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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 163 records · Page 9
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NASA NTRS1984

The PH-D proposal - A manned mission to Phobos and Deimos

The rationale for a manned mission to the satellites of Mars is discussed. The view has been expressed that NASA must define a major program to follow the Shuttle and to utilize it. However, such a program could not be initiated and proceed without public support, and to obtain this support, public interest would have to be excited. It is shown that, of a number of possible targets for manned exploration in the solar system, Mars appears to be the only possible candidate. Attention is given to a comparison of three Mars missions, a Mars 1984 mission, a manned landing on Mars surface, a manned landing on Phobos and Deimos (Ph-D project), putting men in Mars orbit, the capabilities of the Ph-D mission, a description of the spacecraft, a Ph-D project operations plan, and aspects of timing, technology, and costs.

Singer, S. F.↗
NASA NTRS1986

Manned Mars mission transfer from Mars parking orbit to Phobos or Deimos

This paper addresses the problem of orbit transfers from a Mars parking orbit with an inclination of 165 degrees to the Mars moons. The transfer can be accomplished using a three impulse transfer. The current 1999 baseline manned Mars mission requires a Mars parking orbit with an inclination of 165 degrees. This orbit inclination is necessary due to the direction of the Mars arrival and departure asymptotes of the interplanetary trajectory. The selection of this inclination for the parking orbit minimized the delta velocity requirements at Mars arrival and departure. This presents a problem In making transfers from this orbit to either Phobos or Deimos since it is a retrograde orbit. It is possible to make this transfer efficiently using a three impulse transfer and an intermediate transfer orbit with a very large apogee altitude. This paper will show how the intermediate transfer orbit apogee can be determined based on a preselected transfer time, the delta velocities required as a function of transfer time, and the propellant required as a function of mission module weight for a transfer time of 5 days. The data presented in this paper Is specifically for the 1999 opposition class mission but the methods outlined are applicable to any other mission which requires a high inclination parking orbit.

Jack Mulqueen↗
NASA NTRS1988

Phobos and Deimos astrometric observations from Viking

This article describes the reduced astrometric observations of Phobos and Deimos derived from Viking Orbiter 1 and 2 imaging data. This data set spans four years from 1976 to 1980, contains 275 sets of spacecraft-centered, right ascension and declination observations, and has a limiting accuracy of a few km (1 sigma). The details of observation formulation and use for ephemeris improvement are given.

Duxbury, T. C.↗
NASA NTRS1988

Phobos lander coding system: Software and analysis

The software developed for the decoding system used in the telemetry link of the Phobos Lander mission is described. Encoders and decoders are provided to cover the three possible telemetry configurations. The software can be used to decode actual data or to simulate the performance of the telemetry system. The theoretical properties of the codes chosen for this mission are analyzed and discussed.

Cheung, K.-M.↗
NASA NTRS1989

Phobos and Deimos astrometric observations from Mariner 9

This article describes the reduced astrometric observations of Phobos and Deimos derived from Mariner 9 imaging data. This data set spans 11 months from 1971 and 1972, contains 82 sets of spacecraft-centered right ascension and declination observations, and has an accuracy of 3 to 10 km (1-sigma) in orbital position. The details of the observation formulation and its use for ephemeris improvement are given.

Duxbury, T. C.↗
NASA NTRS1989

A robotically constructed production and supply base on Phobos

PHOBIA Corporation is involved with the design of a man-tenable robotically constructed, bootstrap base on Mars' moon, Phobos. This base will be a pit-stop for future manned missions to Mars and beyond and will be a control facility during the robotic construction of a Martian base. An introduction is given to the concepts and the ground rules followed during the design process. Details of a base design and its location are given along with information about some of the subsystems. Since a major purpose of the base is to supply fuel to spacecraft so they can limit their fuel mass, mining and production systems are discussed. Surface support activities such as docks, anchors, and surface transportation systems are detailed. Several power supplies for the base are investigated and include fuel cells and a nuclear reactor. Tasks for the robots are defined along with descriptions of the robots capable of completing the tasks. Finally, failure modes for the entire PHOBIA Corporation design are presented along with an effects analysis and preventative recommendations.

Source record↗
NASA NTRS1990

Martian bow shock - Phobos observations

Data obtained with the Magma magnetometer on the subsolar passes of the Phobos spacecraft during its 3 elliptic orbits reveals a turbulent bow shock with a strong foot consistent with the reflection of solar wind protons. The bow shock lies at a subsolar distance of 1.47 + or - .03 R(M). The circular orbit phase of the mission reveals a bow shock with a highly varying location. The median terminator crossing lies at 2.72 Mars radii. The location of the bow shock in the terminator plane is sensitive to neither the EUV flux nor to planetary longitude.

Schwingenschuh, K.↗
NASA NTRS1991

Picked-up protons near Mars - Phobos observations

The measurements carried out by the plasma spectrometer, Aspera, on board the Phobos-2 spacecraft show that protons, originating in the extended hydrogen corona of Mars, were observed at altitudes not greater than 7500 km. The cyclotron instability of these pickup ions appears to generate Alfven waves observed by the Magma magnetometer. Analysis of the plasma data shows that weak pitch-angle diffusion of a ring-distribution of pickup protons occurs. The altitude profiles of pickup proton fluxes and number densities of the parent hydrogen atoms are derived.

Barabash, S.↗
NASA NTRS1991

On the possible source of the ionization in the nighttime Martian ionosphere. I - Phobos 2 HARP electron spectrometer measurements

The measurements of electron spectra in the Martian magnetosphere by the HARP instrument on board the Phobos 2 orbiter are presented. The energy of the electrons (a few tens of electron volts) is sufficient for the impact ionization of the planetary neutral gas, and the characteristic flux of electrons (about 10 exp 8/sq cm per sec) could produce the nightside ionospheric layer with a peak density of a few thousands of electrons per cubic centimeter, which corresponds to densities observed earlier during radio occultations of the Mars 4 and 5 and Viking 1 and 2 spacecraft. The possibility of magnetospheric electron precipitation into the nightside atmosphere of Mars is in agreement with the mainly induced nature of the magnetic field in the planetary magnetotail (as at Venus), while the variability of the Martian nightside ionosphere may be explained by the partial screening of the atmosphere by a weak intrinsic magnetic field of the planet.

Verigin, M. I.↗
NASA NTRS1992

Analysis of Phobos mission gamma ray spectra from Mars

The determination of the elemental composition of the surface of a planetary body can be achieved, in many cases, by remote-sensing gamma ray spectroscopy. A gamma ray spectrometer was carried on the Soviet spacecraft Phobos-2, and obtained data while in an elliptical orbit around Mars. Results of two independent approaches to data analysis, one by the Soviet group and one by an American group are reported. The results for five elements are given for two different orbits of Mars. Major geologic units that contribute to the signal for each orbit have been identified. The results from the two techniques are in general agreement and there appear to be no geologically significant differences between the results for each orbit.

Trombka, J. I.↗
NASA NTRS1992

Phobos and Deimos are sources of meteoroids

Data of Pioneer 10 meteoroid penetration detectors were revised taking into account the orientation of detectors and the spacecraft velocity relative to the sporadic meteor flux. The meteor flux density increases as an exponent to the orbit of Mars for two times for the particles with masses greater than 10(exp -6) g and six times for the particles with masses greater than 10(exp -12) - 10(exp -9) g then decreases after the orbit. Ejections of secondary meteoroid particles from surfaces of Phobos and Deimos are a possible explanation for the increase in meteoroid flux.

Andreev, V. V.↗
NASA NTRS1990

Spacecraft studies of Phobos and Mars

Utilizing the Termoskan data set of the Phobos '88 mission we have recognized a new feature on Mars: Ejecta blanket Distinct In the THermal infrared (EDITH). Virtually all of the more than one hundred of these features discovered in the Termoskan data are located on the plains near Valles Manneris. EDITH's have a startlingly clear dependence upon terrains of Hesperian age, implying a spatial or temporal dependence on Hesperian terrains. Almost no thermally distinct ejecta blankets are associated with any of the thousands of craters within the data set that occur on the older Noachian units. EDITH's also do not appear on the portions of the younger Tharsis Amazonian units seen in the data. The Hesperian terrain dependence cannot be explained by either atmospheric or impactor variations; Noachian and Hesperian terrains must have experienced identical atmospheric and impactor conditions during Hesperian times. Thermally distinct eject a blankets therefore reflect target material differences and/or secondary modification processes. A further discussion of EIDTH's is presented.

Murray, Bruce C.↗
NASA NTRS1989

Design of a direct nuclear propulsion system for a resupply mission to Phobos

For a long-term mission in space, a propulsion system with a high specific impulse and low mass must be designed. The system must also be safe in terms of human lives and must be cost efficient to a degree. The main focus is to design a direct nuclear propulsion system for a resupply mission to Phobos from an orbiting Earth space station and return. The design considered is an annular, packed particle bed nuclear reactor with hydrogen used as the reflector, moderator, coolant, and propellant. The use of hydrogen in all these areas helps reduce the total mass, since the amount of hydrogen required is only that needed for propulsion. The mass of hydrogen required for propulsion is reduced by using a direct nuclear propulsion system with a high specific impulse relative to a hydrogen oxygen system. Certain calculations were not looked at in great detail. This included the aerospace details of the mission. Most of the numbers for this section were found in tables and taken to be correct without extensive calculations. The main objective of the project was to study the thermohydraulic and neutronic aspects of the reactor.

Frymire, R.↗
NASA NTRS1993

A comparison of telescopic and Phobos-2 ISM spectra of Mars in the short-wave near-infrared (0.76-1.02 microns)

Recent analyses of near-IR (0.76-3.16 microns) Mars surface reflectance spectra obtained by the Phobos-2 ISM instrument during early 1989 have revealed the presence of substantial variability in surface spectral properties. Strong absorption features seen in the 0.85-1.05 micron region are up to 10-15 percent deep relative to the local continuum and have been interpreted as evidence of Fe(2+) and Fe(3+) bearing minerals (pyroxenes and iron oxides, respectively). Though these observed band depths are comparable to those seen in laboratory reflectance spectra, they are up to three times larger than most previously reported band depths for Mars spectra at these wavelengths. Six regions of variable albedo and geologic setting were identified where ISM and 1988 opposition telescopic coverage either overlapped physically or sampled the same surface geologic unit. The areal sizes and positions of the regions measured telescopically were compiled by Bell et al. ISM pixels falling within these spots were averaged to produce a spatially convolved spectrum that simulates what would have been seen telescopically. To facilitate comparisons of absorption band positions and relative strengths, the convolved ISM data and the 1988 telescopic spectra were scaled to unity at 0.81 microns and are presented. The data have also been convolved to equivalent band pass normalized reflectances in the region of spectral overlap. A scatter diagram of telescopic vs. ISM reflectances is shown. The results from the investigation are discussed.

Bell, James F., III↗
NASA NTRS1992

Interdisciplinary scientist participation in the Phobos mission

Data was acquired from VSK (2 wide-angle visible-NIR TV cameras at 0.4 to 0.6 micrometers and 0.8 to 1.1 micrometers, and a narrow-angle TV camera), KRFM (10-band UV-visible spectrometer at 0.3 to 0.6 micrometers and a 6-band radiometer at 5-50 micrometers), and ISM (a 128-channel NIR imaging spectrometer at 0.8 to 3 micrometers). These data provided improved mapping coverage of Phobos; improved mass, shape, and volume determinations, with the density shown to be lower than that of all known meteorites, suggesting a porous interior; evidence for a physically, spectrally and possibly compositionally heterogeneous surface; and proof that the spectral properties do not closely resemble those of unaltered carbonaceous chondrites, but show more resemblance to the spectra of altered mafic material. For Mars, the data show that the underlying rock type can be distinguished through the global dust cover; that the spectral properties and possibly composition vary laterally between and within the geologic provinces; that the surface physical properties vary laterally, and in many cases, the boundaries coincide with those of the geologic units; and the acquired data also demonstrate the value of reflectance spectroscopy and radiometry to the study of Martian geology.

Source record↗
NASA NTRS1993

A robotic exploration mission to Mars and Phobos

This report discusses the design of a robotic exploration to Mars and Phobos. It begins with the mission's background and objectives, followed by a detailed explanation of various elements of Project Aeneas, including science, spacecraft, probes, and orbital trajectories. In addition, a description of Argos Space Endeavours, management procedures, and overall project costs are presented. Finally, a list of recommendations for future design activity is included.

Kerr, Justin H.↗
NASA NTRS1994

Evidence for komatiite-type lavas on Mars from Phobos ISM data and other observations

Data from the Phobos 2 Imaging Spectrometer for Mars (ISM), compiled by Mustard et al. (1993), and other observations support the existence of komatiitic lavas on Mars. Mustard et al. (1993) determined from ISM data that the composition of the low-albedo materials covering the Syrtis Major plateau originally consisted of augite-bearing basalt containing both augite and pigeonite, with no appreciable amount of olivine. This description is consistent with a komatiitic basalt. Komatiite is significant for the Earth because it contains a high amount of MgO, implying generation under unique circumstances compared to more typical basaltic compositions and may be similarly important for Mars.

Reyes, David P.↗
NASA NTRS1994

The flaring of the Martian magnetotail observed by the Phobos 2 spacecraft

Spacecraft observations from the Earth's magnetotail show that the flaring angle depends on the downtail distance, the upstream solar wind dynamic pressure and the B(sub z) component of the interplanetary magnetic field (1993). Measurements from the Phobos 2 spacecraft along a circular orbit at 2.8 Mars radii allow a similar study of the Mars magnetotail. Under the assumption that the magnetic pressure in the Martian tail lobes is much greater than the plasma pressure in the lobe, we use the pressure balance condition between the tail lobe magnetic pressure and the normal component of the solar wind pressure to infer the angle at which the tail magnetopause flares. As in the case of the terrestrial magnetotail, the flaring angle of Mars tail depends on the solar wind dynamic pressure, but this angle (at 2.5 R(sub M)) is about one half of the terrestrial value (at 17 R(sub E)). The median inferred flaring angle is about 13 deg.

Zhang, T.-L.↗