Search NASA⌕ Search

SEARCH · Search NASA

Results for “LONG RANGE”

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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Long range planning for the development of space flight emergency systems.

The importance of long-range planning for space flight emergency systems is pointed out. Factors in emergency systems planning are considered, giving attention to some of the mission classes which have to be taken into account. Examples of the hazards in space flight include fire, decompression, mechanical structure failures, radiation, collision, and meteoroid penetration. The criteria for rescue vehicles are examined together with aspects regarding the conduction of rescue missions. Future space flight programs are discussed, taking into consideration low earth orbit space stations, geosynchronous orbit space stations, lunar operations, manned planetary missions, future space flight vehicles, the space shuttle, special purpose space vehicles, and a reusable nuclear shuttle.

Bolger, P. H.↗
NASA NTRS1985

The effects of grain size on the flow and fracture of long-range ordered alloys

The effects of grain size on the mechanical properties of long-range ordered alloys are examined with reference to the short-term behavior of aluminide intermetallics. It is shown that in those L1(2) alloys which exhibit anomalous thermal strengthening, the grain size affects the magnitude of the strengthening. In some cases it also affects ductility, whereby the tensile elongation and the tensile strength increase as the grain size decreases below a critical point. It is also believed that grain size may affect the partitioning of microalloying elements, such as boron, in Ni3Al.

Schulson, E. M.↗
NASA NTRS1967

Long-range interatomic forces.

Quadrupole-quadrupole interaction constant for Se and halogen diatomic molecules, discussing long range interatomic forces determination

Chang, T. Y.↗
NASA NTRS1994

A criterion autoscheduler for long range planning

A constraint-based scheduling system called SPIKE is used to create long-term schedules for the Hubble Space Telescope. A meta-level scheduler called the Criterion Autoscheduler for Long range planning (CASL) was created to guide SPIKE's schedule generation according to the agenda of the planning scientists. It is proposed that sufficient flexibility exists in a schedule to allow high level planning heuristics to be applied without adversely affected crucial constraints such as spacecraft efficiency. This hypothesis is supported by test data which is described.

Sponsler, Jeffrey L.↗
NASA NTRS1972

Studies for determining the optimum propulsion system characteristics for use in a long range transport aircraft

A comprehensive evaluation of propulsion systems for the next generation of near-sonic long range transport aircraft indicates that socially responsive noise and emission goals can be achieved within the probable limits of acceptable airplane performance and economics. Technology advances needed in the 1975-1985 time period to support the development of these propulsion systems are identified and discussed. The single most significant result is the low noise, high performance potential of a low tip speed, spaced, two-stage fan.

Brines, G. L.↗
NASA NTRS1973

Study of unconventional propulsion system concepts for use in a long range transport

The noise level of an uncoventional propulsion system for the next generation of subsonic, long-range transport aircraft is discussed. The desired noise level may be achieved by: (1) a fixed geometry, high bypass ratio turbofan with a geared two-stage fan and advanced acoustic treatment or (2) a moderate bypass ratio turbofan with a variable pitch two-stage fan, variable primary and duct nozzles, and advanced acoustic treatment. The geared fan system meets the noise goal with minimum economic penalty. Comparison of the noise levels at takeoff and landing in combination with the economic penalties required to achieve the lower noise levels at specific noise measuring stations, indicate that both area reduction and current certification prodedures should be used to ascertain the point of diminishing returns in establishing future noise goals.

Champagne, G. A.↗
NASA NTRS1978

Largo hot water system long range thermal performance test report, addendum

The test procedure used and the test results obtained during the long range thermal performance tests of the LARGO Solar Hot Water System under natural environmental conditions are presented. Objectives of these tests were to determine the amount of energy collected, the amount of power required for system operation, system efficiency, temperature distribution, and system performance degradation.

Source record↗
NASA NTRS2006

The Effects of Ultra-Long-Range Flights on the Alertness and Performance of Aviators

This investigation assessed the impact of ultra-long-range (ULR) simulator flights, departing either in the morning or late evening, on the alertness and performance of 17 commercial aviators. Immediately prior to and throughout each flight, alertness and performance were assessed via a computerized test of sustained attention, subjective questionnaires, and "hand-flying" tasks. There were fatigue-related effects on the majority of assessments, and the nature of these effects was consistent across the vigilance and self-report measures. However, the operational "hand-flying" manuevers proved insensitive to the impact of fatigue probably due to procedural factors. Regardless, the results of the present study suggest that fatigue associated with prolonged wakefulness in ULR flight operations will interact with flight schedules due to circadian and homeostatic influences. In this study, the pilots departing at night were at a greater initial disadvantage (during cruise) than pilots who departed earlier in the day; whereas those who departed earlier tended to be most impaired towards the end of the flight prior to landing. In real-world operations, airlines should consider the ramifications of flight schedules and what is known about human sleep and circadian rhythms to optimize safety.

Caldwell, John A.↗
DOE OSTI2026

Observation of Long-Range Collective Flow in O + O and Ne + Ne Collisions and Implications for Nuclear Structure Studies

The long-range collective flow of particles produced in oxygen-oxygen ( O + O ) and neon-neon ( Ne + Ne ) collisions is measured with the CMS detector at the CERN LHC. The data samples were collected at a center-of-mass energy per nucleon pair of 5.36 TeV, with integrated luminosities of 7 nb - 1 and 0.8 nb - 1 for O + O and Ne + Ne collisions, respectively. Two- and four-particle azimuthal correlations are measured over nearly five units of pseudorapidity. Significant elliptic ( v 2 ) and triangular ( v 3 ) flow harmonics are observed in both systems. The ratios of v n coefficients between Ne + Ne and O + O collisions suggest sensitivity to the intrinsic nuclear structure of the respective Ne and O ions. Hydrodynamic models with ab initio nuclear structure inputs qualitatively reproduce the collision-overlap dependence of both the v n values and the Ne + Ne to O + O ratios. These measurements provide new constraints when modeling the interplay of nuclear structure and collective dynamics in collisions of O 16 and Ne 20 ions, respectively.

Hayrapetyan, Aram [Yerevan Phys. Inst.]↗