by Douglas Messier
Managing Editor
NASA has selected five research and development projects for funding that are focused on improving the performance of solar sails, which use solar photons (sunlight) to propel themselves.
NASA selected the five projects under the space agency’s Small Business Technology Transfer (STTR) program, which partners companies with academia. Each Phase I award is worth up to $150,000.
Gossamer Space of Lansdale, Pa, and the University of Notre Dame in South Bend, Ind., are developing an advanced polyethylene/grapene nanocomposite film.
“The polyethylene/graphene nanocomposite film we are adapting for use in space could dramatically improve the performance of solar sails, solar cells and deorbiting devices. If made into a cable form, the extremely high specific strength can also improve the performance of tether and centrifugal launch launch applications,” the partners said in the proposal summary.
NASA selected two projects focused on solar sail antenna technology. Nexolve Holding Company of Huntsville, Ala., and Utah State University in Logan have teamed to develop a new patch antenna array.
“A new patch antenna array composed of thin-film materials is proposed to create a significant improvement in the specific mass and specific volume of the antenna array. This innovation will enable the combination of the patch antenna array with a solar sail to address the need for a High Gain Antenna (HGA) option for deep space solar sail missions,” the proposal summary said.
Nanohmics of Austin, Texas and Texas State University in San Marcos are working on a printed ultra-wideband phased array antenna (PAA).
“Nanohmics in collaboration with Texas State University intends to develop a miniaturized, flexible, and multiband PAA architecture using miniaturized, ultra-wideband antennas printed on a common solar sail material (i.e. Kapton),” the proposal summary said. “This will include scaling an existing antenna design to bands of interest and developing a high-power, fully-printed electronic switching architecture to advance the power handling and high-frequency operation in these printed active PAAs.”
SSS Optical Technologies and Oakwood University, which are both located in Huntsville, are working together on an advanced coating capable of blocking ultraviolet (UV) light for photovoltaic (PV) cells embedded on solar sails.
“SSS Optical Technologies, LLC (SSSOT) together with HBCU Research Institution (RI) Oakwood University (OU) and subcontractor Regher Solar, Inc. (RSI) propose to develop the Polymer Anti-damage Nanocomposite Down-converting Armor (PANDA) coating of solar sail-embedded PV cells that, in addition to blocking UV and ionizing radiation and being UV stable, flexible, and light weight, converts UV into visible radiation that matches the responsivity spectrum of the PV cell. This makes possible to generate extra electricity thus improving the overall PV conversion efficiency by up to 5%,” the proposal summary said.
Opterus Research and Development of Loveland, Colo. and the University of Colorado at Boulder are teaming to to develop a solar sail tubular mast.
“Solar Sail Tubular Mast (SSTM) is a lightweight version of Opterus’ patented High Strain Composite (HSC) Trussed Collapsible Tubular Mast (T-CTM). SSTM is a high-performance truss of tape-springs with structural mass efficiency twice that of trusses of solid rods (e.g. coilable longeron masts) and four times better than traditional non-trussed CTMs. SSTM booms are inherently low cost because they are fabricated using automated and mold-based processes with minimal touch labor,” the proposal said.
“While optimized for sail sails, SSTMs are also performance enhancing and enabling for a broad range of deployable boom applications. These include satellite and lunar surface solar power systems, large science antennas and instrument booms, telescope sunshades, telescope occulter systems, and lunar towers,” the document added.
Project summaries are below.
Testing and Characterization of A Graphene/Polyethylene Nanocomposite for Solar Sail Applications
Subtopic Title: Advanced Solar Sailing Technologies
STTR Phase I Award: up to $150,000
Gossamer Space
Lansdale, Pa.
University of Notre Dame
South Bend, Ind.
Principal Investigator: Dr. Seunghyun Moon
Estimated Technology Readiness Level (TRL):
Begin: 2
End: 4
Length: 12 months
Technical Abstract
Notre Dame University has recently developed graphene/polyethylene film (PE graphene) that has low density and vastly superior strength compared to any previously existing polymer film. We propose to work with Notre Dame University and Utah State University to adapt this film for space applications such as solar sails.
The performance of solar sails is strongly affected by the ratio between the reflecting area of the sail and the mass of the craft. Current generation sails use coated 2.5 micron polyimide films (CP-1) which are extremely delicate to handle and deploy. The PE Graphene nanocomposite has lower density and vastly superior strength compared to CP-1. In terms of specific strength, the new film material outperforms even the best commercial fibers (such as Dyneema) and can offer dramatically improved performance for solar sails. At the same thickness, it offers roughly 70% of the mass of existing solutions and 50x the strength.
Potential NASA Applications
The polyethylene/graphene nanocomposite film we are adapting for use in space could dramatically improve the performance of solar sails, solar cells and deorbiting devices. If made into a cable form, the extremely high specific strength can also improve the performance of tether and centrifugal launch launch applications.
Potential Non-NASA Applications
This PE graphene film could be a key component of commercial solar sails.
Embedded Sail Antenna Technology
Subtopic Title: Advanced Solar Sailing Technologies
STTR Phase I Award: up to $150,000
Nexolve Holding Company, LLC
Huntsville, Ala.
Utah State University
Logan, Utah
Principal Investigator: Brandon Farmer
Estimated Technology Readiness Level (TRL):
Begin: 2
End: 4
Duration: 13 months
Technical Abstract
A new patch antenna array composed of thin-film materials is proposed to create a significant improvement in the specific mass and specific volume of the antenna array. This innovation will enable the combination of the patch antenna array with a solar sail to address the need for a High Gain Antenna (HGA) option for deep space solar sail missions. The primary objective of the proposed research is to refine the design of the patch antenna array with capability to achieve 30 to greater than 50 dBi performance in either the X, K, or Ka frequency band.
A secondary objective of the research is to present how this patch antenna array can be integrated into a solar sail architecture and deployment mechanism. These objectives will be achieved by constructing components of the patch antenna array from thin flexible materials and combining the antenna array with the structure of the solar sail. The patch antenna array deploys with the deployment of the solar sail, and the unique features of the antenna design create the required separation between the patch elements and the ground plane element of the antenna array.
A deployable HGA will enhance the capabilities of smaller spacecraft. The satellite paradigm has shifted considerably from the use of traditional large and expensive satellites to smaller and more cost-effective models. Advancements in technology are leading to small spacecraft like CubeSats developing the capabilities to perform interplanetary and deep space missions.
A significant challenge associated with using smaller spacecraft for these missions is the communication framework required to transmit and receive data across such vast distances The proposed patch antenna array differs from traditional communications solutions in the fact that the aperture size is not restricted by the size of the spacecraft. The deployable thin film HGA approach will allow the antenna to be sized according to mission needs.
Potential NASA Applications
- Solar Cruiser mission
- Europa Clipper mission
- New Moon Explorer mission
- Artemis program
- Solar Polar Imager – SPI solar sail
Potential Non-NASA Applications
Communication Antennas:
- SpaceX – Starlink
- OneWeb – OneWeb Constellation
- Amazon – Project Kuiper Constellation
- Capella Space – Synthetic Apertures
Solar Sail Integrated Antenna Technology
Subtopic Title: Advanced Solar Sailing Technologies
STTR Phase I Award: up to $150,000
Nanohmics, Inc.
Austin, Texas
Texas State University
Ingram School of Engineering
San Marcos, Texas
Principal Investigator: Dr. Andrew Foley
Estimated Technology Readiness Level (TRL):
Begin: 2
End: 5
Duration: 13 months
Technical Abstract
Nanohmics in collaboration with Texas State University intends to develop a miniaturized, flexible, and multiband PAA architecture using miniaturized, ultra-wideband antennas printed on a common solar sail material (i.e. Kapton). This will include scaling an existing antenna design to bands of interest and developing a high-power, fully-printed electronic switching architecture to advance the power handling and high-frequency operation in these printed active PAAs.
Potential NASA Applications
Deployable/stowable, compact, efficient, multiband, beam formed, light-weight, low-cost, high data-rate, and active phased array antennas are one of the enabling technologies that can suit the needs of several NASA platforms and missions. Compatible reference missions include, Mars Cube One (MarCo) and the Near-Earth Asteroid Scout (NEAScout) missions, as well as contribute to the success of human expedition to Mars and beyond.
Potential Non-NASA Applications
By adapting this advanced performance antenna technology to low-cost, conformal substrates, it becomes lower cost and readily adaptable to nearly any footprint. Potential direct and indirect applications include RF identification tags, smart cards, electronic paper, large area flat panel displays, multi-beam and -band 5G antenna, and White Space broadband internet antenna.
UV stable coating for sail-embedded PV power
Subtopic Title: Advanced Solar Sailing Technologies
STTR Phase I Award: up to $150,000
SSS Optical Technologies, LLC
Huntsville, Ala.
Oakwood University
Huntsville, Ala.
Principal Investigator: Dr. Sergey Sarkisov
Estimated Technology Readiness Level (TRL):
Begin: 3
End: 5
Duration: 13 months
Technical Abstract
SSS Optical Technologies, LLC (SSSOT) together with HBCU Research Institution (RI) Oakwood University (OU) and subcontractor Regher Solar, Inc. (RSI) propose to develop the Polymer Anti-damage Nanocomposite Down-converting Armor (PANDA) coating of solar sail-embedded PV cells that, in addition to blocking UV and ionizing radiation and being UV stable, flexible, and light weight, converts UV into visible radiation that matches the responsivity spectrum of the PV cell.
This makes possible to generate extra electricity thus improving the overall PV conversion efficiency by up to 5%. PANDA coating uses a polymer nanocomposite impregnated with UV absorbing luminescent quantum dots (QDs) to shield the coating itself and the coated solar cells from UV radiation and increase PV power conversion efficiency. This is achieved by using spectrum downshifting of solar UV radiation in the QDs to visible radiation.
The innovativeness of the technology has three features:
(1) UV shielding is combined with the use of the UV energy, otherwise wasted, in the production of additional PV electricity;
(2) UV shielding also prevents polymer photodarkening, and
(3) solar spectrum conversion from UV to visible-NIR is highly efficient.
The overall goal is to develop and demonstrate feasibility of a UV stable coating for sail-embedded solar cells that improve PV power output. To reach the goal, the following technical objectives are identified
(1) Design and implement spectrum converting QDs and produce PANDA coatings.
(2) Enable UV stability of PANDA and its perforamnce as a protector of solar cells from UV radiation and enhancer of PV conversion efficiency.
(3) Conduct experiments on both UV stability and conversion efficiency, analyze experimental data and make conclusions on feasibility of the proposed ideas.
Potential NASA Applications
If successful, the proposed technology can be implemented as “UV stable thin-film protective coating for sail-embedded power-generation…”, Scope “Next-Generation Solar Sail System Techn.”, topic T5.05 “Advanced Solar Sailing Technologies”, Focus Area 5 “Communications and Navigation”, NASA FY 2022 STTR Solicitation. PANDA can be used to protect solar power blankets within Scope “Photovoltaic Energy Conversion”, Topic S16.01 “Photovoltaic Power Generation and Conversion”, Focus Area 2 “Power, Energy and Storage”, the same NASA Solicitation.
Potential Non-NASA Applications
One of the major potential non-NASA applications of PANDA technology is the improvement of the efficiency of solar PV panels while protecting them from solar UV and increasing their lifetime.The customers would be national grids and rural communities and the owners of the cameras, such as the government security facilities, municipalities, and private entities concerned with surveillance.
Solar Sail Tubular Mast
Subtopic Title: Advanced Solar Sailing Technologies
STTR Phase I Award: up to $150,000
Opterus Research and Development, Inc.
Loveland, Colo.
Regents of the University of Colorado
Boulder, Colo.
Principal Investigator: Thomas Murphey
Estimated Technology Readiness Level (TRL):
Begin: 3
End: 4
Duration: 13 months
Technical Abstract
Solar Sail Tubular Mast (SSTM) is a lightweight version of Opterus’ patented High Strain Composite (HSC) Trussed Collapsible Tubular Mast (T-CTM). SSTM is a high-performance truss of tape-springs with structural mass efficiency twice that of trusses of solid rods (e.g. coilable longeron masts) and four times better than traditional non-trussed CTMs. SSTM booms are inherently low cost because they are fabricated using automated and mold-based processes with minimal touch labor.
Opterus is currently proving out similar booms (optimized for high load applications) at the 20m (65 ft) length scale using the same materials, tooling, curing, and fabrication equipment that will be used here. Processes are only limited in length by the facility, currently 120m (400 ft). This effort will optimize and develop booms with a linear mass density of less than 50 grams per meter while maintaining the stiffness and strength to support 10,000 m2 and larger high performance sail systems.
SSTM provides a lower cost and lower risk solution by avoiding spin deployment and stabilization complexities. The complexity, challenge, and risk of cable stays (guywires) are similarly not needed with SSTM. Prototype booms will be designed, fabricated, and tested. SSTM is enabling for the next generation of 10,000 m2 large class solar sails for multiple heliophysics missions including HISM (High Inclination Solar Mission), SPI (Solar Polar Imager), and next generation space weather monitoring missions. SSTM can also enable a faster transit to deep space, which is needed for the Interstellar Probe Mission.
Potential NASA Applications
While optimized for sail sails, SSTMs are also performance enhancing and enabling for a broad range of deployable boom applications. These include satellite and lunar surface solar power systems, large science antennas and instrument booms, telescope sunshades, telescope occulter systems, and lunar towers.
Potential Non-NASA Applications
DoD and commercial applications additionally include large communications and sensor platforms. SSTMs are also enabling for large area thermal and RF shield systems.
