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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 181 records · Page 10
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NASA NTRS1973

First Year Projects and Activities of the Environmental Remote Sensing Applications Laboratory (ERSAL)

Activities, pilot projects, and research that will effectively close the gap between state-of-the-art remote sensing technology and the potential users and beneficiaries of this technological and scientific progress are discussed in light of the first year of activity. A broad spectrum of resource and man-environment problems are described in terms of the central thrust of the first-year program to support land use planning decisions with information derived from the interpretation of NASA highlight and satellite imagery.

Poulton, C. E.↗
NASA NTRS1973

The first Earth Resources Technology Satellite (ERTS-1)

The first Earth Resources Technology Satellite (ERTS-1) makes images of the earth's surface in four portions of the electromagnetic spectrum with sufficient spatial resolution and with a minimum of geometric distortions, so that these images may be applied experimentally to the study of geophysical processes relating to earth resources, to the exploration and conservation of these resources, and to the assessments of environmental stresses. During the first six months of operation, ERTS-1 has imaged 6.5 million square kilometers of the earth's surface every day, covering most major land masses and coastal zones as well as both polar regions of this planet. These images as well as the results of their analyses are available to all people throughout the world. Scientific investigators of all countries have been invited to participate in the utilization of ERTS-1 observations. Many of them have already demonstrated the great efficiency, economy, and reliability of making earth surveys from space.

Nordberg, W.↗
NASA NTRS1972

Nonstationary envelope process and first excursion probability.

The definition of stationary random envelope proposed by Cramer and Leadbetter, is extended to the envelope of nonstationary random process possessing evolutionary power spectral densities. The density function, the joint density function, the moment function, and the crossing rate of a level of the nonstationary envelope process are derived. Based on the envelope statistics, approximate solutions to the first excursion probability of nonstationary random processes are obtained. In particular, applications of the first excursion probability to the earthquake engineering problems are demonstrated in detail.

Yang, J.-N.↗
NASA NTRS1973

Microwave signatures of first-year and multiyear sea ice.

A combination of remote sensing from an aircraft and simultaneous surface measurements have confirmed the feasibility of identifying old and new sea ice according to its emission of thermal radiation at wavelengths between 0.3 and 3 cm. Emissivity of first-year thick ice with a surface temperature of about 260 K is 0.95 or greater for wavelengths between 0.81 and 11 cm; the emissivity of multiyear ice is 0.8 at 0.81 cm and 0.95 at 11 cm, increasing monotonically in this wavelength interval. The ease with which multiyear ice can be distinguished from first-year ice using a passive microwave radiometer is demonstrated by comparing mosaics prepared both from photographs and images of 1.55-cm radiation.

Gloersen, P.↗
NASA NTRS1974

First heated jettison test on the Centaur standard shroud

The first in a planned series of heated jettison tests on the Centaur Standard Shround was conducted at NASA Plum Brook Station's Space Power Facility on November 19, 1973. The first 250-second portion of the test sequence involved heating the shroud with a specially-built fixture designed to provide a simulation of the heating environment encountered by the shroud during its ascent through the earth's atmosphere. The two heater halves, which were mounted on a rail system, were then retracted. This was followed by the jettison of the two shroud halves into catch nets positioned at 90 deg to the heater rails. The condition which made this test unique compared to the planned subsequent tests was the location of the maximum thermal line at 32 deg from the shroud separation plane. Information on the test hardware, configuration, and sequence is presented. Shroud thermal and deflection data encountered during the heating portion of the test sequence is compared with free-skin design temperatures in various graphical formats.

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NASA NTRS1974

NASA-marks 5th anniversary of first lunar landing

The accomplishments of the Apollo 11 Flight are presented as a tribute to the fifth anniversary of the first landing on the moon. The document contains: (1) a general description of the Apollo 11 Flight, (2) Presidential statements, (3) Apollo historical summary, (4) Apollo mission facts, (5) information on astronauts who are no longer in the program, and (6) transcripts of the landing sequence and first extravehicular activities on the moon.

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NASA NTRS1973

First measurements of electron temperature in the D region with a symmetric double probe

Measurement of the altitude profile of electron temperature in the ionospheric D region with the aid of a symmetric double probe flown on a Nike-Cajun payload launched on Oct. 13, 1971. The procedure for determining the electron temperature from the parameters of the double probe's current-voltage characteristic under conditions of nonnegligible ion-atom collision frequencies is described. It is shown that in its first lower ionospheric application the technique of the symmetric double probe has yielded the lowest values of electron temperature yet measured and has provided the very first direct measurement of electron temperature in the D region.

Szuszczewicz, E. P.↗
NASA NTRS1959

Preliminary Study of Capsule Recovery for the First Series of Project Mercury Orbital Flights

This report contains the results of a preliminary study of the search and. recovery operations required. for the safe and. expeditious return of the Mercury Recovery Capsule in the first series of orbital flights. The study is concerned primarily with the high-probability impact areas in the Atlantic Ocean. Emphasis is placed on safe recovery within reasonable time at least cost. A preliminary study of this nature is not able to provide final answers to all of the problems; the report instead constitutes a "first look" at the overall operation. Much of the report is therefore devoted to basic data, the building blocks from which recovery systems can be assembled and evaluated. These include the performance characteristics, reliability, and cost of the vehicles and equipment which may be used, and their compatibility with one another, with the capsule, and with the expected environment. The availability of vehicles and equipment has also been considered., although it is appreciated. that this may change from week to week where the forces are drawn from the military services. consideration of alternative vehicles, equipments, and systems, and their evaluation from the standpoint of effectiveness and. cost. While the equipment considered. is generally expected to be operational throughout 1960, consideration is also given to more advanced schemes which might effect reductions in recovery time, cost, or dependence upon the military forces.

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NASA NTRS1975

Skylab experiment M-092 - Results of the first manned mission

Blood pressure, heart rate, and percentage increase in leg volume were continuously recorded for the Inflight Lower Body Negative Pressure (LBNP) experiment conducted during the first manned Skylab mission. Data were collected over a 5-month preflight period as well as at approximately 3-day intervals throughout the mission. Individual variations in cardiovascular responses to LBNP during the preflight period continued to be demonstrated inflight, and measurements of the calf showed that a large volume of fluid was shifted out of the legs early in the flight. A much greater increase in leg volume occurred during inflight LBNP than in preflight tests. Resting heart rates tended to be low early in the flight and to increase slightly as it progressed, while resting blood pressure varied. The LBNP protocol was a greater stress inflight, and the tests had to be stopped early on three occasions due to impending syncopal reactions. Inflight LBNP responses seemed to predict the degree of postflight orthostatic intolerance. Postflight responses to LBNP during the first 48 hours were characterized by marked elevations in heart rate, instability in blood pressure, and considerably elevated systolic and diastolic pressures both at rest and during stress.

Johnson, R. L.↗
NASA NTRS1976

The first Spacelab mission

The purpose of Spacelab, an Orbiter-mounted NASA/ESA laboratory, is to include in the Space Transportation System (STS) a payload carrier with maximum flexibility to accommodate multidisciplinary scientific payloads. The major Spacelab configurations obtained by combination of two basic elements, the module and pallet, are described along with the anticipated program of experiments and payloads, and mission management general concept. The first Spacelab 7-day mission is scheduled for flight in the second half of 1980, with the primary objective being to verify system performance capabilities. Detailed attention is given to the payload mission management responsibilities for the first flight, including program control, science management, payload interfaces, integrated payload mission planning, integration requirements, payload specialist training, payload integration, launch site integration, payload flight/mission operations, and postmission activities. The Spacelab configuration (including the long module and one pallet) and the overall schedule for this mission are presented.

Pace, R. E., Jr.↗
NASA NTRS1976

First-Order-hold interpolation digital-to-analog converter with application to aircraft simulation

Those who design piloted aircraft simulations must contend with the finite size and speed of the available digital computer and the requirement for simulation reality. With a fixed computational plant, the more complex the model, the more computing cycle time is required. While increasing the cycle time may not degrade the fidelity of the simulated aircraft dynamics, the larger steps in the pilot cue feedback variables (such as the visual scene cues), may be disconcerting to the pilot. The first-order-hold interpolation (FOHI) digital-to-analog converter (DAC) is presented as a device which offers smooth output, regardless of cycle time. The Laplace transforms of these three conversion types are developed and their frequency response characteristics and output smoothness are compared. The FOHI DAC exhibits a pure one-cycle delay. Whenever the FOHI DAC input comes from a second-order (or higher) system, a simple computer software technique can be used to compensate for the DAC phase lag. When so compensated, the FOHI DAC has (1) an output signal that is very smooth, (2) a flat frequency response in frequency ranges of interest, and (3) no phase error. When the input comes from a first-order system, software compensation may cause the FOHI DAC to perform as an FOHE DAC, which, although its output is not as smooth as that of the FOHI DAC, has a smoother output than that of the ZOH DAC.

Cleveland, W. B.↗
NASA NTRS1976

First order impulsive solutions

A mathematically rigorous derivation is given of first order corrections to multi-impulse approximations to the solutions to space flight optimization problems with bang-bang control. The rocket was subjected to an inverse square gravitational force and to a thrust force with constant magnitude. The mass decreased linearly with time. An optimal impulsive solution was obtained for a problem with given initial and final conditions. The method was then used to obtain first-order corrections to the initial values of the costate variables. Indications are given on how the theory may be extended to higher order corrections. The theory was applied to intercept and rendezvous problems.

Andrus, J. F.↗
NASA NTRS1977

Spectral absorption coefficients for the fundamental and first overtone vibration-rotation bands of CN

A previous measurement of the transition moment of the fundamental vibration-rotation band of CN is combined with theoretical calculations of relative vibrational transition probabilities in order to compute absorption coefficients for the CN fundamental and first-overtone bands. Line strengths for 121 lines in each branch of all fundamental and first-overtone bands with upper-transition states not greater than 6 are calculated for temperatures of 2000, 3000, and 4000 K; these line strengths are presented as averaged over 8-kayser intervals. The relative vibrational transition moments are placed on an absolute scale, and the wavenumbers of the band origins and heads are given

Bailey, W. L.↗
NASA NTRS1977

An optimal Space Shuttle ascent trajectory for the first orbital flight test

An optimal solution of the ascent trajectory of the Space Shuttle for the first orbital flight test is presented; the optimization is a minimum propellant, four-control problem in yaw angle, roll angle, pitch angle and vacuum thrust of each Space Shuttle main engine. Piecewise linear segments with juncture points treated as parameters are employed to model the controls. Equations of motion for a three-dimensional flight with pitch plane moment balance about an oblate are integrated numerically with a fourth-order Runge-Kutta method; two- and one-dimensional cubic spline function curve fits of aerodynamic coefficients are used during the first and second stages, respectively. The constraint minimization problem is solved with the Davidon-Fletcher-Powell function method.

Johnson, I. L., Jr.↗
NASA NTRS1977

Characteristics of first order shock induced magnetic transitions in iron and discrimination from TRM

Reflected light microscopy provides information on first-order shock transitions in iron and iron-nickel and permits discrimination of microstructures due to shock transitions from those imparted by thermal transitions. In addition, thin-foil electron microscopy is used to characterize magnetic transitions in fine-particle iron. First-order magnetic phase changes, such as that from the antiferromagnetic face centered cubic state to the ferromagnetic body centered cubic state, are studied with the aim of calibrating the shock and thermal mechanisms of magnetization in iron with a particle size range between 250 and 1200 A. The efficiency of remanence due to shock transition is also estimated.

Wasilewski, P.↗
NASA NTRS1978

The 25 kW power module - First step beyond the baseline STS

The backbone of the first reusable Space Transportation System (STS) is the Space Shuttle. The 25 kW Power Module is currently being defined by NASA as the first significant increment in capability beyond the baseline STS and is to be available for use in 1983. The Power Module is an orbit-based space system which will augment the capability of the Space Shuttle Orbiter to support Spacelab sortie missions and will provide a unique free-flying mode for a variety of payloads which require high capability, long duration, and man-tended operation. The Power Module will make it possible for the Space Shuttle Orbiter and Spacelab to remain on-orbit for periods of time significantly in excess of that provided by the baseline STS (7 days) without major penalty to the Shuttle and its payload.

Mordan, G. W.↗
NASA NTRS1978

LDAR observations of a developing thunderstorm correlated with field mill, ground strike location, and weather radar data including the first report of the design and capabilities of a new, time-of-arrival Ground-strike Location System (GSLS)

An experiment designed to observe and measure a thunderstorm prior to, during, and after its development over the Kennedy Space Center was successful. Correlated measurements of airborne field strength, ground-based field strength, LDAR lightning discharge location in the clouds, weather radar percipitation echoes, plus ground strike location with the new KSC Ground Strike Location System (GSLS) were gathered, and reported. This test marks the first operational use of the GSLS System, and this report contains the first report of its design and capabilities.

Poehler, H. A.↗