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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
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NASA NTRS2018

NASA Low-Power Stirling Convertor for Small Landers, Probes, and Rovers Operating in Darkness

A variety of mission concepts have been studied by NASA and the U. S. Department of Energy that would utilize low power Radioisotope Power Systems (RPS) for landers, probes, and rovers. These missions would contain science measuring instruments distributed across planetary surfaces or near objects of interest where solar flux is insufficient for using solar cells. Landers could be used to provide data like wind, temperature, pressure, seismic activity, and other planetary measurements to mission planners or future explorers. The studies proposed using fractional versions of the General Purpose Heat Source (GPHS) or multiple Light Weight Radioisotope Heater Units (LWRHU) to heat power conversion technologies for science instruments and communication. Dynamic power systems are capable of higher conversion efficiencies, which could enable equal power using less fuel or more power using equal fuel, when compared to less efficient static power conversion technologies. Providing spacecraft with more power would decrease duty cycling of basic functions and, therefore, increase the quality and abundance of science data. Low power Stirling convertors are being developed at NASA Glenn Research Center (GRC) to provide future micro spacecraft with electrical power by converting heat from one or more LWRHUs. An initial design converts multiple Watts of heat to one Watt of electrical power output using a Stirling convertor. Development of the concept includes maturation of convertor and controller designs, performance evaluation of an evacuated metal foil insulation, and development of system interfaces.

Wilson, Scott D.↗
NASA NTRS2018

NASA Low Power Stirling Convertor for Small Landers, Probes, and Rovers Operating in Darkness

A variety of mission concepts have been studied by NASA and the U. S. Department of Energy that would utilize low power Radioisotope Power Systems (RPS) for landers, probes, and rovers. These missions would contain science measuring instruments distributed across planetary surfaces or near objects of interest where solar flux is insufficient for using solar cells. Landers could be used to provide data like wind, temperature, pressure, seismic activity, and other planetary measurements to mission planners or future explorers. The studies proposed using fractional versions of the General Purpose Heat Source (GPHS) or multiple Light Weight Radioisotope Heater Units (LWRHU) to heat power conversion technologies for science instruments and communication. Dynamic power systems are capable of higher conversion efficiencies, which could enable equal power using less fuel or more power using equal fuel, when compared to less efficient static power conversion technologies. Providing spacecraft with more power would decrease duty cycling of basic functions and, therefore, increase the quality and abundance of science data. Low power Stirling convertors are being developed at NASA Glenn Research Center (GRC) to provide future micro spacecraft with electrical power by converting heat from one or more LWRHUs. An initial design converts multiple Watts of heat to one Watt of electrical power output using a Stirling convertor. Development of the concept includes maturation of convertor and controller designs, performance evaluation of an evacuated metal foil insulation, and development of system interfaces.

Wilson, Scott↗
NASA NTRS2019

The 2008 Mars Phoenix Lander Thermal and Evolved Gas Analyzer (TEGA) Dataset: Placing Easily Interpretable Evolved Gas Data on the Planetary Data System (PDS)

The Phoenix Scout Lander mission investigated the north polar region of Mars in 2008 with the goal to study the history of water, assess the past/present Martian climate, search for organics, and evaluate the potential for past/present microbial habit-ability on Mars. To accomplish this goal, the Phoenix Lander’s Thermal and Evolved-Gas Analyzer (TEGA) instrument assessed the gas composition of the Martian atmosphere and evaluated the mineralogy of the Martian regolith. The TEGA instrument consisted of eight small ovens connected to a 4 channel magnetic sector mass spectrometer. The ovens heated soil samples from ambient to 1000°C where the gases (e.g., H2O, CO2, etc.) evolved from thermal decomposition of mineral phases were analyzed by the mass spectrometer. Minerals thermally decomposed at characteristic temperatures and the evolving gases indicated the presence of perchlorate, carbonate, and hydrated phases in the Phoenix landing site soils.

Garcia, A. H.↗
NASA NTRS2019

Analysis of Base Heating Environment During Ground Testing of a Lunar Lander Demonstrator

Introduction: This lunar lander demonstrator, known as XL-1T (terrestrial), is a collaborative effort between Masten Space Systems and NASA, under NASA’s Lunar CATALYST (also known as Lunar Cargo Transportation and Landing by Soft Touchdown) initiative; The lunar lander is a reusable terrestrial test bed for Masten’s powered decent landing system, and will be controlled by four throttleable main engines utilizing green hypergolic propellants; One of the concerns for a four-engine vehicle like this demonstrator, is the potential for a severe base-heating environment, caused by the formation of a “fountain jet” during testing. Fountain jet is an unique base flow physics which was discovered during the development of the DC-X vehicle.

Wang, Ten-See↗
NASA NTRS2019

Numerical Study of Lander Engine Plume Impingement on the Surface of Europa

Plume exhaust from lander engines would be of concern when landing on the surface of Europa since it could have detrimental effects on both the landing surface and powered descent vehicle. The plume could also entrain particles and redirect them up toward the landing vehicle, as well as erode and contaminate the surface where science would be conducted. In this work, a numerical methodology is developed and validated to conduct a first-order assessment of individual engine plumes of a potential Europa Lander vehicle. Computational Fluid Dynamics (CFD) is used to solve the flow field inside and immediately downstream of the nozzle, while the Direct Simulation Monte Carlo (DSMC) method is applied further downstream where the flow becomes rarefied. An interface between the two domains is defined where macroscopic flow data is passed from the CFD domain to the DSMC domain, establishing a one-way coupling. Plume pressure and velocity fields, as well as ground heating, pressure and density flux profiles, are obtained at altitudes from 25 m down to 10 m, spanning the final stages of landing. The codes and methodologies used in this study are successfully validated with simulations conducted by Morris et al. of the Apollo Lunar Module Descent Engine (LMDE) exhaust plume impinging onto the lunar surface.

Lam, Rebekah↗
NASA NTRS2019

Small and Lightweight Laser Retro-Reflector Arrays for Lunar Landers

A set of small and lightweight laser retro-reflector arrays (LRAs) was fabricated and tested for use on lunar landersunder NASA's Commercial Lunar Payload Service program. Each array contains eight 1.27-cm-diameter cornercube retro-reflectors mounted on a dome-shaped aluminum structure. The arrays are 5.0cmin diameter at the base,1.6 cm in height, and 20 g in mass. They can be tracked by an orbiting laser altimeter, such as the Lunar OrbiterLaser Altimeter, froma distance of a few hundred kilometers or by a landing lidar on future lunar landers. TheLRAsdemonstrated a diffraction-limited optical performance. They were designed and tested to survive and function ontheMoon for decades,well after the lander missions are completed.

Sun, Xiaoli↗
NASA NTRS2019

A Permanent Human Lunar Surface Presence Enabled by a CLV Class JUMP Lander

There are compelling advantages of a human presence on the surface of the Moon, as evidenced partly by the preponderance of lunar surface architectures that have existed throughout NASA, industry, and academia since the Apollo program. This paper specifically advocates and illustrates an example of a permanent human lunar surface presence enabled by a commercial launch vehicle (CLV) class Joinable Undercarriage to Maximize Payload (JUMP) lunar lander. The paper will discuss purposes for such a surface presence, including SPD-1 fulfillment, global collaboration, US industry advancement, US government leadership in spaceflight, a Mars dress rehearsal, Mars collaborative exploration, and lunar village development. An architectural description will be presented, including site selection, primary elements, and surface configuration. Element and lander allocation to CLV and Space Launch System (SLS) rockets will be discussed in terms of launch vehicle selection philosophy and allocation to specific launch manifests. This will enable a presentation of a lunar campaign spanning the period from 2026 to 2056. In conclusion, various aspects of the architecture will be suggested for further study.

Howard, Robert L., Jr.↗
NASA NTRS2020

Optical Characterization of Laser Retroreflector Arrays for Lunar Landers

Laser Retroreflector Array for Lunar Landers (LRALL) is a small optical instrument designed to provide a target for precision laser ranging from a spacecraft in lunar orbit, enabling geolocation of the lander and its instrument suite and establishing a fiducial maker on the lunar surface. Here we describe the optical performance of LRALL at visible and near-infrared wavelengths. Individual corner cube reflectors (CCRs) within LRALL were tested for surface flatness and dihedral angle values. We also imaged the far-field diffraction patterns of individual CCRs as well as the entire retroreflector array over the range of possible incident angles to extract the optical cross section as a function of viewing angle. We also measured the optical properties of one of the CCRs over the lunar temperature range (100 K to 380 K) and found no significant temperature-dependent variance. The test results show LRALL meets the design criteria and can be ranged to from elevation angles above 30° with respect to the instrument base from an orbital laser altimeter such as the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO). This work summarizes the test data and serves as a guide for future laser ranging to these retroreflector arrays.

Daniel R Cremons↗
NASA NTRSDate not supplied

The Behavior of High-Velocity Dust Generated by Lander Plumes in the Lunar Environment

Lunar lander plumes are known to accelerate fine dust to speeds exceeding 2 km/s, and the resultant ejecta may remain in lunar orbit for extended periods of time. Such ejecta could become hazardous to objects in lunar orbit as well as systems on the surface. In order to understand the impact on orbiting lunar infrastructure such as Gateway, as well as assets on the lunar surface, here we consider the dynamics of the resultant high-velocity plume ejecta. Initial conditions were set by the expected near-term lunar activity and the known cone of accelerated dust generated by previous lunar landings. The effects of regular 3-body gravitation, solar radiation pressure, and electric field are included in the model. It is found that although the majority of sub-μm dust is carried away by solar wind and electric fields, about ~10% of the dust between 1.7 km/s and 2.3 km/s reimpacts the surface, much of it near the landing site. The hazard posed by that debris is a function of lander mass and distance from the landing site. The Gateway, when orbiting in the nominal NRHO at the time of a landing, is not expected to be significantly affected by the dust. However, other spacecraft in less elliptic orbits may be at greater risk.

Ejecta↗
NASA NTRSDate not supplied

Mars Sample Return, Sample Retrieval Lander, Reaction Control System Jet Interaction Supersonic Wind Tunnel Test Overview with CFD Predictions

NASA's Mars Sample Return campaign will be launching several missions over the next decade that will work together to return rock samples from Mars back to Earth. The Sample Retrieval Lander (SRL) will deliver the Mars Ascent Vehicle and fetch rover to the surface of Mars in 2006. Rock samples collected by the Mars 2020 Perseverance rover, landing in early 2021, will be loaded on the the ascent vehicle to be launched into Mars orbit for retrieval by yet another spacecraft. The Sample Retrieval Lander will be a blunt entry capsule similar to past Mars entry vehicles like Mars Science Laboratory and Viking. The vehicle will fly a guided entry, using a small lift vector produced by a non-zero trim angle of attack to eliminate downrange and crossrange position errors at the point of parachute deploy. This energy and heading management is achieved with a reaction control system (RCS) that directs the bank angle of the vehicle and also minimizes unwanted capsule dynamics. The reaction control system and control design is based on the Mars Science Laboratory and Mars 2020 RCS systems. However, due to packaging constraints, the backshell of this new entry vehicle has a different geometry than those earlier designs. To certify the RCS system for flight the project must characterize the jet plume interactions with the capsule backshell that could impair or significantly augment the RCS control authority. This characterization will be done through a combination of computational fluid dynamics (CFD) analysis and wind tunnel test. Two candidate arrangements of the RCS jets have been identified for the SRL vehicle and are currently under evaluation before final selection. The aero/RCS plume interactions of these candidate configurations have been measured in a supersonic wind tunnel test in NASA Langley's Unitary Plan Wind Tunnel. The test was conducted in the fall of 2020 and data is currently being reduced. An overview of the candidate RCS configurations are presented here with an overview of the wind tunnel model design, jet scaling and scaled nozzle design, and the test matrix. Preliminary CFD runs are presented with an assessment of the predicted plumes and their interaction with the wake flow of the vehicle. The predicted effects of the model sting is provided as well. This high fidelity wind tunnel test is being conducted much earlier in the SRL project than would normally be done. The test was funded as part of a CFD evaluation task funded by NASA's Aerosciences Evaluation and Test Capabilities Project. The objective of the evaluation task was to compare the ability of CFD to predict complex flows with data that can be measured in the Langley Unitary Plan Wind Tunnel. RCS Jet interactions were selected as a type of complex flow that is important to NASA missions. In addition to providing useful data to the SRL project, there was added emphasis on quantifying the accuracy of the CFD predictions and wind tunnel test data. An overview of the uncertainty quantification methodologies for computational and experimental portions of this test is presented.

blunt body↗
NASA NTRSDate not supplied

The Generation and Application of Paylaod Thermal Environments for a Lunar Lander Mission

In today’s space industry many organizations develop payloads or other components that will fly on a vehicle or lander developed by a different organization. This creates a challenge for the payload developers of knowing the thermal environment, including effects from the spacecraft, of their instrument because the payload engineers will not have continuous access to an up-to-date thermal model of the spacecraft. To circumvent the vehicle developer having to provide a thermal model of the spacecraft to payload developers for detailed thermal analysis, the vehicle developer can provide environmental data to the payload engineers to apply to their payload model, instead. This data must include the boundary temperatures where the payload is mounted, sink temperatures, and both incident solar and infrared thermal flux. This paper will describe the method used to generate thermal environments for payloads on the Astrobotic Lunar Lander and how those environments were applied to an example payload, the Neutron Measurement at the Lunar Surface (NMLS) instrument. This work is unique because a standard method for generating and delivering payload environments does not exist. Benefits and drawbacks of using this method will also be discussed.

Thermal Environments↗
NASA NTRS1996

Mars Dynamics from Earth-Based Tracking of the Mars Pathfinder Lander

Measurements of Mars' rotational variations can be conducted via Earth-based radio tracking observations of the Mars Pathfinder lander during an extended mission. Two-way range measurements between an Earth antenna and the lander will enable precise monitoring of the planet's orientation and length-of-day variation, allowing details of Mars' internal structure and global surface/atmosphere interactions to be determined with precision for the first time.

two-way↗
NASA NTRS1995

Mars Lander Robotics and Machine Vision Capabilities for in situ Planetary Science

We overview our recent progress in lander-based robotics for Mars planetary science. Utilizing a 1:1 scale laboratory replica of the NASA Mars Surveyor '98 mission, JPL engineers and Mars sciencce colleagues have demonstrated approaches to lander science functions such as robotic sample acquisiiton and deposition, end-effector based microscopic viewing, hand-carried science instrument data collection, and science instrument emplacement by a robot.

robotics↗
NASA NTRS2018

Cobalt: Terrestrial Flight Test of Landing Navigation Using Lander Vision System with Navigation Doppler Lidar

COBALT (CoOperative Blending of Autonomous Landing Technologies) is a NASA technology development and test program to advance precision landing capabilities for future soft landers. The COBALT payload demonstrated terrain relative navigation utilizing the Lander Vision System and Navigation Doppler Lidar sensors on the Masten Space Systems Xodiac rocket. In spring 2017, the program culminated in two open-loop free flights to 500 m altitude with downrange diverts of 300 m. The COBALT system performed well, navigating within meters of the Xodiac vehicle’s GPS-based solution. This paper outlines details of the navigation filter and its performance during the test campaign.

Carson, John M. III↗
NASA NTRS2018

All-Metal Dual Frequency RHCP High Gain Antenna for the Extreme Environments of a Potential Europa Lander

A new all-metal dual-frequency RHCP high gain antenna is under development at NASA’s Jet Propulsion Laboratory for a potential Europa Lander. The antenna is mainly made of metal so it could survive the harsh environment conditions (i.e. very low temperature and high radiation and ESD levels). The antenna is also flat to meet drastic volume constraints and has efficiencies higher than 80% at both the uplink and downlink X-band Deep Space frequency bands. This antenna is a key component for the potential mission enabling Direct Link to Earth (DTE) from and Direct-from-Earth (DFE) to the lander without any relay.

Estabrook, Polly↗
NASA NTRS2018

Compact Low Power Avionics for the Europa Lander Concept and Other Missions to Ocean Worlds

This paper presents the results of NASA’s Game Changing Technology development entitled “Ultra Low Temperature Electronics” and ColdTech technology effort entitled “Cold Survivable Distributed Motor Controller”. The purpose of these back-to-back projects is to address the Command & Data Handling (CDH), Power and Motor Control needs for missions to ocean worlds such as the potential Europa Lander project. We addressed the mass reduction challenge by developing the key technologies necessary to design a next generation compact motor control avionics. The project’s goal is to allow a Europa Lander to last longer on the surface and provide more room for additional science by reducing the volume, mass and power of its avionics and the amount of energy required to keep the avionics warm.

Suh, Jong-ook↗
NASA NTRS2019

Sampling tool concepts for Enceladus Lander in-situ analysis

A potential future in-situ lander mission to the surface of Enceladus could be the lowest cost mission to determine if life exists beyond Earth since material from the subsurface ocean, where the presence of hydrothermal activity has been strongly suggested by the Cassini mission, is available on its surface after being ejected by plumes and then settling on the surface. In addition, the low radiation environment of Enceladus would not significantly alter the chemical makeup of samples recently deposited on the surface. A study was conducted to explore various sampling devices that could be used by an in-situ lander mission to provide 1cc to 5cc volume samples to instruments. In addition to temperature and vacuum environmental conditions, the low surface gravity of Enceladus (1% of Earth gravity) represents a new challenge for surface sampling that is not met by sampling systems developed for microgravity (e.g., comets and asteroids) or higher gravity (e.g., Europa 13%g, Moon 16%g, or Mars 38%g) environments. It is desired to acquire surface plume material that has accumulated in the top 1cm to ensure acquisition of the least processed material. Several sampling devices were developed or adapted and then tested in simulated conditions that resemble the Enceladus surface properties. These devices and test results are presented in this paper.

Genta, Giancarlo↗
NASA NTRS2019

Large all-Metal Dual-Frequency Circularly Polarized High Gain Antenna for potential Europa Lander

A new all-metal dual-frequency RHCP high gain antenna is under development at NASA’s Jet Propulsion Laboratory for a potential Europa Lander. The antenna is mainly made of metal so it could survive the harsh environment conditions (i.e. very low temperature and high radiation and ESD levels). The antenna is also flat to meet drastic volume constraints and has efficiencies higher than 80% at both the uplink and downlink X-band Deep Space frequency bands. This antenna is a key component for the potential mission enabling Direct Link to Earth (DTE) from and Direct-from-Earth (DFE) to the lander without any relay.

Estabrook, Polly↗