Piszczor, Michael F., Jr.

NASA Technical Reports Server

National Aeronautics and Space Administration
www.nasa.gov
Photovoltaic Technology 
Development and Capabilities at GRC
Michael F. Piszczor, Jr. 
Photovoltaic Technology Lead
Photovoltaic and Electrochemical Systems Branch
USAF/SMC OCS Briefing at NASA GRC
January 17, 2018
https://ntrs.nasa.gov/search.jsp?R=20180004614 2019-08-31T15:35:25+00:00Z
National Aeronautics and Space Administration
www.nasa.gov
Nanomaterials and Nanostructures 
for Space Photovoltaics
Advanced 
Blanket and 
Array 
Technologies
Solar Cell Measurement and 
Performance 
Evaluation 
Extreme Environment Operation of 
Solar Arrays
Photovoltaic (PV) Areas of Expertise
High Efficiency III-V 
Photovoltaic 
Development 
Radioisotope-based Direct Energy 
Conversion (Thermophotovoltaic
and Alpha/Beta-voltaic Technology)
Solar Cell Air Mass Zero Calibration
Research and development 
on a wide variety of solar 
cell, blanket component, and 
array concepts to support 
NASA missions and 
aerospace technology needs.
Solar Array Arcing and Charging 
Effects
National Aeronautics and Space Administration
www.nasa.gov
PV Supports Broad Range of TRL Activities
TRL 2-4 TRL 7-9TRL 5-6
Examples:
• NASA Institute for 
Advanced Concepts (NIAC) 
studies, Small Business 
Innovation Research 
(SBIR) contracts, student 
and faculty fellowships, etc.
• Focused on PV materials & 
novel designs for improved 
efficiency, radiation resis-
tance, temp. extremes, etc.
• High temp. cells, perov-
skites, low-cost substrates
Examples:
• Advanced Technology 
Performance, Reliability, and 
Environmental Interactions 
R&D and Evaluation
Examples:
• Support NASA Missions 
Through Technical Expertise
• Evaluate Flight Data for 
New Technology
• Development of Standards 
and Guidelines
InAs Quantum Dots in GaAs cells
Thermal balance & arcing of 
blanket technology
Accurate cell efficiency measurements
SCARLET 
array on 
Deep 
Space 1
Mars Rover 
Experiments
National Aeronautics and Space Administration
www.nasa.gov
Expert physicists, chemists, and engineers with 
extensive experience in solar cell fabrication and 
solar array operation within the space environment. 
World experts in materials growth, device 
fabrication, cell measurement and characterization, 
and coupon/array environmental testing.  Partners 
range from universities, non-profit organizations and 
small/large businesses to various NASA Centers and 
other Government agencies. 
X25 Solar Simulator 
and new LED Simulator 
for accurate measure-
ments of solar cell 
performance
Lear upgraded to ER-2 aircraft for
Calibration Flights to provide cell 
standards for the aerospace 
community
Thermal Balance Testing 
for Lightweight Blankets
PIF (Plasma 
Interactions 
Facility) for 
testing of solar 
arrays within a 
space 
environment
OMVPE 
Reactors for 
growth of high 
efficiency solar 
cells
World Class Capabilities in PV
ER-2 
Aircraft   
National Aeronautics and Space Administration
www.nasa.gov
NASA Thrusts in Power Technology Development
1) Power for Human Surface Missions
Stationary Power:
40 kW continuous power, day & night
High system specific power >5 W/kg
Nuclear fission or PV with energy storage
Human-rated (safety and fault tolerance)
Robotically-deployed (pre-crew arrival)
Survivable for multiple crew campaigns >10 yrs
Mobile Power:
6 to 10 kW rechargeable power, up to 120 kWh
Advanced batteries/fuel cells >300 Wh/kg, >200 cycles
Maximum commonality with other surface assets
Grid-compatible (with stationary power)
Both: Mars gravity, wind, dust, CO2, temperature, diurnal period
2) Power for Electric Propulsion
Near Earth Systems:
30 to 50 kW solar array wings >100 W/kg
Compact array stowage >40 kW/m3
High deployed strength >0.1g and frequency >0.1 Hz
High operating voltage >160V, PPU-compatible
Long life >7 yrs with reuse
Mars and Beyond:
100 to 300 kW solar array wings >150W/kg
Radiation tolerant solar cells
Compact array stowage >60 kW/m3
1 to 5 MW fission reactors <5 kg/kW
High operating voltage >300V, PPU-compatible
Long life >5 yrs (Earth to Mars)
3) Power for Robotic Science Probes
Orbiters, Landers & Rovers:
Power levels from 100 to 600 W at EOM
Possibly kWs for ice melting, comm relays, EP
Very long life >10 yrs and high reliability
Low mass power systems >5 W/kg 
High performance RPS/fission >15% eff.
Low intensity/low temperature PV >25% eff.
Advanced batteries >300 Wh/kg, >200 cycles
Extreme environments (low/high temperature,
low/high solar intensity, high radiation)
4) Power for Small Spacecraft
Near Earth Systems:
Power levels from 100 to 500W
Body-mounted or deployable solar arrays >200 W/kg
Advanced batteries >200 Wh/kg, >200 cycles
Compatible with 2U to 24U Cubesat platforms
Highly integrated systems with shared structure
Deep Space Systems:
Power levels from milliwatts up to 60W (nuclear)
Small RPS using multiple RHUs or single GPHS
Advanced conversion (TE, Stirling, Alpha/Beta-voltaic) >15% eff
National Aeronautics and Space Administration
www.nasa.gov
Mars Surface PV Array Concepts Evaluated
6
National Aeronautics and Space Administration
www.nasa.gov
Mars Surface Lander Baseline Design
Using Six Solar Array Wings
7
Surface array design based on Compact Telescoping Array concept
1 degree 
of freedom 
rotation
10-m 
Lander
1000 m2 total solar cell area. Array spacing allows cargo 
access from 2 sides.
55 deg
National Aeronautics and Space Administration
www.nasa.gov
Proving Ground Or
Split Mars Architecture
Hybrid Mars 
Architecture
• 50-kW Solar Array System
• 40-kW EP System
• 5-t class Xenon Capacity 
with Refueling Capability
• 13-kW EP strings
• 190-kW Solar Array
• 150-kW EP System
• 16-t class Xenon Capacity
• 13-kW EP strings
• 400-kW class Solar Array
• 300-kW class EP System
• 16-t class Xenon Capacity
• 30-kW class EP strings
Initial SEP Capability
(SEP Technology Demo)
Power for Solar Electric Propulsion (SEP)
National Aeronautics and Space Administration
www.nasa.gov
Electric Propulsion (EP) Solar Array Systems
• Novel 20 kW-class solar arrays designed & built to advance TRL from 4 to 5+ for SEP missions; 
extensible to 300 kW class (>$12M invested on two contracts)
• Testing included:  stowed acoustic/random vibration, thermal extreme vacuum deployments, 
deployed strength/stiffness, deployed structural dynamics in ambient & vacuum, PV coupon 
plasma interactions up to 600 V in ambient and EP plasma plume
• Improvement to state-of-the-art:  power, voltage, mass, stowed volume, deployed 
strength/stiffness, radiation hardness
ATK MegaFlex DSS Roll Out Solar Array (ROSA)
2015 Recipient: Rotary National Award for Space Achievement – Stellar Award
National Aeronautics and Space Administration
www.nasa.gov
• Higher power provides path to increased 
capabilities
 More instruments, increased duty cycles
 High rate communications, real time 
tele-operations, in-situ data analysis
 Sufficient on-board power for subsurface 
science (e.g. ice melting)
 Integration with EP for lower launch mass, 
and multiple targets with single spacecraft
• Upcoming mission applications
 Europa Clipper/Europa Lander
 New Frontiers 2024, Discovery 2028
 Future Flagships:  Titan Saturn System 
Mission, Uranus Orbiter Probe, Neptune 
Systems Explorer, Saturn Ring Observer, 
…
Power for Robotic Science Probes
• Key for robotic science is long life, reliable 
power
 Plutonium-powered RTGs have been staple 
for >40 yrs but fuel availability, integration 
costs, schedule risk, & launch safety are 
impediments
 Solar power is starting to win power trades 
(e.g. JUNO, Solar Probe Plus, Europa 
Clipper)
• Expected end-of-mission power requirement 
is 100 to 600 We
 Possibly kWs for ice melting, 
communication relays, electric propulsion
 Need low mass power systems >5 W/kg 
and high conversion efficiency >15% 
nuclear, >25% solar
Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
National Aeronautics and Space Administration
www.nasa.gov
Extreme Environments Solar Power (EESP)
• EESP Project seeks to develop solar cell/solar array technologies for mission 
applications in high radiation and low solar flux environments
– Investigate PV cell chemistry improvements for low intensity, low temperature (LILT) 
environments
– Investigate array configuration options that improve performance in extreme environments 
– Increase array efficiency & life; decrease system mass & cost
• Four Base Contracts Awarded (July 2016)
– Concentrator Solar Power Systems for Low-intensity Low Temperature and High Radiation Game 
Changing Technology Development, Orbital ATK
– Transformational Solar Array for Extreme Environments, JHU/Applied Physics Lab
– Micro-Concentrator Solar Array Technology for Extreme Environments, Boeing
– Solar Array for Low-intensity Low Temperature and High-Radiation Environments, NASA JPL
• Selection of Two Contract Options for Continued Development after Base Contracts
Key Performance Parameters
Performance Parameter State of the Art Threshold Value Project Goal
*Beginning of Life (BOL) Cell Efficiency (%) 30 33 35
*End of Life (EOL) Cell Efficiency (%) 21 25 28
Specific Power (W/kg) 70 100 120
Stowed Volume (kW/m3) 15-30 45 60
*at the following mission conditions:  -125°C, 4E15 1MeV e/cm2 Radiation, 50 W/m2 Solar Intensity
National Aeronautics and Space Administration
www.nasa.gov
EESP Option 1 Contract Awards
Orbital ATK
Point-focus lens concentrator blanket compatible 
with the Compact Telescoping Array (CTA) 
platform utilizing state of the art ZTJ solar cells
Johns Hopkins Univ. Applied Physics Lab
DSS Roll Out Solar Array (ROSA) equipped with 
Flexible Array Concentrator Technology (FACT) 
and Inverted Metamorphic solar cells
National Aeronautics and Space Administration
www.nasa.gov
Near Earth Technology Needs:
• Power levels from 100 to 500W
• Body-mounted or deployable arrays >200 W/kg
• Advanced batteries >200 Wh/kg, >200 LEO 
cycles
• Compatible with 2U to 24U CubeSat platforms
Deep Space Technology Needs:
• Power levels from milliwatts up to 60W 
(nuclear)
• Small RPS using multiple Radioisotope Heater 
Units (RHU) or single General Purpose Heat 
Source (GPHS)
• Advanced conversion, e.g. thermoelectric, 
Stirling, thermo-photovoltaic, alpha/beta-
voltaics >15% eff
Power for Small Spacecraft
Small Spacecraft Power
• Growing trend to fly greater number of small 
missions versus one or two large missions
• Small satellites can provide cost benefits and 
greater access to space 
• Advanced power technologies are crucial to the 
small satellite and CubeSat market segment
• Power system improvements can increase 
available power, extend mission life, and/or allow 
greater payload mass
Current State of the Art:
• Commercial solar arrays with >28% efficiency
• Commercial Li-ion batteries at ~150 Whr/kg
• Commercial plug and play power distribution 
boards and electrical controllers
• Poor reliability – high failure rates
Power Challenges:
• Highly integrated systems with shared structure 
and thermal management
• Improved performance, increased reliability, 
decreased recurring cost
• Low cost power options for beyond Low Earth 
Orbit
13
National Aeronautics and Space Administration
www.nasa.gov 14
• Major US cell suppliers are SolAero Technologies and Spectrolab
– Nominally 30% in-space conversion efficiency
– Gallium arsenide-based multijunction (3-junction) solar cell technology
– Fully space-qualified
– Designed for End-of-Life (EOL) performance
(within the space radiation environment)
– VERY EXPENSIVE (compared to terrestrial solar cells)
Industry Diversification into Terrestrial Photovoltaics 
• Adaptation of space cell technology for terrestrial PV 
systems 
– Minor changes to space cell design, but essentially the same 
technology
– Addressed high cell cost thru concentrator applications (> 1000 
suns)
Terrestrial 
concentrator cells
State-of-the-Art Space Photovoltaics 
Space solar cell
National Aeronautics and Space Administration
www.nasa.gov 15
• Application of low-cost solar array blanket manufacturing methods and 
terrestrial solar cell technology for space missions
– Automated manufacturing and modularity
– SpaceX use of silicon PV terrestrial technology for short duration missions
– Focus is on ”lower cost” cell technology
– NASA has conducted in-space flight experiments of terrestrial PV to evaluate long-
term survivability under NASA mission requirements (with mixed results)
• Use of lower cost epitaxial grow techniques for gallium arsenide-based 
higher efficiency solar cells 
– Hydride Vapor Phase Epitaxy (HVPE) growth techniques being developed at 
National Renewable Energy Laboratory (NREL)
• Renewed interest in perovskite solar cell technology
– Potential for high efficiency terrestrial technology at lower fabrication costs
– Recent test results indicate potential for in-space radiation hardness
Terrestrial PV Technology of Interest to NASA
National Aeronautics and Space Administration
www.nasa.gov 16
Current uses of MLD ELO
cell technology
• MicroLink Devices (MLD)
– Uses GaAs multijunction solar cell technology similar to space
– Focus is on reducing solar cell cost (> 50%) while maintaining high efficiency
– Epitaxial Lift Off (ELO) technique used to reduce mass and cost
– Wafer substrate is recycled/reused to reduce substrate cost
– Current terrestrial uses include increasing flight endurance of Raven UAV and 
battery recharge capability in the field.  Space applications involve substrate 
reuse to reduce cost/mass and ”rollable” blankets.
– Mission use requires flight qualification of technology
– Primarily via SBIR funding
• Starshine-3 Flight Exp.
– Integrated Micropower
Systems (IMPS):  were 
successfully flown 
aboard Starshine-3 
and provided 
continuous power for 
on-board temperature 
sensors.
Examples of Terrestrial PV for Space Applications
Starshine-3
National Aeronautics and Space Administration
www.nasa.gov 17
ENTECH High-Voltage SunLine on Mt. Haleakala (Maui)
Power source used in NASA GRC-funded Power Beaming Experiment
Each Concentrator Module Uses a 3 m2
Color-Mixing Lens to Focus Sunlight at 
26X Concentration onto a 
Boeing/Spectrolab Triple-Junction Cell 
Receiver
Measured IV Curves for Both Modules – Note that the 
Better Module (670 W) Had to Have Its Heat Sink 
Insulated to Enable this Measurement
Boeing Developed the Photovoltaic Receivers for this Test
– the First-Ever Terrestrial Multi-Junction-Cell Array Over 1 kW
National Aeronautics and Space Administration
www.nasa.gov
Dual-Use Technology:  From Ground Technology to Space
Technology to Improved Ground Technology Winning R&D 100 Award
Improved ground photovoltaic concentrator technology called SolarVolt uses small (15 cm 
wide) Fresnel lenses focusing onto small (0.75 cm wide) silicon cells as shown in array on left 
with older large lens technology on right.  SolarVolt is much lighter and cheaper than the old 
large lens technology, due to lessons learned from the Stretched Lens Array for space.  
SolarVolt won an R&D 100 Award in 2012 for NASA GRC and Entech Solar.
National Aeronautics and Space Administration
www.nasa.gov
In Summary
• GRC covers a wide range of PV technologies and TRL levels
• Focus is on NASA-specific space PV technology 
development with unique in-space mission requirements 
• Leverage existing commercial space PV where possible
• Monitor terrestrial PV developments for NASA use where 
appropriate
• Collaborate closely with Air Force, Navy, and OGA efforts
• Interagency Advanced Power Group, Small Business 
(SBIR) contract reviews, grant/student programs, etc.
• Tours on advanced cell/array development and solar cell 
measurements and calibration are available upon request


Photovoltaic Technology Development and Capabilities at GRC

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server