental Control and Life Support subsystems (ECLSS) for sensitivity to low gravity environments. The object of this review is to categorize sensitivity areas and to quantify the risks. This review addresses all processes from a top level view and then examines in more detail those areas which were considered potential risks. The study has concentrated on the primary function of the subsystems which may be significant to the performance of the particular component and does not address integration of the subsystem and/or the mechanical aspects of the designs. The areas of primary concern were the Atmosphere Revitalization (AR), Water Recovery and Management (WRM), and the Waste Management (WM) subsystems.

Bangham, M. E.↗
NASA NTRS1989

Space Station tethered elevator system

The optimized conceptual engineering design of a space station tethered elevator is presented. The tethered elevator is an unmanned, mobile structure which operates on a ten-kilometer tether spanning the distance between Space Station Freedom and a platform. Its capabilities include providing access to residual gravity levels, remote servicing, and transportation to any point along a tether. The report discusses the potential uses, parameters, and evolution of the spacecraft design. Emphasis is placed on the elevator's structural configuration and three major subsystem designs. First, the design of elevator robotics used to aid in elevator operations and tethered experimentation is presented. Second, the design of drive mechanisms used to propel the vehicle is discussed. Third, the design of an onboard self-sufficient power generation and transmission system is addressed.

Haddock, Michael H.↗
NASA NTRS1965

Review of the XB-70 Flight Program

Although the major NASA research effort is directed toward XB-70-2, which will not enter its flight program until the summer of 1965, a limited amount of information is available from the early flights of the XB-70-1 airplane. Initial take-off and landing performance data have generally substantiated predictions and indicate no unforeseen problems for this class of vehicle. Vertical velocities at impact are of the same order of magnitude as those being experienced by present-day subsonic jets. The XB-70 distances from brake release to lift-off graphically illustrate the advantage of the increased thrust-weight ratio of the supersonic cruise vehicle. The landing loads are well within the design limits up to the highest vertical velocities encountered to date, and recorded data show the response at the pilot station to be somewhat greater than that recorded at the center of gravity. Persistent shaking has been encountered in flight at subsonic speed. The cause of the excitation is not known at present but the oscillation does not appear to be conventional buffeting. The oscillation occurrence drops off appreciably at supersonic speeds and can be correlated with atmospheric turbulence. The stability and control characteristics at subsonic speeds appear satisfactory with stability augmentation on and off. A longitudinal trim discrepancy from predictions has been noted in the transonic region which appears to be decreasing with increasing supersonic speed. The supersonic handling qualities are considered adequate with stability augmentation off; however, sensitive lateral control has resulted in small pilot-induced oscillations.

Thomas R. Sisk↗
NASA NTRS2013

Kinect Engineering with Learning (KEWL)

According to a Nielsen survey at the time of this reporting, 41% of all households have a game console. This is one market in which NASA has been absent from education and outreach efforts. Kinect Engineering with Learning (KEWL) is made to enter into that market and bring NASA education and outreach to a very familiar venue. KEWL creates an education and outreach experience that is more participatory, both in a school and museum environment. KEWL is a set of applications that runs on an Xbox 360 using the Kinect controller used for education and outreach. These applications currently include: Train R2, a visual simulation of Robonaut 2 that allows students to control a virtual R2 in a game environment; Drive R2, an interface using the Xbox 360 and Kinect controller that allows students to control the real R2 using the methods they learned playing Train R2; ISS experience, a visual tour of the interior of the International Space Station where students use their body to fly through the virtual ISS; Gravity Ball, a simulation of throwing balls in the gravity of different planets; Solar Array repair, a simulation of the simplified STS-121 solar array repair mission; and PlaySpace, a Mars/Moon application that allows students to experience different aspects of Mars/Moon. Users can "fly through" the ISS using their body, allowing an experience similar to what an astronaut would have on orbit. In PlaySpace, users can fly over the surface of Mars and view surface data obtained by Mars rovers. Users of Train R2 and Drive R2 can experience what it is like to control a robot over a distance with a time delay, simulating the time delay that would occur between ground control and an on-orbit robot. The initial ISS experiences were built using parts of code from the NASA Enigma software. The models used in these experiences were also from the Integrated Graphics Operations and Analysis Lab model database. The PlaySpace experience incorporates surface data obtained from NASA rovers and satellites and was built by NASA JPL.

Goza, Sharon↗
NASA NTRS2016

Astrobee: Space Station Robotic Free Flyer

Astrobee is a free flying robot that will fly inside the International Space Station and primarily serve as a research platform for robotics in zero gravity. Astrobee will also provide mobile camera views to ISS flight and payload controllers, and collect various sensor data within the ISS environment for the ISS Program. Astrobee consists of two free flying robots, a dock, and ground data system. This presentation provides an overview, high level design description, and project status.

Free flight↗