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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 NTRS2005

Neptune Polar Orbiter with Probes

The giant planets of the outer solar system divide into two distinct classes: the gas giants Jupiter and Saturn, which consist mainly of hydrogen and helium; and the ice giants Uranus and Neptune, which are believed to contain significant amounts of the heavier elements oxygen, nitrogen, and carbon and sulfur. Detailed comparisons of the internal structures and compositions of the gas giants with those of the ice giants will yield valuable insights into the processes that formed the solar system and, perhaps, other planetary systems. By 2012, Galileo, Cassini and possibly a Jupiter Orbiter mission with microwave radiometers, Juno, in the New Frontiers program, will have yielded significant information on the chemical and physical properties of Jupiter and Saturn. A Neptune Orbiter with Probes (NOP) mission would deliver the corresponding key data for an ice giant planet. Such a mission would ideally study the deep Neptune atmosphere to pressures approaching and possibly exceeding 1000 bars, as well as the rings, Triton, Nereid, and Neptune s other icy satellites. A potential source of power would be nuclear electric propulsion (NEP). Such an ambitious mission requires that a number of technical issues be investigated, however, including: (1) atmospheric entry probe thermal protection system (TPS) design, (2) probe structural design including seals, windows, penetrations and pressure vessel, (3) digital, RF subsystem, and overall communication link design for long term operation in the very extreme environment of Neptune's deep atmosphere, (4) trajectory design allowing probe release on a trajectory to impact Neptune while allowing the spacecraft to achieve a polar orbit of Neptune, (5) and finally the suite of science instruments enabled by the probe technology to explore the depths of the Neptune atmosphere. Another driving factor in the design of the Orbiter and Probes is the necessity to maintain a fully operational flight system during the lengthy transit time from launch through Neptune encounter, and throughout the mission. Following our response to the recent NASA Research Announcement (NRA) for Space Science Vision Missions for mission studies by NASA for implementation in the 2013 or later time frame, our team has been selected to explore the feasibility of such a Neptune mission.

Bienstock, Bernard↗
NASA NTRS1973

System design of the Pioneer Venus spacecraft. Volume 1: Executive summary

The NASA Ames Research Center Pioneer Venus Project objective is to conduct scientific investigations of the planet Venus using spin stabilized spacecraft. The defined approach to accomplish this goal is to implement a multiprobe spacecraft mission and an orbiter spacecraft mission. Candidate launch vehicles for the Pioneer Venus missions were the Thor/Delta and Atlas/Centaur. The multiprobe spacecraft consists of a probe bus, one large probe, and three small probes. The probes are designed to survive to the surface of Venus, and to make in situ measurements of the Venusian atmosphere; the probe bus enters the atmosphere and makes scientific measurements until it burns out. The orbiter mission uses a spacecraft designed to orbit Venus for 225 days with an orbit period of about 24 hours (h). The probe bus and orbiter designs are to use a common spacecraft bus.

Dorfman, S. D.↗
NASA NTRS1978

Voyager radio occultation investigations at Saturn

Voyager will use dual-frequency 3.5 and 13 cm wavelength radio occultation techniques to study the atmospheres and ionospheres of Saturn and Titan, and the rings of Saturn. At Titan radio occultation is predicted to probe the atmosphere to the surface. The existence of a surface could be confirmed by detection of an obliquely scattered echo. At Saturn the two Voyager encounters will provide occultation measurements of temperate and equatorial regions of the atmosphere and ionosphere, and of the rings. The atmosphere will also be probed in polar regions during the deepest portions of the occultation. Both frequency and intensity data will be collected and jointly analyzed to study temperature-pressure profiles, and to derive information on atmospheric shape, turbulence, and weather. For the rings, Voyager will provide measurements of the complex (amplitude and phase) radio extinction and angular scattering functions of the ring particles as a function of wavelength, polarization, and radial distance from Saturn.

Tyler, G. L.↗
NASA NTRSDate not supplied

Nephele: An Entry Probe & Sonde Concept for a Venus Ride-Along or Small Spacecraft Mission

Nephele is a Venus atmospheric descent probe concept designed to analyze cloud, haze, and dust particles. It combines a unique set of technologies (Figure 1): recently developed thermal protection materials (3D-CC and HEEET), aerosol sampling technologies with heritage in both planetary and airborne science (high-speed inlets and particle separation), and rapid, robust optical analysis instruments (such as the VOLTR dual spectrometer). Nephele is designed to be complentary to other efforts such as DAVINCI and Venera-D, which target Venus atmospheric gas analysis, by specifically targeting cloud and haze particles.

Nephele↗
NASA NTRS2018

Aerothermal Design of a Common Probe for Multiple Planetary Destinations

Estimate the mass of the Thermal Protection System (TPS) for a single design construct of an atmospheric entry probe with a rigid aeroshell, which could be used at five destinations, i.e. Venus, Saturn, Uranus, Neptune, and perhaps, Jupiter. The entry mass of the probe is 400 kg with a ballistic coefficient of 216 kg/m2. Process: The 3DoF trajectory simulation program Traj, coupled with the TPS response program FIAT was used for simulation and design. The assumed atmospheric models were VIRA (Venus-GRAM) for Venus, the Julianne Moses' model for Saturn, a NASA Ames engineering model for Uranus, Neptune-GRAM for Neptune, and Galileo Probe (Al Seiff's) result for Jupiter.

Allen, Gary A., Jr.↗
NASA NTRS1983

Return to Jupiter - Project Galileo

The mission profile, instrumentation, and mission objectives of the Galileo probe are described. Scheduled for Shuttle launch in 1986, with a boost from the Centaur upper stage, the probe will require over 2 yr to reach the Jovian system. An atmospheric entry probe will be released during Jupiter approach, and the orbiting module will relay the temperature, pressure, radio signals, spectroscopy, magnetometry, and particle counts, originating from the parachuting probe. The orbiting module will then continue on to a series of flybys and orbits around the Jovian moons by using a gravity assist from Jupiter after each pass of a moon. The orbiter will record spectrometric, radiometric, dust, visual, magnetic, and radio propagation data. The television camera is a CCD device with 640,000 diodes forming an 800 x 800 array in one square centimeter.

Johnson, T. V.↗
NASA NTRS1986

Galileo probe battery systems design

NASA's Galileo mission to Jupiter will consist of a Jovian orbiter and an atmospheric entry probe. The power for the probe will be derived from two primary power sources. The main source is composed of three Li-SO2 battery modules containing 13 D-size cell strings per module. These are required to retain capacity for 7.5 years, support a 150 day clock, and a 7 hour mission sequence of increasing loads from 0.15 to 9.5 amperes for the last 30 minutes. This main power source is supplemented by two thermal batteries (CaCrO4-Ca) for use in firing the pyrotechnic initiators during the atmospheric staging events. This paper describes design development and testing of these batteries at the system level.

Dagarin, B. P.↗
NASA NTRS1974

Impact of science objectives and requirements on probe mission and system design

Problem areas in probe science technology are discussed that require a solution before probe systems can actually be designed. Considered are the effects of the model atmospheres on probe design; secondly, the effects of implementing the requirements to locate and measure the clouds and, trade-offs between descent sampling and measurement criteria as they affect probe system design.

Ledbetter, K. W.↗
NASA NTRS1974

Science payload

The representative science payload of an outer planet atmospheric entry probe is described. The instrumental details are based on experiments that have been successfully flown in the atmospheres of Earth and Venus. The incorporation of these instruments into an outer planet probe requires a strong interaction between instrument designer and probe designer. The installation of the instruments into a 250 lb entry probe is illustrated.

Myers, H.↗
NASA NTRS1985

Temperature structure in the lower atmosphere of Venus - New results derived from Pioneer Venus entry probe measurements

The Pioneer Venus Small-Probe Net Flux Radiometer temperature sensor and its calibration, the thermal model of the sensor head, the procedure for deriving atmospheric temperature from the sensor temperatures, and the new temperature results for each entry probe are reported. The new results are compared with those of the Small-Probe Atmospheric Structure experiment and with simple models of diurnal and latitudinal temperature contrasts. A dynamical inconsistency between these results and low-latitude measurements by the Sounder probe is described, and possible ways to resolve it are considered.

Sromovsky, L. A.↗
NASA NTRS1972

Spectral observations of Venus in the frequency interval 18.5-24.0 GHz - 1964 and 1967-68.

During July 1964, Venus was observed with a tunable radiometer at eight frequencies in the interval 20.6-24.0 GHz and again at six frequencies in the interval 18.5-24.0 GHz during an eight-month period beginning approximately one month after the inferior conjunction of 1967. Microwave spectra for these frequency intervals were computed using the results from Mariner 5 and Veneras 4-7 and compared to these data. One block of data suggests a lower percentage of H2O than that reported by the Venera probes, while other blocks may be consistent with the probe data. These data therefore suggest that the distribution of water vapor down to atmospheric levels probed at these frequencies may vary with time or else the Venera probes may have detected localized enhancements in water vapor.

Jones, D. E.↗
NASA NTRS1977

Outer planet probe engineering model thermal vacuum test

A thermal vacuum test was performed on the engineering model of the outer planets atmospheric entry probe. Steady state runs at three simulated radioisotope heating unit loads and one transient run simulating the pre-entry power profile were made to determine the thermal characteristics of the engineering model. An analytic simulation of the model was correlated to the test data. Several steady state and one transient run were made with the model attached to the spacecraft adapter to determine the thermal interface between the model and the adapter.

Grote, M. G.↗
NASA NTRS1991

Waves in Venus's middle and upper atmosphere - Implications of Pioneer Venus probe data above the clouds

This paper reevaluates Pioneer Venus probe data which show the presence of waves in Venus's middle and upper atmosphere. The data are extended to 138 km. Uncertainties in the temperature are typically about 0.1 times amplitude, supporting the reliability of large-amplitude oscillations approaching 40 K at 120 km. Growth rates above 100 km follow approximately the inverse square root of density and 'saturation' occurs. The waves then break at the 120 km level, providing a source for the 'friction' required in models to match the observed day-night temperature contrast in the lower thermosphere. The data correlated to an unexpected degree with temperatures from the Pioneer Venus orbiter atmospheric drag experiment. The observations lead to the suggestion that the thermospheric waves are solar-fixed, induced either by the major subsidence across the termination or as continuation upward of waves in the middle atmosphere.

Seiff, Alvin↗
NASA NTRS1991

Galileo

The purpose of the Galileo missions is to make observations of Jupiter and its satellites using an orbiting spacecraft and an atmospheric entry probe. The mission will determine the chemical composition and physical state of the Jovian atmosphere and its satellites, and the topology and behavior of the magnetic field and energetic particle flux of Jupiter. The mission plan calls for a Venus Earth Earth Gravity Assist (VEEGA) trajectory having a launch to end of mission duration of approximately 8 years. The Galileo spacecraft was placed in Earth orbit by the Space Transportation System (STS) on October 18, 1989. The Inertial Upper Stage (IUS) placed the spacecraft on a trajectory to encounter Venus on February 10, 1990. Information is given in tabular form for coverage goals, Deep Space Network (DSN) support, frequency assignments, telemetry, command, and tracking support responsibility.

Ausman, N. E.↗