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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 325 records · Page 18
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Limitations of terrestrial life.

Questions of the suitability of other planets in the solar system for terrestrial organisms are discussed. It is found that life forms similar to terrestrial organisms but modified to fit the prevailing conditions could exist on Venus, Mars, and Jupiter. Of these, only in the case of Jupiter is there any evidence that life would have been able to evolve. Life on Jupiter would be restricted to the clouds. It is pointed out that life may have developed on other celestial bodies in forms which are quite dissimilar to terrestrial organisms with regard to their biochemistry.

Molton, P.↗
NASA NTRS1972

The Mariner Mars 1971 orbiter.

The Mariner Mars 1971 (MM '71) orbiter spacecraft, launched toward Mars in the spring of 1971, was designed to offer the first opportunity for sustained observations in the near vicinity of another planet of our solar system. The MM '71 spacecraft, like its predecessors, is fully attitude stabilized about three axes, using the sun and Canopus as references, an orientation which allows use of photovoltaic solar panels for primary power and permits two-way communication to the earth through a high-gain directional antenna. Midcourse and orbit insertion maneuvers use the sun-Canopus orientation as a reference direction for initiating commanded turns. Scientific instruments employed during Mars orbital operations are mounted on a two-degree-of-freedom platform controlled by commands from the central computer and sequencer. Science measurements to be obtained by the MM '71 spacecraft include television visual imaging, infrared radiometry, infrared spectroscopy, ultraviolet spectroscopy, S-band radio occultation, and celestial mechanics.

Scull, J. R.↗
NASA NTRS1973

Landmark navigation and topographical mapping.

Proposed new navigational and mapping techniques could be of interest when using unmanned vehicles in the exploration of planets within the solar system. Recently developed techniques make use of landmarks whose coordinates are unknown but within sight of the surface vehicle. The techniques described in the present paper still make use of landmarks whose positions are unknown; however, they offer the added features of (1) travel and mapping beyond the original landmarks by discarding them and choosing new ones, (2) the determination of ranges relative to a selected range at the original starting point, (3) the determination of the direction back to the original starting point or any other previously travelled point, and (4) travel and mapping regardless of whether an angle reference is available.

Bennett, J. E.↗
NASA NTRS1972

Planets and satellites: A survey of fundamental facts

An account of the fundamental properties of the planets of the solar system and of their satellites including their masses, dimensions and distances is presented. The observational uncertainty in present knowledge of planetary masses and dimensions (or mean densities) is discussed critically. The fact is pointed out that the initial scale of the solar system may have differed appreciably from the present one. Observed phenomena which can furnish empirical information on the internal structure of the planetary globes will also be reviewed.

Kopal, Z.↗
NASA NTRS1973

Discourse following award of Kepler Gold Medal

Kuiper briefly reviews Kepler's contributions to the field of planetary astronomy and physics, along with references to his own background in the study of stars, planets, and the solar system. He mentions his participation in NASA programs related to planetary astronomy. He concludes his remarks with thanks for being honored by the award of the Kepler Gold Medal.

Kuiper, G. P.↗
NASA NTRS1974

The Deep Space Network

The objectives, functions, and organization, of the Deep Space Network are summarized. Deep Space stations, ground communications, and network operations control capabilities are described. The network is designed for two-way communications with unmanned spacecraft traveling approximately 1600 km from earth to the farthest planets in the solar system. It has provided tracking and data acquisition support for the following projects: Ranger, Surveyor, Mariner, Pioneer, Apollo, Helios, Viking, and the Lunar Orbiter.

Source record↗
NASA NTRS1974

Scientific objectives of space exploration

One of the objectives of space exploration is the study of the properties of the interplanetary and the interstellar medium. The second objective is concerned with the exploration of the moon and the other planets in the solar system. A third objective involves the investigation of stellar and galactic characteristics and phenomena. An outline of the results obtained with regard to the three objectives of space exploration is presented together with plans for future space-related studies.

Mark, H.↗
NASA NTRS1975

Long-range communications with Pioneer 10 at Jupiter

The longest two-way telecommunications link ever established connected Pioneer 10 with its controllers and experimenters on earth during the first Jovian encounter. This radio link, operating in the 2.1 and 2.3 gigahertz frequency bands, maintained high-quality communications over a distance of 5-1/2 astronomical units. The data collected by eleven on-board advanced scientific instruments were transmitted to the investigators, providing a new wealth of information about the largest planet of the solar system. A descriptive review is presented of the spacecraft design and the ground data system configuration with an analysis of the telecommunications downlink. Pioneer 10, aided by Jupiter's gravitational field, is the first spacecraft to leave the solar system. A plaque attached to the spacecraft represents man's first attempt to send a message to another intelligence within our galaxy.

Dickerson, L. W.↗
NASA NTRS1976

A history of the deep space network

The Deep Space Network (DSN) has been managed and operated by the Jet Propulsion Laboratory (JPL) under NASA contract ever since NASA was formed in late 1958. The Tracking and data acquisition tasks of the DSN are markedly different from those of the other NASA network, STDN. STDN, which is an amalgamation of the satellite tracking network (STADAN) and the Manned Space Flight Network (MSFN), is primarily concerned with supporting manned and unmanned earth satellites. In contrast, the DSN deals with spacecraft that are thousands to hundreds of millions of miles away. The radio signals from these distant craft are many orders of magnitude weaker than those from nearby satellites. Distance also makes precise radio location more difficult; and accurate trajectory data are vital to deep space navigation in the vicinities of the other planets of the solar system. In addition to tracking spacecraft and acquiring data from them, the DSN is required to transmit many thousands of commands to control the sophisticated planetary probes and interplanetary monitoring stations. To meet these demanding requirements, the DSN has been compelled to be in the forefront of technology.

Corliss, W. R.↗
NASA NTRS1977

Until the sun dies

This book gives a popular account of the forces that have shaped human beings into their present form and created the power of human intelligence, and considers the prospects for intelligent life on other planets in the solar system and elsewhere in the universe. The chain of events leading from the big bang to the origin of life on earth is reviewed together with the observations that established the expansion of the universe. Philosophical difficulties with the concept of a universe that has both a beginning and an end are pondered, steady-state cosmology is briefly explained, and the discovery of the relict microwave background is discussed. The formation of the solar system is recounted along with the scientific view of the origin of terrestrial life. Attention is given to the origin of cells and the evolution of oxygen-breathing life, multicelled creatures, armored animals, fishes, amphibians, early reptiles, dinosaurs, and mammals. The development of mammalian intelligence is traced from the early tree dwellers through monkeys, apes, ape men, humanoid tool makers, and primitive members of the genus Homo, to Homo sapiens. Possible evidence for the existence of life on Mars is evaluated together with prospects for communication or other contact with extraterrestrial intelligence.

Jastrow, R.↗
NASA NTRS1978

Direct imaging of extra-solar planets with stationary occultations viewed by a space telescope

The use of a telescope in space to detect planets outside the solar system by means of imaging at optical wavelengths is discussed. If the 'black' limb of the moon is utilized as an occulting edge, a hypothetical Jupiter-Sun system could be detected at a distance as great as 10 pc, and a signal-to-noise ratio of 9 could be achieved in less than 20 min with a 2.4 m telescope in space. An orbit for the telescope is proposed; this orbit could achieve a stationary lunar occultation of any star for a period of nearly two hours.

Elliot, J. L.↗
NASA NTRS1978

Aerospace highlights and potential medical applications

An attempt is made to provide an overview of activities going on in NASA from aeronautics to manned space flight, to exploration of other planets. Some of the spin-offs of NASA research related to the medical profession are described. The discussion focuses on the Space Shuttle, the unmanned spacecraft Seasat program, the exploration of other planets in the solar system, a water-cooled helmet, and some breakthroughs in medical diagnostic instrumentation.

Syvertson, C. A.↗
NASA NTRS1979

Efficiency optimization of a thermionic converter array

Intensive study of the outer planets of the solar system requires the use of nuclear power for electric propulsion of spacecraft. Among the power conversion devices being considered for this application are thermionic converters. This paper presents the results of computer modeling of thermionic converters to identify the major design variables and select an optimum size for each of the thermionic converters for the power conversion system under consideration. Among the variables investigated were electrical and thermal losses in electrodes, leads and heat chokes. Those elements which minimized the electrical losses tended to increase thermal losses and system weight. Overall mechanical design and relative positioning of components also had impacts on converter efficiency and the power subsystem weight. Numerical calculations were made using the computer heat transfer code SINDA coupled with electrical loss parameters. The results of the computations are presented in this paper.

Kuo, Y. S.↗
NASA NTRS1985

Galileo

The Galileo consists of two main parts: a Jupiter orbiter and a probe. After a 1000 day journey, the Galileo will assume orbit around the giant planet, an orbit which will last for 200 days, in the hopes of astronomers. The orbit will carry the Galileo past its four Jovian satellites--Io, Europa, Ganymede, and Callisto - a combined total of 11 times. This will enable scientists to study the atmosphere of not only the largest planet in the solar system, but its large moons as well. Sometime in August of 1988, the Galileo will approach Jupiter and begin its important activities. Fifty-six days away from planetary encounter, the Galileo will release the probe which will continue the trip to Jupiter and enter the atmosphere. As it descends through the atmosphere, the probe will unfurl a parachute to slow its speed as it broadcasts information back to the waiting orbiter, which will in turn relay it back to the waiting scientists on Earth. The probe's descent time is expected to be approximately 15 min before Jupiter's pressure and heat overwhelm the probe's protection. However, scientists are hopeful that the probe will survive longer than 15 min, possibly up to 60 min.

Hwang, C.↗
NASA NTRS1984

Future observations of planetary rings from groundbased observatories and earth-orbiting satellites

Three of the outer planets of our solar system are known to possess ring systems and, among the three known systems, all have one or more components that are detectable from the vicinity of the earth. Among the more promising methods for continuing study are direct imaging and occultations, obtainable both from the ground and from earth-orbiting facilities such as Space Telescope. Relevant future observations made from the vicinity of earth are expected to provide new knowledge of the dynamical and photometric properties of these outer solar system planetary rings.

Smith, B. A.↗
NASA NTRS1986

Rare and unique meteorites from Antarctica

The detection of Antarctic meteorites of Lunar and perhaps Martian origin, belongs to the most important discoveries in planetology during the last years. There is such a wealth of new information on differentiated and undifferentiated planetary bodies deduced from Antarctic meteorites that it is at present not possible to even qualitatively foresee the impact that these meteorites will have on the understanding of the formation and differentiation of large and small planets in the solar system. Martian meteorites, Lunar meteorites, meteorites from the parent body of basaltic achondrites, and chrondritic meteorites are discussed.

Palme, H.↗
NASA NTRS1986

Galileo - Responses to the Challenger accident

The Galileo mission to Jupiter will make the first direct sampling of the atmosphere of the solar system's largest planet and will spend as long as 22 months orbiting Jupiter. Launch date, trajectory, Jupiter arrival, and number of orbits of that planet depend on NASA's flight schedules since destruction of the Space Shuttle Challenger on Jan. 28, 1986. Galileo's responses to the schedule changes caused by the Challenger explosion are discussed.

Casani, John R.↗
NASA NTRS1986

Is there a single origin of life?

The emergence of the first life on the earth is now established as an early event, closely related to the evolving earth. Lack of knowledge of the primitive terrestrial conditions contemporary with the evolving prebolic organic chemistry limits reconstruction techniques. The primitive earth's aqueous history is essential to unraveling this problem. Based on current knowledge of other planets of the solar system, no close analog to the early earth can be expected. It is still not known if there was a second origin or if only earth has life. This may depend upon the question of the survival of information-bearing chemical systems in a dynamic or chaotic environment and the chemical protection afforded within such a system. Water is the central molecule of controversy: the blessing and the curse of the chemist. New and novel chemical mechanisms and systems abound.

Soffen, Gerald A.↗