Radiating flows during entry into planetary atmospheres.
Radiation properties of shock layer and nonequilibrium flows around probes entering earth, Mars, Venus and Jupiter atmosphere
Boughner, R. E.↗
SEARCH · Search NASA
Results for “Entry Probe”
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Aerosciences Implications for Uranus Aerocapture
Exploration of Uranus has been indicated as the highest priority new flagship planetary science missions for NASA in the 2022 Decadal Survey. Due to Uranus’ location as the second furthest planet from the Sun, interplanetary flight times of a traditional propulsive-capture orbiter can expect to take 13-15 years to reach Uranus while requiring up to two-thirds of the launch mass budget to be allocated to propellant alone. Aerocapture presents an alternative means to capture orbit around Uranus by using aerodynamic forces generated from flight through the planetary atmosphere to decelerate to orbital insertion while reducing time in interplanetary transit time and increasing on-orbit payload mass. To date, only one spacecraft (Voyager 2) has visited Uranus, and there have been no missions which have entered its atmosphere. While knowledge of planetary entry at rocky terrestrial planets with Air (N2/O2) and CO2 dominated atmospheres has greatly advanced over the past decades with a variety of missions to learn from, the H2/He composition and much larger atmosphere of ice giants such as Uranus poses new aerosciences implications which are not fully understood. These implications must be better understood not only for aerocapture, but for planetary entry at Uranus as a whole (such as a Uranus probe, as proposed by the 2022 Decadal Survey), as well as other ice giants like Neptune. To conduct a proper analysis of aerocapture methods, aerodynamic and aerothermal analysis of flight trajectories in Uranus atmosphere are required. Previous work has investigated aerocapture at Neptune (with similar atmosphere to Uranus) using a Mid-L/D configuration. Additional previous work considers the convective heating experienced in H2/He atmospheres. The current work looks to use heritage Low-L/D configurations, adding technical depth and maturation to analysis previously performed by Girija. Atmospheric flight at ice giants presents unique challenges, including but not limited to: fidelity of atmospheric models, large entry velocities due to location in the solar system, extended flight in rarefied flow conditions due to atmospheric scale, and unusual aerodynamic flow properties specific to Uranus and Ice Giant atmospheres.
Eli Shellabarger↗
Venus Multiprobe Mission
A summary of the proposal for the Discovery Program Venus Multiprobe Mission (VMPM) which was submitted in 1994 will be presented. The major goal of the mission was to provide sufficient observations of winds and thermal structure in the Venus atmosphere that the mechanism producing the atmospheric superrotation could be identified. The superrotation has been a major unsolved problem of planetary science for over 30 years. In spite of many theoretical efforts and many spacecraft missions to Venus, the principal driving mechanism(s) remain undetermined. Sixteen small probes, modeled after the Pioneer Venus small probes, would enter the Venus atmosphere, and measure winds, temperatures, and pressures from 60 km to the surface. Towards the bottom of the atmosphere, measurements would be made at 10 meter intervals. Temperature and pressure measurements are similar to those used on Pioneer Venus, but are four times more sensitive. Winds would be obtained by dual-frequency, differential. long-baseline interferometry, using S- and X-band transmitters on the probes, and four receiving telescopes round the Pacific rim. The precision of wind measurements is 0.05 ms- 1 or better, at least twenty times more precise than for Pioneer Venus. Ground based observations occurring in conjunction with the multiprobe entries would provide a temporal context for the upper boundary to the probe observations. UV and near IR features would be tracked for periods of hours to weeks to obtain cloud level zonal mean and transient eddy circulations with accuracies of 10 /ms or better. The data would be processed into wind and opacity maps. A hierarchy of atmospheric numerical models would be used to distinguish different dynamical elements existing in the data. Primary among the models was the development of a Venus general circulation model containing all known physical processes.
Young, Richard E.↗
Overview of the Galileo Probe Mission to Jupiter
The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995, for the first time directly sampling the atmosphere of one of the outer planets. The entry was the most difficult ever attempted in terms of heat and deceleration loads. The probe and all scientific instruments functioned successfully, and returned data on composition, clouds, thermal structure, winds, energy balance, lightning, and inner radiation belts. A summary of major science objectives and results is presented.
Young, R. E.↗
Overview of the Galileo Probe Mission to Jupiter
The Galileo Probe entered the atmosphere of Jupiter on December 7, 1995, for the first time directly sampling the atmosphere of one of the outer planets. The entry was the most difficult ever attempted in terms of heat and deceleration loads. The probe and all scientific instruments functioned successfully, and returned data on composition, clouds, thermal structure, winds, energy balance, lightning, and inner radiation belts. A probe mission overview is presented, highlighting the key mission events and major science objectives. The purpose of the overview is to set the stage for the following papers which describe findings from the probe scientific investigations and discuss implications of the probe results.
Young, Richard E.↗
Work on Planetary Atmospheres and Planetary Atmosphere Probes
A summary final report of work accomplished is presented. Work was performed in the following areas: (1) Galileo Probe science analysis, (2) Galileo probe Atmosphere Structure Instrument, (3) Mars Pathfinder Atmosphere Structure/Meteorology instrument, (4) Mars Pathfinder data analysis, (5) Science Definition for future Mars missions, (6) Viking Lander data analysis, (7) winds in Mars atmosphere Venus atmospheric dynamics, (8) Pioneer Venus Probe data analysis, (9) Pioneer Venus anomaly analysis, (10) Discovery Venus Probe Titan probe instrument design, and (11) laboratory studies of Titan probe impact phenomena. The work has resulted in more than 10 articles published in archive journals, 2 encyclopedia articles, and many working papers. This final report is organized around the four planets on which there was activity, Jupiter, Mars, Venus, and Titan, with a closing section on Miscellaneous Activities. A major objective was to complete the fabrication, test, and evaluation of the atmosphere structure experiment on the Galileo probe, and to receive, analyze and interpret data received from the spacecraft. The instrument was launched on April 14, 1989. Calibration data were taken for all experiment sensors. The data were analyzed, fitted with algorithms, and summarized in a calibration report for use in analyzing and interpreting data returned from Jupiter's atmosphere. The sensors included were the primary science pressure, temperature and acceleration sensors, and the supporting engineering temperature sensors. Computer programs were written to decode the Experiment Data Record and convert the digital numbers to physical quantities, i.e., temperatures, pressures, and accelerations. The project office agreed to obtain telemetry of checkout data from the probe. Work to extend programs written for use on the Pioneer Venus project included: (1) massive heat shield ablation leading to important mass loss during entry; and (2) rapid planet rotation, which introduced terms of motion not needed on Venus. When the Galileo Probe encountered Jupiter, analysis and interpretation of data commenced. The early contributions of the experiment were to define (1) the basic structure of the deep atmosphere, (2) the stability of the atmosphere, (3) the upper atmospheric profiles of density, pressure, and temperature. The next major task in the Galileo Probe project was to refine, verify and extend the analysis of the data. It was the verified, and corrected data, which indicated a dry abiabatic atmosphere within measurement accuracy. Temperature in the thermosphere was measured at 900 K. Participation in the Mars atmospheric research included: (1) work as a team member of the Mars Atmosphere Working Group, (2) contribution to the Mars Exobiology Instrument workshop, (3) asssistance in planning the Mars global network and (4) assitance in planning the Soviet-French Mars mission in 1994. This included a return to the Viking Lander parachute data to refine and improve the definition of winds between 1.5 and 4 kilometer altitude at the two entry sites. The variability of the structure of Mars atmosphere was addressed, which is known to vary with season, latitude, hemisphere and dust loading of the atmosphere. This led to work on the Pathfinder project. The probe had a deployable meteorology mast that had three temperature sensors, and a wind sensor at the tip of the mast. Work on the Titan atmospheric probe was also accomplished. This included developing an experiment proposal to the European Space Agency (ESA), which was not selected. However, as an advisor in the design and preparation of the selected experiment the researcher interacted with scientist on the Huygens Probe Atmosphere Structure Experiment. The researcher also participated in the planning for the Venus Chemical Probe. The science objectives of the probe were to resolve unanswered questions concerning the minor species chemistry of Venus' atmosphere that control cloud formation, greenhouse effectiveness, and the thermal structure. The researcher also reviewed problems with the Pioneer Venus Probe, that caused anomalies which occurred on the Probes at and below 12.5 km level of the Venus' atmosphere. He convened and participated in a workshop that concluded the most likely hardware cause was insulation failure in the electrical harness outside the Probes' pressure vessels. It was discovered that the shrink tubing material failed at 600K. This failure could explain the anomalies experienced by the probes. The descent data of the Pioneer probes, and the Soviet Vega Lander was analyzed to evaluate the presence of small scale gravity waves in and below the Venus cloud layer.
Lester, Peter↗
Aeroheating Environments of Aerocapture Systems for Uranus Orbiters
Aeroheating environments for an aerocapture system enabling flagship-class science at Uranus are presented. Applicability of a low lift-to-drag entry vehicle aeroshell with flight heritage for Martian entries is considered in the context of an end-to-end Uranus orbiter and probe mission design using aerocapture for orbit insertion. A feasible trajectory space for aerocapture orbit insertion based on various launch opportunities and interplanetary trajectories yield atmosphere-relative entry velocities between 22 km/s and 31 km/s with maximum freestream densities on the order of 10−5 kg/m3. A preliminary study of the aerothermal environments for the entire trajectory space is discussed followed by a more detailed study of the nominal design trajectories. Design conditions are based on laminar, thermochemical nonequilibrium Navier-Stokes flowfield simulations with coupled radiation transport for full lift-up (deep) and lift-down (shallow) design trajectories. Convective heating is found to be the dominant heating mode, with radiation accounting for only 1 % to 5 % of the total heat flux for the design trajectories. The peak design conditions are found to be 422 W/cm2 for heat flux, 10.5 kPa for pressure, 149 Pa for shear stress, and 88.1 kJ/cm2 for the total heat load.
Uranus↗
Aeroheating Environments of Aerocapture Systems for Uranus Orbiters
Aeroheating environments for an aerocapture system enabling flagship-class science at Uranus are presented. Applicability of a low lift-to-drag entry vehicle aeroshell with flight heritage for Martian entries is considered in the context of an end-to-end Uranus orbiter and probe mission design using aerocapture for orbit insertion. A feasible trajectory space for aerocapture orbit insertion based on various launch opportunities and interplanetary trajectories yield atmosphere-relative entry velocities between 22 km/s and 31 km/s with maximum freestream densities on the order of 10 −5 kg/m 3 . A preliminary study of the aerothermal environments for the entire trajectory space is discussed followed by a more detailed study of the nominal design trajectories. Design conditions are based on laminar, thermochemical nonequilibrium Navier-Stokes flowfield simulations with coupled radiation transport for full lift-up (deep) and lift-down (shallow) design trajectories. Convective heating is found to be the dominant heating mode, with radiation accounting for only 1 % to 5 % of the total heat flux for the design trajectories. The peak design conditions are found to be 422 W/cm 2 for heat flux, 10.5 kPa for pressure, 149 Pa for shear stress, and 88.1 kJ/cm 2 for the total heat load.
Aerocapture↗
A study of the aerothermal entry environment
Turbulent flow-field solutions are presented for the forebody of a probe entering a nominal Jupiter atmosphere. A two-layer eddy viscosity model is used throughout the study. The solutions that include coupled ablation injection are significant in that they are the first flow-field solutions for a 45-deg spherically blunted cone, the forebody configuration for the Galileo probe. The sphere-cone solutions that include coupled ablation injection show that the radiative heating on much of the conical portion of the probe often exceeds the radiative heating predicted for the corresponding no-injection solution. Turbulence produces a marked decrease in the effectiveness of the ablation products to absorb radiation because of the way in which turbulence alters the structure and composition of the flow. Selected laminar and turbulent solutions are presented for a hyperboloid that demonstrate the effect of turbulence and probe configuration on surface heating and ablative mass loss. Furthermore, the sensitivity of the heating to variations in the turbulence model is presented for the sphere-cone configuration.
Moss, J. N.↗
Data link relay design
The data link for the Ames baseline probe as applied to the MJU spacecraft specifically with an entry at Uranus is analyzed. A frequency analysis, a trajectory analysis, and a discussion of the effects on the spacecraft design by the data link are presented. The possibilities of a two-way link are considered.
Parsons, P.↗
Parallelization of Lower-Upper Symmetric Gauss-Seidel Method for Chemically Reacting Flow
Development of technologies for exploration of the solar system has revived an interest in computational simulation of chemically reacting flows since planetary probe vehicles exhibit non-equilibrium phenomena during the atmospheric entry of a planet or a moon as well as the reentry to the Earth. Stability in combustion is essential for new propulsion systems. Numerical solution of real-gas flows often increases computational work by an order-of-magnitude compared to perfect gas flow partly because of the increased complexity of equations to solve. Recently, as part of Project Columbia, NASA has integrated a cluster of interconnected SGI Altix systems to provide a ten-fold increase in current supercomputing capacity that includes an SGI Origin system. Both the new and existing machines are based on cache coherent non-uniform memory access architecture. Lower-Upper Symmetric Gauss-Seidel (LU-SGS) relaxation method has been implemented into both perfect and real gas flow codes including Real-Gas Aerodynamic Simulator (RGAS). However, the vectorized RGAS code runs inefficiently on cache-based shared-memory machines such as SGI system. Parallelization of a Gauss-Seidel method is nontrivial due to its sequential nature. The LU-SGS method has been vectorized on an oblique plane in INS3D-LU code that has been one of the base codes for NAS Parallel benchmarks. The oblique plane has been called a hyperplane by computer scientists. It is straightforward to parallelize a Gauss-Seidel method by partitioning the hyperplanes once they are formed. Another way of parallelization is to schedule processors like a pipeline using software. Both hyperplane and pipeline methods have been implemented using openMP directives. The present paper reports the performance of the parallelized RGAS code on SGI Origin and Altix systems.
Yoon, Seokkwan↗
New Technologies Advancing Thermophysics
Researchers at NASA Ames in California have built a new facility that uses multiple 50-kW continuous wave lasers to add the capability for simulating radiative heating on thermal protection materials. The new facility, the Laser Enhanced Arc-jet Facility (LEAF-Lite), was added to NASA Ames’s Interaction Heating Facility arc-jet and now allows for test articles to be heated by both convective and radiative heat flux, making the facility more like flight. Using this new system, researchers can now simulate radiant heating with the laser and convective heating with the arc-jet simultaneously on a single test article. During its initial test in October 2017, the lasers radiatively heated a 6” x 6” Avcoat wedge sample to 405 W/sq.cm while the arc-jet simultaneously provided 160 W/sq.cm of convective heat, resulting in a total heat flux of 565 W/sq.cm. Radiative heating is more prevalent in missions with higher atmospheric entry speeds like the Orion space capsule or interplanetary scientific probes. Later this year, scientists will expand the spot size to cover 17” x 17” to test an Orion TPS panel.
Brandis, Aaron↗
Problems in Atmosphere Entry from Parabolic Orbits
Up to the present time we have been concerned with sending small instrumented probes into interplanetary space and larger bodies into near-earth satellite orbits. Only recently we have begun to recover intact some of these orbiting bodies and soon we will carry on this program to the recovery of manned satellites. In the not-too-distant future we will be concerned with transit to and from the moon and the planets. It is with the problems of entry into our atmosphere of these higher speed vehicles that this paper will be concerned.
Allen, H. Julian↗
Flow Redistribution Between Legs and Brain During STS 93 Re-Entry and Landing
The objective was to quantify bit by bit the arterial hemodynamic response to the successive acceleration induced fluid shifts during re-entry and landing. Method: The astronaut instrumented himself with a flat Doppler probe fixed on the skin, a blood pressure arm cuff, and 3 ECG electrodes. The ICMS (integrated cardiovascular monitoring system, 15x15x25 cu cm, battery powered) designed to monitor Blood pressure, ECG, cerebral and femoral flows was fixed below the astronaut sit in the middeck. Recordings started 5 minutes before de-orbiting (TIG) and stopped 5 min after wheels stop. Results. During re-entry blood pressure increased by 20% at TIG, and then by 25 to 30% during the highest Gz accelerations (approx 1 S g ) . The cerebral flow remained decreased by 10 to 15% below inflight value all during the Entry and landing phases. Conversely the femoral flow increased at TIG and entry ( + l0 to 20%), recovered at 0.lg, and then decreased in proportion with the Gz acceleration (-10% to -40% from 0.5g to 1.5g). The reduction in Femoral flow was associated with an opposite variation in lower limb vascular resistance. Consequently the cerebral flow/femoral flow ratio decreased at TIG and entry (-20%), and then increased according to the Gz acceleration level ( + l0 to +40% from 0.5 to 1.5g). Conclusion: During orthostatic tests (Stand LBNP tests) the cerebral to femoral flow ratio allowed to quantify the efficiency of the flow redistribution between these 2 areas and predicted orthostatic intolerance. In the present case the astronaut was found orthostatically tolerant at postflight tilt tests, but we suggest that during re-entry this parameter could predict the occurrence of syncope in severely disadapted astronauts.
Arbeille, P.↗
DAVINCI Venus Entry, Descent, and Landing Modeling and Simulation
The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission will launch in June 2029 and explore Venus via two flybys and a probe landing scheduled for June 2031. The goals of the mission are to study the origin, evolution, and current state of Venus and to understand if it was habitable at a point in the past. The entry, descent, and landing (EDL) concept of operations of the probe leverages on the successful Pioneer Venus large probe mission. The science objectives of the mission levy certain requirements on the EDL system, such as landing in the scientifically important Alpha Regio Tessera and telemetering several gigabytes of instrumentation data to the orbiting relay spacecraft before the probe impacts the surface. In order to optimize the EDL sequence of the lander and to verify key driving requirements, a six degree of freedom EDL flight mechanics simulation has been created based on the best available aerodynamic and atmospheric models valid for Venus. This paper describes the EDL modeling and simulation and summarizes the current flight mechanics results for the mission.
Soumyo Dutta↗
DAVINCI Venus Entry, Descent, and Landing Modeling and Simulation
The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission will launch in June 2029 and explore Venus via two flybys and a probe landing scheduled for June 2031. The goals of the mission are to study the origin, evolution, and current state of Venus and to understand if it was habitable at a point in the past. The entry, descent, and landing (EDL) concept of operations of the probe leverages on the successful Pioneer Venus large probe mission. The science objectives of the mission levy certain requirements on the EDL system, such as landing in the scientifically important Alpha Regio Tessera and telemetering several gigabytes of instrumentation data to the orbiting relay spacecraft before the probe impacts the surface. In order to optimize the EDL sequence of the lander and to verify key driving requirements, a six degree of freedom EDL flight mechanics simulation has been created based on the best available aerodynamic and atmospheric models valid for Venus. This paper describes the EDL modeling and simulation and summarizes the current flight mechanics results for the mission.
Soumyo Dutta↗
Atmospheric entry into Jupiter's atmosphere in view of recent flyby results
The paper examines the heating levels experienced by a probe entering Kliore's (1974) model of Jupiter's atmosphere and compares the results with those of the Jupiter model atmospheres given elsewhere (NASA SP-8069, 1971), with the heating levels of Tauber (1969) and Tauber and Wakefield (1971). The computations are made using a point-mass atmospheric entry trajectory program, i.e., the Allen-Eggers (1958) analysis and simple correlations of heating. Results of heating calculations are compared and discussed. It is found that the warm temperature bulge exists at a level too low in the atmosphere to affect any heating and that the nominal atmosphere fits Kliore's model atmosphere best insofar as heating is concerned. Previous estimates of the heating levels to be expected for a probe entering Jupiter's atmosphere are therefore unaffected by Kliore's postulated atmospheres.
Nachtsheim, P. R.↗
Jovian probe wake flowfield
The base heating problem in the Jovian probe was examined. The entire wake flowfield is defined to calculate the radiative heating to the base region of the Jovian probe. Engineering tools for calculating the probe's wake flowfield are developed. The near and far viscous and inviscid flowfields for three entry conditions are calculated. The flowfields include pressure, temperature, and species concentration for radiation analysis. A mathematical model used in the calculations is described. The results obtained indicate that temperatures in the Jovian probe range from 4,000 to 10,00 K and pressures range from 10 to 1,000 times the free stream value.
Engel, C. D.↗