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Soffen, G. A.

Publications and source records attributed to Soffen, G. A..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

What should we look for when we return to Mars?

The current state of knowledge about Mars is examined, and the details of current planned missions (Phobos and the Mars Orbiter) are considered. Speculations on some of the major future avenues of Mars research are presented; particular attention is given to questions relating to the early geological processes that resulted in Martian surface features, the effect liquid water has had on the planet, the volatile dynamics and chemistry, the chemistry of the iron-rich clays, the organic-compound mystery, and the biological issue.

Soffen, G. A.↗
NASA NTRS1983

Pioneering in gravitational physiology

Gravity affects biology at almost all levels above that of the cell organelle. Attention is presently given to progress made in the understanding of gravitational effects through studies employing centrifuges, clinostats, inverted preparations, linear devices, water immersion, free fall, and short- and long-term spaceflight. The cardiovascular changes which cause malaise and illness during the first few days of extended space missions are the direct result of fluid translocation from the lower extremities. Upon reentry, there is hypovolumnia and a cardiovascular deconditioning that can include tachycardia, changes in arterial blood pressure, narrow pulse pressure, and syncope. Attention is also given to NASA's gravitational physiology reseach program.

Soffen, G. A.↗
NASA NTRS1981

Life on Mars

The Viking biology experiments are examined. It is noted that the Viking missions did not find a terrestrial type of life at either of the two landing sites. This evidence may suggest that Mars is lifeless, but science demands a more rigorous proof; thus, it is still not known whether life exists on Mars. It is suggested that the Martian polar regions must be explored before a conclusive answer is possible; the permanent polar caps of Mars are frozen water and would act as a 'cold finger' of the planet to trap organic molecules.

Soffen, G. A.↗
NASA NTRS1978

Mars and the remarkable Viking results

It is pointed out that the Viking missions to Mars are the most extraordinary and complex remote effort ever performed by man. Factors which made the Viking results so remarkable are related to the technological engineering accomplishment, the voluminous scientific data about the planet, and the public interest. Quite surprisingly it was found that the Viking 1 landing site was very similar to the California desert. Attention is given to details of spacecraft landing on the Martian surface, aspects of landing site selection, the design and the operation of Lander instruments, the nine different investigations performed by the Lander, the significance of the pictures obtained of Mars, the remarkable heterogeneity of the planet, the extent and variety of volcanism, the presence of water in the solid and gaseous form on the Martian surface, the presence of water in the liquid phase at some time in the past, the two natural Martian satellites, the composition of the Martian polar caps and their changes during the seasons, the composition of the atmosphere, and the biological results, which remain ambiguous.

Soffen, G. A.↗
NASA NTRS1977

The Viking project

The Viking project launched two unmanned spacecraft to Mars in 1975 for scientific exploration with special emphasis on the search for life. Each spacecraft consisted of an orbiter and a lander. The landing sites were finally selected after the spacecraft were in orbit. Thirteen investigations were performed: three mapping experiments from the orbiter, one atmospheric investigation during the lander entry phase, eight experiments on the surface of the planet, and one using the spacecraft radio and radar systems. The experiments on the surface dealt principally with biology, chemistry, geology, and meteorology. Seventy-eight scientists have participated in the 13 teams performing these experiments. This paper is a summary of the project and an introduction to the articles that follow.

Soffen, G. A.↗
NASA NTRS1976

Scientific results of the Viking missions

The two Viking missions to Mars have been extraordinarily successful. Thirteen scientific investigations yielded information about the atmosphere and surface. Two orbiters and landers operating for several months photographed the surface extensively from 1500 kilometers and directly on the surface. Measurements were made of the atmospheric composition, the surface elemental abundance, the atmospheric water vapor, temperature of the surface, and meteorological conditions; direct tests were made for organic material and living organisms. The question of life on Mars remains unanswered. The Viking spacecraft are designed to continue the investigations for at least one Mars year.

Soffen, G. A.↗
NASA NTRS1976

Status of the Viking missions

A chronology of Viking 1 lander activities is presented for the first 43 sols (Martian days) of surface sampling and analysis. The orbital insertion of the second Viking spacecraft is reviewed along with the search for the second landing site. A general assessment of the planet is made on the basis of the data thus far obtained. Some of the findings reported are that: (1) there is extensive evidence of volcanism, fluvial and aeolian erosion, and deposition over the entire surface; (2) the floor of Vallis Marineris is significantly younger than the planet's surface; (3) the morphology of Martian crater ejecta is indicative of surface flow rather than ballistic deposition; (4) the rocks in the immediate vicinity of the lander are all covered by a layer of fine red dust; (5) the atmosphere is optically thick and well mixed, with suspended particles giving the sky a pink color; (6) the N and Ar isotopic ratios are different from those on earth; (7) atmospheric water vapor varies with both time of day and location; (8) the summer northern polar regions have a high water concentration in the atmosphere; (9) a large fraction of magnetic material resides in the surface; and (10) no complex organic compounds have been detected in the two samples analyzed.

Soffen, G. A.↗
NASA NTRS1976

The first Viking mission to Mars

The paper outlines the major goals and present achievements of the Viking 1 mission to Mars. The construction and instrumentation of the orbiter and lander are described. The criteria used to select the optimum landing site are discussed together with orbit adjustments and the landing process. Special attention is given to constraints on surface coverage and observation conditions.

Soffen, G. A.↗
NASA NTRS1976

The voyages of Viking. I - Why explore

The possible significance of data on the environment of Mars obtained by the Viking Mars lander is discussed. Such data may provide the basis for a comparative study of the chemical evolution of the earth and Mars. The implications of the presence or absence of evidence of life on Mars for the probability of life in similar solar systems are considered.

Soffen, G. A.↗
NASA NTRS1974

The science of the Viking missions

The Viking missions involve the launching of two identical spacecraft in the summer of 1975. Each spacecraft consists of a Lander and an Orbiter combination. The initial deceleration of the Lander during its descent to the Martian surface will be caused by aerodynamic drag. At about 5 km above the surface, a parachute is deployed. At 2 km three retrorockets are fired. The investigations to be conducted are discussed, giving attention to studies of the Martian surface with the aid of TV cameras, water mapping with an IR spectrometer, a thermal mapping experiment, studies of the Martian atmosphere, investigations conducted with a surface sampler, the search for life, and studies of the Martian surface composition.

Soffen, G. A.↗
NASA NTRS1973

The Viking Mission

The Viking Mission is a scientific exploration of the planet Mars with particular emphasis on the search for life. Two unmanned spacecraft will be launched from Cape Kennedy in 1975 and will arrive at Mars in the summer of 1976. Each spacecraft will consist of an orbiter and lander. The landing sites will be preselected before launch and certified by orbital reconnaissance before landing. Soft landing on the surface will be accomplished by decelerating first on an aeroshell, then a deployed parachute and finally using terminal propulsion engines. Thirteen investigations will be performed, including mapping experiments from the orbiter, and analytical experiments on the surface which deal broadly with the biology, geosciences and atmospheric characteristics of the planet.

Martin, J. S., Jr.↗
NASA NTRS1972

The Viking missions to Mars.

The Viking Project will launch two unmanned spacecraft to Mars in 1975 for scientific exploration with special emphasis on the search for life. Each spacecraft will consist of an orbiter and a lander. The landing site will be selected after the spacecraft is in orbit. Twelve investigations will be performed: three mapping experiments from the orbiter, one atmospheric experiment during the lander entry phase, seven analytical experiments on the surface of the planet, and one using the spacecraft radio and radar systems. The experiments on the surface will deal principally with biology, geology, and meteorology. Sixty-three scientists have been selected for the twelve teams.

Soffen, G. A.↗
NASA NTRS1971

The Viking mission to Mars.

In 1975 the National Aeronautics and Space Administration will launch two unmanned scientific payloads to make soft landings on Mars in 1976. They will be placed in orbit around the planet to perform a reconnaissance before landing. The spacecraft will be separated into an orbiter, which is sent to the surface. During the entry into the Martian atmosphere, Viking will make measurements of the composition and atmospheric structure. After landing, two cameras will be used to visually characterize the site. A device will be deployed to obtain a sample of the Mars surface, which will be returned to the lander for biological tests and for chemical analysis. The atmosphere at the surface will be chemically analyzed as well as the wind velocity, the humidity, and changes in temperature and pressure.

Soffen, G. A.↗
NASA NTRS1969

Extraterrestrial optical microscopy.

Extraterrestrial optical microscopy, discussing experiment, telemetry, data interpretation and instrument characteristics concerning biological, cytochemical and petrographic microscopes

Soffen, G. A.↗
NASA NTRS1966

Apparatus enables automatic microanalysis of body fluids

Apparatus will automatically and quantitatively determine body fluid constituents which are amenable to analysis by fluorometry or colorimetry. The results of the tests are displayed as percentages of full scale deflection on a strip-chart recorder. The apparatus can also be adapted for microanalysis of various other fluids.

Soffen, G. A.↗