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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Coordination of Mars Orbiting Assets to Support Entry, Descent, and Landing (EDL) Activities

NASA policy requires continuous telecommunications with missions during the execution of their critical events, which implies constraints on where missions to other planets may land or inject into orbit. JPL is working to establish a telecommunications network at Mars to provide contact with inbound missions to Mars and assets that have landed on the Martian surface, thus reducing the constraints on where critical events may be performed. Coordination of network assets is required to cover an inbound mission's critical event, such as EDL. This paper describes the development of a tool to evaluate EDL coverage capability of Mars network assets over a specified launch date/arrival date space.

Mars Network↗
NASA NTRS2004

Coordination of Mars orbiting assets to support entry, descent, and landing (EDL) activities

NASA policy requires continuous telecommunications with missions during the execution of their critical events, which implies constraints on where missions to other planets may land or inject into orbit. JPL is working to establish a telecommunications network at Mars to provide contact with inbound missions to Mars and assets that have landed on the Martian surface, thus reducing the constraints on where critical events may be performed.

Craig, Lynn↗
NASA NTRS1998

Topography of the northern hemisphere of Mars from the Mars Orbiter Laser Altimeter

The first 18 tracks of laser altimeter data across the northern hemisphere of Mars from the Mars Global Surveyor spacecraft show that the planet at latitudes north of 50 degrees is exceptionally flat; slopes and surface roughness increase toward the equator. The polar layered terrain appears to be a thick ice-rich formation with a non-equilibrium planform indicative of ablation near the periphery. Slope relations suggest that the northern Tharsis province was uplifted in the past. A profile across Ares Vallis channel suggests that the discharge through the channel was much greater than previously estimated. The martian atmosphere shows significant 1-micrometer atmospheric opacities, particularly in low-lying areas such as Valles Marineris.

unmanned↗
NASA NTRS2000

Latest Results from the Mars Orbiter Laser Altimeter (MOLA)

The first MOLA data were acquired in Sept. 1997 shortly after the arrival of Mars Global Surveyor (MGS) at Mars and before the start of aerobraking. Subsequently, data were obtained during several months in the spring and summer of 1998. All these data were obtained over the northern hemisphere. At the beginning of March 1999 the mapping phase of the MGS mission began in the designed 400 km near circular, near polar orbit and MOLA began collecting continuous global data. By the end of 1999 MOLA had acquired over 250 million altimeter measurements of the radius of the planet at accuracies of the order of a few meters radially and about 100 meters horizontally. These observations revealed the detailed structure of the Martian surface, the form of the polar caps, as well as the shape of the planet. The early results provided a unique view of the north polar cap and subsequently of the south polar cap from which an estimate of the total volume of present-day surface water ice of 3.2 to 4.7 million cubic km was obtained. To obtain full coverage of the polar caps it was necessary for MOLA to be pointed off nadir approximately 20 degrees and on several occasions MGS has performed a roll maneuver to make these observations. It is hoped that these off-nadir observations of the central region of the cap (MGS only reaches to latitudes plus or minus 86.5) will assist in the detection of the seasonal deposition of CO2 since it is believed that these high latitudes regions may be the accumulation zone.

Smith, David E.↗
NASA NTRS1972

Radio science experiments - The Viking Mars Orbiter and Lander.

The objective of the radio science investigations is to extract the maximum scientific information from the data provided by the radio and radar systems on the Viking Orbiters and Landers. Unique features of the Viking missions include tracking of the landers on the surface of Mars, dual-frequency S- and X-band tracking data from the orbiters, lander-to-orbiter communications system data, and lander radar data, all of which provide sources of information for a number of scientific investigations. Post-flight analyses will provide both new and improved scientific information on physical and surface properties of Mars, on atmospheric and ionospheric properties of Mars, and on solar system properties.

Michael, W. H., Jr.↗
NASA NTRS2016

The Mars Reconnaissance Orbiter Mission: 10 Years of Exploration from Mars Orbit

The Mars Reconnaissance Orbiter ( MRO ) entered Mars orbit on March 10, 2006. After five months of aerobraking, a series of propulsive maneuvers were used to establish the desired low -altitude science orbit. The spacecraft has been on station in its 255 x 320 k m, sun -synchronous (approximately 3 am -pm ), primary science orbit since September 2006 performing both scientific and Mars programmatic support functions. This paper will provide a summary of the major achievements of the mission to date and the major flight activities planned for the remainder of its third Extended Mission (EM3). Some of the major flight challenges the flight team has faced are also discussed.

MRO↗
NASA NTRS2016

The Mars Reconnaissance Orbiter Mission: 10 Years of Exploration from Mars Orbit

The Mars Reconnaissance Orbiter (MRO) entered Mars orbit on March 10, 2006. After five months of aerobraking, a series of propulsive maneuvers were used to establish the desired low-altitude science orbit. The spacecraft has been on station in its 255 x 320 km, sun-synchronous (~3 am-pm), primary science orbit since September 2006 performing both scientific and Mars programmatic support functions. This paper will provide a summary of the major achievements of the mission to date and the major flight activities planned for the remainder of its third Extended Mission (EM3). Some of the major flight challenges the flight team has faced are also discussed.

MRO↗
NASA NTRS2001

Developing planetary protection technology- microbial diversity of the Mars Orbiter Odyssey and the spacecraft assembly and encapsulation facility II

A study in which several surface samples, retrieved from both the Mars Odyssey Spacecraft and the Kennedy Space Center (KSC) Spacecraft Assembly and Encapsulation Facility II (SAEF-II), were prcesed and evaluated by both molecular and traditional culture-based methods for the microbial diversity.

Odyssey spacecraft microbial assembly facility↗
NASA NTRS1999

Martian Polar Impact Craters: A Preliminary Assessment Using Mars Orbiter Laser Altimeter (MOLA)

Our knowledge of the age of the layered polar deposits and their activity in the volatile cycling and climate history of Mars is based to a large extent on their apparent ages as determined from crater counts. Interpretation of the polar stratigraphy (in terms of climate change) is complicated by reported differences in the ages of the northern and southern layered deposits. The north polar residual ice deposits are thought to be relatively young, based on the reported lack of any fresh impact craters in Viking Orbiter Images. Herkenhoff et al., report no craters at all on the North polar layered deposits or ice cap, and placed an upper bound on the surface age (or, alternatively, the vertical resurfacing rate) of 100 thousand years to 10 million years, suggesting that the north polar region is an active resurfacing site. In contrast, the southern polar region was found to have at least 15 impact craters in the layered deposits and cap. Plaut et al, concluded that the surface was less than or = 120 million years old. This reported age difference factor of 100 to 1000 increases complexity in climate and volatile modeling. Recent MOLA results for the topography of the northern polar cap document a handful or more of possible craters, which could result in revised age or resurfacing estimates for the northern cap. This study is a preliminary look at putative craters in both polar caps. Additional information is contained in the original extended abstract.

Sakimoto, S. E. H.↗
NASA NTRS2001

Mars Global Surveyor Mars Orbiter Camera: Interplanetary Cruise through Primary Mission

More than three years of high-resolution (1.5-20 m/pixel) photographic observations of the surface of Mars have dramatically changed our view of that planet. Among the most important observations and interpretations derived therefrom are that much of Mars, at least to depths of several kilometers, is layered; that substantial portions of the planet have experienced burial and subsequent exhumation; that layered and massive units, many kilometers thick, appear to reflect an ancient period of large-scale erosion and deposition within what are now the ancient heavily cratered regions of Mars; and that processes previously unsuspected, including gully-forming fluid action and burial and exhumation of large tracts of land, have operated within near-contemporary times. These and many other attributes of the planet argue for a complex geology and complicated history.

Malin, Michael C.↗
NASA NTRS2001

Mars Global Surveyor Mars Orbiter Camera: Interplanetary Cruise Through Primary Mission

More than three years of high-resolution (1.5-20 m/pixel) photographic observations of the surface of Mars have dramatically changed our view of that planet. Among the most important observations and interpretations derived are that much of Mars, at least to depths of several kilometers, is layered; that substantial portions of the planet have experienced burial and subsequent exhumation; that layered and massive units, many kilometers thick, appear to reflect an ancient period of large-scale erosion and deposition within what are now the ancient heavily cratered regions of Mars; and that processes previously unsuspected, including gully-forming fluid action and burial and exhumation of large tracts of land, have operated within near-contemporary times. These and many other attributes of the planet argue for a complex geology and complicated history.

Malin, Michael C.↗
NASA NTRS1994

High degree gravitational sensitivity from Mars orbiters for the GMM-1 gravity model

Orbital sensitivity of the gravity field for high degree terms (greater than 30) is analyzed on satellites employed in a Goddard Mars Model GMM-1, complete in spherical harmonics through degree and order 50. The model is obtained from S-band Doppler data on Mariner 9 (M9), Viking Orbiter 1 (VO1), and Viking Orbiter 2 (VO2) spacecraft, which were tracked by the NASA Deep Space Network on seven different highly eccentric orbits. The main sensitivity of the high degree terms is obtained from the VO1 and VO2 low orbits (300 km periapsis altitude), where significant spectral sensitivity is seen for all degrees out through degree 50. The velocity perturbations show a dominant effect at periapsis and significant effects out beyond the semi-latus rectum covering over 180 degrees of the orbital groundtrack for the low altitude orbits. Because of the wideband of periapsis motion covering nearly 180 degrees in w and +39 degrees in latitude coverage, the VO1 300 km periapsis altitude orbit with inclination of 39 degrees gave the dominant sensitivity in the GMM-1 solution for the high degree terms. Although the VO2 low periapsis orbit has a smaller band of periapsis mapping coverage, it strongly complements the VO1 orbit sensitivity for the GMM-1 solution with Doppler tracking coverage over a different inclination of 80 degrees.

Lerch, F. J.↗