a brief overview of high temperature technologies relevant

National Aeronautics and Space Administration

www.nasa.gov

A Brief Overview of High Temperature

Technologies Relevant for Venus Surface

Applications

G. W. Hunter and T. Kremic

NASA Glenn Research Center

Cleveland, OH


www.nasa.gov

• Introduction

• Electronics

• Packaging

• Communications

• Power

• Actuation

Outline


www.nasa.gov

• Venus has a very hostile environment with an average surface

temperature of 465C and surface atmospheric pressure of 90 atm.

in the presence of corrosive species

• Missions that have landed on the surface of Venus have typically

lasted at most ~2 hours due to the high temperatures and harsh

conditions

• Long term measurement of Venus planetary conditions has been

limited by the lack of electronics, communications, power, sensors,

instrument, and actuation systems operational in the harsh Venus

environment

• This presentation will provide a sampling of high temperature

technologies that may have an impact on future Venus exploration

• Concentrates on activities related to the Long-Lived In Situ Solar

System Explorer (LLISSE) project and the High Operating

Temperature Technologies (HOTTech) program

• Other examples may exist, but these activities are representative

of the State-of-the-Art as we understand it

Introduction


www.nasa.gov

• Technologies relevant for Venus surface applications may often have

their origin in other harsh environment applications e.g., aeronautics

or industrial processing

• Material systems and engineering approaches standardly used for

even harsh environment terrestrial applications may not be viable for

Venus missions

• A major challenge is operation in Venus surface conditions without

significant degradation and for extended periods of time

• Testing of proposed technologies in first at high temperature leading

up to Venus simulated conditions include relevant chemistry, is core

to technology advancement

Technology Development Overview

GEER: 92 atm, 465 °C + chemicalcomposition found at the surface ofVenus (CO2, N2, SO2, H20, CO, OCS, HCl, HF, and H2S)

• The status of Venus technology

development is in some cases at the

level of 1970’s to 1980’s technology; at

these levels significant science can be

accomplished.

• A mission needs a complete compliment

of relevant technologies for success

Before Packaging After 60-Day GEER Test

Material Choice (and GEER Testing) Matters

Wave Guide Before and After 60 Days of GEER Testing

(These materials react – grow crystals – will NOT work)

SiC Clock IC Chip Optical Microscope Photos

(These IC Materials Work - Chip operated for 60 days)

• LLISSE is a small and “independent” probes for Venus surface applications

• LLISSE acquires and transmits simple but important science

• Three key elements leveraged

• Recent developments in high temperature electronics

• Focused, low data volume measurements

• Novel operations scheme

• Science Objectives

1) Estimate moment exchange between planet

and atmosphere

2) Acquire temporal data to update global circulation models

3) Quantify near surface atmospheric chemistry variability

4) Technology demonstration for more capable future lander missions

• Operations Goals:

• Operate for a minimum of one Venus “daylight period” and day/night transition

(~60 Earth days)

• Take / transmit measurements periodically – timed for science need and to

maximize transfer to orbiter / data relay

LONG-LIVED IN-SITU SOLAR SYSTEM EXPLORER (LLISSE)


www.nasa.gov

TechnologyArea

HOTTech Tasks PI Organization

Packaging500°C Capable, Weather-Resistant Electronics Packaging for Extreme Environment Exploration

Simon Ang

University of Arkansas

Clocks &Oscillators

Passively Compensated Low-Power Chip-Scale Clocks for WirelessCommunication in Harsh Environments

DebbieSenesky

StanfordUniversity

GaNElectronics

High Temperature GaN Microprocessor for Space Applications Yuji ZhaoArizona State

UniversityComputerMemory

High Temperature Memory Electronics for Long-Lived Venus MissionsPhil

NeudeckNASA GRC

DiamondElectronics

High Temperature Diamond Electronics for Actuators and SensorsBob

NemanichArizona State

UniversityVacuum

ElectronicsField Emission Vacuum Electronic Devices for Operation above 500 degreesCelsius

LeoraPeltz

Boeing Corp.

ASICs & Sensors

SiC Electronics To Enable Long-Lived Chemical Sensor Measurements at the Venus Surface

Darby Makel

MakelEngineerin

g, IncPrimaryBatteries

High Temperature-resilient And Long-Life (HiTALL) Primary Batteries forVenus and Mercury Surface Missions

RatnakumarBugga

NASA JPL

RechargeableBatteries

High Energy, Long Cycle Life, and Extreme Temperature Lithium-SulfurBattery for Venus Missions

JitendraKumar

University ofDayton

Solar PowerLow Intensity High Temperature (LIHT) Solar Cells for Venus ExplorationMission

JonathanGrandidier

NASA JPL

Power Generation

Hot Operating Temperature Lithium combustion IN situ Energy and Power System (HOTLINE Power System)

Michael Paul

JHU/APL

Electric Motors

Development of a TRL6 Electric Motor and Position Sensor for VenusKris

ZacnyHoneybee

Robotics, Inc.

1

2

3

4

5

6

7

8

9

10

11

12

HOTTech Project Technology Areas

How Technology Areas Map to Spacecraft Systems

SPACECRAFT BUS

Mechanical Structures

Materials

Propulsion

Thermal Control

5, 6

COMMUNICATIONSHigh Power RF

Amplifiers

Antennas & Pointing

1Packaging

8PrimaryBattery

9Rechargeable

Battery

10

Solar Power

77

7

5Power Control

Electronics

4

11

Power Generation

12

Actuators/Motors

3

Optoelectronics & Cameras

2, 5, 6

3, 5, 6

POWER SYSTEMS

HOTTech Project Technology Areas


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Electronics


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High Temperature Electronics Advancements

• Unique capabilities have produced the World’s First Microcircuits at

moderate complexity (Medium Level Integration) that have the potential

for long-lived operation at 500˚C

• Circuits contain 10’s to 100’s of JFETs; An order of magnitude beyond a

few JFETs previously demonstrated in the last decade

• Enables a wide range of sensing and control applications at High

Temperatures

In-package signal conditioning for smart sensors

Signal amplification and local processing

Wireless transmission of data

A tool-box of signal conditioning, processing, and communications

circuits are being developed and demonstrated

R&D 100 Award 2018

Cross-sectional illustrations of NASA

Glenn 4H-SiC JFET-R devices with two

levels of interconnect. (a) Simplified

device structure drawing. (b) Scanning

electron micrograph of Generation 10

JFET source and gate region


www.nasa.gov

2017 NASA Glenn SiC JFET IC “Version 10”1+ year of operation in Earth air oven at 500 ° C Achieved

Version 10 ICs continue to set high temperature durability world records in T ≥ 500 °C Earth-atmosphere oven testing.

Complex ICs Operating more that 1 Year at 500 °C[1]

ICs Operating at World Record 961 °C[2]

[1] 2018 Int. Conf. High Temperature Electronics p. 71[2] IEEE Electron Device Letters vo. 38 p. 1082 (2017).

NASA GRC Electronics Development

2 or

4

Select

Logic

D Flip-Flops

Inactive

D Flip-Flop

High Frequency Ring Osc.

21-Stage Ring Oscillator

Clock

+ Output Buffers

Active

Address Decoder

Bit

4 X 4 RAM CellArray

Bitline Read/Write Drive Circuitry

with Sense Amplifiers

Output Buffers


www.nasa.gov

Electronics Demonstrate Operability in Simulated

Venus Conditions for 3 Weeks

• Previous operation of electronics in Venus missions

has been limited to hours at most due to the extreme

environment, and only in a protected

pressure/temperature enclosure.

• Unique capabilities have produced the World’s First

Microcircuits at moderate complexity with packaging

that have the potential for long-lived operation at

500˚C.

• Testing of these circuits took place in the Glenn

Extreme Environment Rig (GEER), which simulates

Venus surface conditions. A SiC high temperature 12-

transistor ring oscillator has been demonstrated at

Venus surface conditions in the Glenn Extreme

Environment Rig (GEER) for 21.7 days (521 hours)

with good stability throughout the entire test.

• This Venus surface demonstration of moderately

complex electronics was a significant world

record advancement. Testing in Venus conditions

was ended after 21 days for scheduling reasons.

A SiC high

temperature

12-

transistor

Ring

Oscillator

High Temperature Ring Oscillator Continues

Stable Operation in these Venus Simulated

Conditions for 521 hours

Glass-basedpressure seal

Ceramicsubstrate

3mm x 3mmSiC Chip

Ni alloy wiresin fiberglass

sleeves

Before Venus test

After Venus test

SiC High

Temperature

Electronics Before

And After Testing

in Venus Surface

Conditions:

Rugged Operation

for Extended

Durations


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60-Day Venus Environment IC Test (in GEER)1,2

Two IC Version 10 ÷2/÷4 Clock ICs (175 JFETs/chip) successfully operated inGEER Venus surface conditions for 60 days duration.

Before GEER After 60 days GEER

1Neudeck et al., IEEE J. Electron Devices Soc., vol. 1, p. 100 (2018).2Chen et al., Proc. 2018 Int. High Temperature Electronics Conf.


www.nasa.gov

IC Version 1115x8 (120) bit RAM

~ 1000 JFETs4.65mm x 4.65 mm Chip, 32 I/O Bond Pads Shared (Tri-State) Read & Write Data Bus

IC Version 10 4x4 (16) bit RAM 195 JFETs

3 mm x 3 mm Chip, 32 I/O Bond Pads Separated

Read & Write Data Busses

Comparison of Version 10 vs Version

11 JFET IC Prototype RAM Chips

On-Going Work to Increase Complexity and Capability

CoIs: Stephen Goodnick, Franz Koeck, Brianna Eller,

James Lyons/Arizona State University; Srabanti

Chowdhury/UC-Davis;

Hot Operating Temperature Technologies

Key Milestones:

• Diamond PIN diodes for actuator applications operating >500°C with 50V blocking and 1A forward.

• Diamond bipolar junction transistors (BJT) for actuator applications operating > 500°C with 50V blocking and 1A forward.

• Diamond bipolar junction transistors (BJT) for sensor applications with high linearity, low noise at >500°C.

Target:

Diamond electronics for actuator and sensor applications at high temperatures (>500°C) for Venus and solar missions.

Science:

The Decadal Survey identifies future missions including Mercury/Venus seismic networks and Venus sample-return. Key technological components of such missions include high-temperature (>500°C) survival and long-duration high-temperature subsystems.

Objectives:

• Develop, test and simulate diamond PIN diodes and bipolar junction transistors (BJT) for actuator control and low noise sensor amplification operating >500°C.

• Growth of diamond epitaxial structures eliminating defect structures that degrade device performance.

• Develop strategies for low resistance contacts and stable surface passivation.

• Simulate device operation, stability and degradation for high temperature operation.

• Identify specific mission objectives that would be impacted by the diamond electronics, and develop device specifications.

Schematic of a diamond PIN diode structure and a simulation of the current density in a

diamond BJT operating at 500°C

High Temperature Diamond Electronics for Actuators and Sensors

PI: Robert J. Nemanich/Arizona State University


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Packaging


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High-T packaging1,2 (32 pins)

• Package durability and leakage characterized.• Packages NOT sealed, chips are subjected to ambient

atmosphere (Earth or Venus) during high temperature testing.

1L. Chen, et al., Proc. IMAPS High Temperature Electronics Conference, 2016, pp. 66-72.2P. G. Neudeck, et al., IEEE Electron Device Lett. 38 (2016) 1082-1085.

Key Milestones:

• High temperature die metallization determination

• Anti-fouling coating selection & evaluation

• Chip integration selection & evaluation

• Substrate integration evaluation

• Package construction and environmental evaluation

• Pre-mechanical chip integration analysis

• GEER testing of packaged components

• Post-mechanical chip integration analysis

Target: Extreme environment package providing flexible I/O and related integration processes.

Science:•Deeper understanding of survival/degradation behavior of die attach, metal interconnect, and housing materials in extreme conditions (500°C, chemically corrosive conditions)

Objectives:

•Leverage existing wide bandgap devices (e.g., SiC and GaN diodes) with high-temperature metallization.

•Develop high-temperature packaging using 500°C capable die attach and metal interconnect technology on ceramic substrates.

•Integrate nanotextured anti-fouling films onto housing surfaces.

•Perform thermal and chemical exposure tests on packaging materials and actual packaged devices using high-temperature furnaces (Stanford) and relevant simulation pressure vessels (NASA and University of Arkansas).

•Analyze experimental data and make specific recommendations to NASA for selection of packaging materials and design architectures to realize HOTTech-relevant systems.

CoIs: Stanford; Dr. Debbie Senesky, ExtremeEnvironment Microsystems Laboratory (Xlab)

H SO2 4

LTCC substrate HTCC-feedthrough

black Al O2 3

SiC diode

Kovar lidResistance

SealingAg sintering

die attach

Base W/Cu

High Temperature Operating Technologies

500°C Capable, Weather-Resistant Electronics Packaging for Extreme Environment Exploration

PI: Simon Ang / Univ. of Arkansas

Nanotextured Anti-fouling Coating

High-temperature Weather- resistant

Electronics Packaging


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Sensors


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LLISSE SensorsBroad Array Sensor Technology for Venus Applications

Leveraged From Aeronautics Development

• Active development of harsh environment smart sensors

systems for engine test stand, health management, and

intelligent engine systems

• Demonstration/Application in Multiple

Applications/Commericalized System

Development Approach:

• Miniaturized sensor systems produced by microfabrication

techniques and high temperature compatible materials

• Parallel Development of Multiple Sensor Types

• Pressure

• Temperature

• Wind (3 directions)

• Multiple Chemical Species

• Radiance

• Each sensor has targeted specifications and associated

electronics requirements

Status

• Multiple sensors interface with electronics demonstrated in

Venus Simulated Conditions.

• Demonstration of reliable, responsive SO2 detection for 60

days in Venus simulated conditions

Courtesy of D. Makel, Makel

Engineering, Inc.

Chemical Sensor Array for GEER chamber Simulated Venus Surface testing

High Temperature Pressure Sensor

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Date and Time

SO2 PPM

Gas BoostsSignal Drop At During Cooling

Down Due to Power Limit to

Sensor

SOx Sensor During 60 Day GEER Test

Type Date GEER GAS ANALYSIS SENSOR D ppmPre-boost 8/25/2017 89.4 84.7 4.7

Post-boost 8/28/2017 132.2 126.9 5.3

Pre-boost 9/1/2017 82.6 83.3 -0.7

Post-boost 9/1/2017 178.0 180.9 -2.9

Pre-boost 9/11/2017 76.7 83.5 -6.8

Post-boost 9/11/2017 186.0 186.8 -0.8

Pre-boost 9/27/2017 64.8 71.4 -6.6

Post-boost 9/27/2017 177.2 183.2 -6.0

Pre-boost 10/2/2017 139.8 135.6 4.2

Post-boost 10/4/2017 161.6 159.5 2.1

Post-boost 10/18/2017 80.0 88.8 -8.8

Post-boost 10/20/2017 70.0 80.9 -10.9

Chemical Sensors Progress:

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Sig

na

l C

ou

nts

(1

2-b

it A

/D

)

GEER 14 Day Test HF Sensor with SiC Amp - raw cnts

HF injections to appoximately 2.5 ppb

Start of Chamber Cooldown

To 150 C

• HF sensor operated with SiC

amplification electronics

throughout May 2018 GEER test

• Internal SiC signal

transduction and amplification

electronics

• External A/D electronics and

data recording

• External sensor temperature

control electronics

• External sensor bias source

• Sensor movement with HF boosts

• No loss of sensor signal

throughout test

SiC Electronics Packaging

SiC Electronics Combined With Chemical Sensor for GEER Testing

Au Paste Reinforcement

Gen I0 Electronics

GEER Test Probe

SiC Diode Chemical Sensor

Au Wire Bonds

Approved for public release

Courtesy: Tom Pike

MEMS seismic event sensor

Sensors images – Courtesy: NASA GRC

Heat Flux sensor - Courtesy: Mike Pauken

Courtesy of D. Makel,

Makel Engineering, Inc.

SAEVe: The Instrument Suite

Rationale for Instruments / Sensors

A) Core science centers around long term

measurements to obtain meteorological and

seismic data over 1 Venus solar day (120

Earth days)

B) This is possible with high temperature, low power,

low data volume instruments / sensors

•Instrument payload supports this constraint

Instrument set includes:

• A 3-axis micro-machined Micro-Electro-Mechanical Systems

(MEMS) seismometer (0.3 kg)

• Meteorological sensor suite (temperature, pressure, wind

speed & direction, solar radiance, atmospheric chemical

species abundances), and solar position sensors (0.7 kg)

• Two COTS Cubesat cameras (0.1 kg each )

• Heat Flux instrument (0.3 kg)


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Communications


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LLISSE Communications

History of Cutting Edge Development in High Temperature

Wireless Communications

• Wireless Signal Spectra For High Temperature Seismometer

Sensor Displacements Demonstrated (2012)

• Demonstrated Wireless Pressure Sensor At 475ºc Including

Pressure Sensor, Sic Circuitry and Wireless Circuit (2013)

DevelopmentApproach:

• Activities include Venus relevant development of antennas,

transmitters and other components

• Increasing Capabilities and Complexity of High Temperature

Electronics Circuits Increase Communications Capabilities

• Targeted Operation of Communication System from 50 to 150 MHz

by 2021.

Status

• Next Generation High Temperature Communication Circuits Have

Been Fabricated and Are Being Evaluated

• Development of circuit hardware architecture for higher frequency

communications systems on-going

• Baseline LLISSE Antenna Materials and Design Approach Identified

and Initial Material Testing In Venus Simulated Conditions Begun

• Proof-of-Concept Demonstration of Integration of Communications

Circuits/Signal Processing Circuits Planned in Next Year

Wireless seismometer and circuit

in an oven at 500ºC

Wireless Pressure Sensing

Circuit)

Passively Compensated Low-Power Chip-Scale Clocks for Wireless Communication in Harsh Environments

PI: Prof. Debbie G. Senesky (Stanford University)

• Year 1:

• Year 2:

1.) Demonstrate resonator with Q above 2,000 2.) Achieve temperature stability below 10 ppm 3.) Perform characterization of discrete resonators and oscillator resonator array

1.) Demonstrate resonator with Q above 5,000 2.) Achieve temperature stability below 1 ppm 3.) Perform high-temperature characterization of oscillator resonator array

Target: Utilize 1000°C capable InAlN/GaN electronic device architectures to mature high-temperature stable clock technology.

Science:

•Increase the duration and scope of many proposed NASA missions to hot planets and bodies (e.g. Venus, Mercury, or Gas Giants).

•Enable stable collection/transmission of scientific data from any probe, lander, explorer, or sensor to be transferred to main spacecraft.

Objectives:

•Adapt existing AlGaN/GaN and AlN micromechanical bulk-mode resonator designs to the InAlN/GaN platform using multi-physics modeling tools.

•Nanofabricate lattice-matched InAlN/GaN micromechanical resonator arrays with high-temperature metallization, passive temperature compensation, and various film doping concentrations to achieve high-temperature operation.

•Perform in-situ high-temperature laboratory characterization (up to 600°C at various pressures) to quantify temperature-dependent frequency response.

Schematic image of an envisioned rover on the hot surface of Venus communicating collected scientific

data with robust radio transmitter chip.


Key Milestones:

CoIs; Dr. Mina Rais-Zadeh (NASA Jet Propulsion Laboratory


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Power


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LLISSE Power

Configuration

Volume: 1.07 liters

Weight: 2.83 kg

2.39 Ampere-Hours

95.6 Watt-Hours @ 40 V

89 Watt-Hour/liter

Performance Summary

Voltage (max./min.): +25 V/ 0.0/-25 V

Current: 0.2 with pulses up to 12A

Life: 60 Earth days

Temperature: + 4650C

Environment: Venus Surface @ 90 Bar

CoIs:i) Michael Pauken (JPL); ii) William West (JPL) iii) Dharmesh Bhakta (Eagle Picher Tech)

High Temperature-resilient And Long-Life (HiTALL) Primary Batteries for Venus and Mercury Surface Missions

PI: Ratnakumar Bugga / NASA-Jet Propulsion Laboratory


Target: Surface missions to Venus, Missions to Mercury, or the deep atmosphere of gas Giants.

Science:Being inherently stable at 500oC and high CO2 pressures (92 bar) and having high specific energy, these batteries will enable a long-term in-situ Venus missions for >30 days (vs <2h with the state of art batteries)Venus surface geology, tectonic activity and composition of Venus and Mercury.

Objectives:

• Develop an enabling advanced primary battery technology resilient to the high-temperature environments of Venus surface, Mercury, or the deep atmosphere of gas Giants and operational for 30 days at 500oC (and 92 bar pressure) to enable their robotic exploration.

• Improve the energy densities of these batteries for powering in-situ missions for >30 days.

• The performance targets include: specific energy of >150 Wh/kg, energy density >200Wh/l, long calendar life (>5y) and low self- discharge (<1%/day) at 500oC.

• Batteries will be lightweight (3X vs. SOA) and compact (4X vs. SOA) and will support Venus/Mercury surface missions over longdurations(>30 days vs <2h for SOA)

Low Intensity High Temperature (LIHT) Solar Cells for Venus Exploration Missions

PI: Jonathan Grandidier/JPL

Key Milestones:

•Fabrication of preliminary LIHT solar cell (MicroLink/UIUC)

•Develop LIHT solar cell performance models (CalTech)

•Test data and analysis of advanced LIHT at 300C demonstrating performance under Venus solar spectrum (JPL)

Replace this box with figure(s) illustrating and clarifying the concept

Low Intensity High Temperature (LIHT) Solar Cell. The LIHT solar cell will enable survival and optimize performance in the Venusian environment.

Target: The overall objective is to develop Low Intensity High Temperature (LIHT) solar cells that can function and operate effectively in the Venus atmosphere at various altitudes, and survive on the surface of Venus where the temperature reaches 450-500°C.

Science:We are developing a dual-junction high-temperature GaInP/GaAs solar cell to satisfy the extreme Venus environmental requirements. The novel features of the proposed cell include:•high bandgap semiconductor materials (GaInP/GaAs), that are optimized to capture solar irradiance efficiently at Venus.•high-temperature tunnel junctions.•high-temperature solar cell contacts.•anti-reflection coatings.•Al2O3 corrosion protection coatings.•Adjust size of text box as required

Objectives:•Demonstrate technical feasibility of a LIHT solar cell•Fabrication of a LIHT cell and demonstrate LIHT performance goals

CoIs: Alex Kirk, Mark Osowski/Microlink Devices;Minjoo L. Lee/UIUC; Harry Atwater/Caltech



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Actuation

Co-Is: Jeffery Hall, Jay Polk/JPL; Fredrik

Rehnmark, Cody Hyman/Honeybee Robotics

Objectives:

•Design, build and test an electric motor and

position sensor compatible with Venus surface

environment (CO2 at 462C, 90 bar pressure).

•Document fabrication and screening test

procedure.

•Characterize high temperature reduction in motor

torque and efficiency by dynamometer testing.

Compare with analytical predictions.

•Perform motor life test.

•Mature HT motor technology from TRL5 to TRL6.

Key Milestones:

• Month 1-3: Perform analysis to size HT

motor.

• Month 4-6: Build HT motor.

• Month 7: Perform dynamometer and life

test.

• Month 8-12: Integrated demonstration at

VTP.

Target:. Scientific mission to surface of Venus or

similar high temperature, high pressure (HTHP)

environment

Science:

•Regolith sample acquisition and transport.

•Pointing of cameras and antennas.

•Robotic manipulation.

•Mobility.

ANALYSIS: Motor simulations performedwith Low-Frequency Electromagnetic FieldAnalysis Software.

DEMONSTRATION:HTmotor and position sensor installedin Venus rock sampling drill (left)and high pressure blower (right).

TEST: HT dynamometer testing.


Development of a TRL6 Electric Motor and Position Sensor for Venus

PI: Kris Zacny/Honeybee Robotics


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SUMMARY

• Venus Surface Exploration Has Unique Technical Challenges Due To The

Extreme Environment

• A Range Of Harsh Environment Technologies Are In Development To Enable

Long Life Surface Missions

Electronics, Packaging, Communications, Power, Actuation

• This presentation gave a brief sampling of some of the Technologies in

Development related to the LLISSE and HOTTech Projects

• LLISSE plans a demonstration of integrated technologies for a probe system

with communication in 2021, moving towards an Engineering Model by 2023

• HOTTech awarded 12 awards with a broad portfolio of technologies needed for

a long-lived spacecraft or surface lander on Venus

Many have shown progress to demonstrate functional operation at realistic

environmental conditions.

GEER (MiniGEER) testing planned for several of the technologies

HOTTech-2 is pending approval of budget, and if selected, will start in 2021

• Recent advances have been significant and the prospect of long-lived

missions on the Venus surface is becoming increasingly viable in the next

decade


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Backup


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Title: High Energy, Long Cycle Life, and Extreme Temperature Lithium-Sulfur Battery for Venus Missions

PI: Jitendra Kumar/University of Dayton Research Institute (UDRI),Dayton, OH

Target: Venus surface exploration

Science:•In-situ surface studies of rarely explored planet (Venus).•Understanding high temperature battery materials and interfaces,•Understanding design and performances of a high temperature rechargeablebattery.

Objectives:

Objective is to enable longer and safer NASA Venus mission by developing rechargeable battery with following targeted features:

•Specific energy density = 300 Wh.kg-1,

•Cycle life with 100% DoD = 100-150 cycles,

•<10% self-discharge,

•Operation temperature up to 500°C

•High electrical and thermal safety.

CoIs: Priyanka Bhattacharya (UDRI); Yu Zhu (University of Akron), & Guru Subramanyam (University of Dayton).

Proposed Layout of molten Li-S Battery using Li or lithiated Si anode, S cathode encapsulated in 3D ceramic (e.g. LAGP or LLZ, or LGPS) and dense, flat, solid ceramic (e.g. LAGP or LLZ, or LGPS) electrolyte. (UDRI Propriety).

Key Milestones:

•M1: Physical (morphology, structure, chemical composition, etc.) and thermal characteristics of LAGP electrolyte interfaced with Li and S compatible materials in presence of Li and S at 25, 180, 400 and 500°C,

•M2: Cell design and data on energy density, power density, cycle life of

molten LSB based on LAGP at 400-500°C,

•M3: Physical (morphology, structure, chemical composition, etc.) and thermal characteristics of LLZ electrolyte interfaced with Li and S compatible materials in presence of Li and S at 25, 180, 400 and 500°C,

•M4: Report on cell design and data on energy density, power density, cycle life of molten LSB based on LLZ at 400-500°C.



www.nasa.gov

Evolving “Handbook” of What Works in Venus Ambients

Devices Materials Outcome

Electronics Packaging Pb PbS

Al2O3 No reaction

Insulation CaO CaSO3, CaSO4

SiC Electronics Pt PtS; fibers when present as thin film

Pt (in the presence of Au) PtS spheres

Au No reaction, but mobile

Ir No reaction, but mobile

SiC No reaction

SiO2 No reaction

Feedthrough Materials Cu Cu2S crystals

Ni NiS crystals

CuBe Cu2S crystals; Cl found on surface

SiC Pressure Sensor Kovar (Ni-Co-Fe) NiS, FexOy

AlN No reaction

Ag-Cu Braze Segregation into Cu2S and Ag; Ag mobile

GEER Components Inconel 625 (Ni-Cr-Mo-Fe) NiS, CrxOy

304 SS Mirror finish, low corrosion rate

Al foil/Mg dopedMgO on surface, MgF inner layer,

Al bulk no reaction

New Materials Sputtered Aluminum Reacts with HF to form AlF3

Titanium Oxide on surface decreasing into bulk

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2017EA000355

a brief overview of high temperature technologies relevant

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