KEYWORDS: Data Fusion, Event Detection, Typing/Discrimination. Tactical Parameter Estimation, Multi-source fusion, SBIRS, OPIR
AF171-070
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TITLE: Advanced Solar Cell Metallization
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TECHNOLOGY AREA(S): Space Platforms
OBJECTIVE: Develop innovative concepts for producing solar cell metallization which will provide performance resilience to the presence of semiconductor cracks.
DESCRIPTION: Presently, crystalline solar cells (e.g. silicon, gallium arsenide, etc.) can degrade from cleaving or fracturing along crystallographic planes under mechanical stress. This degradation mechanism is being exacerbated due to the trend for the use ever thinner solar cell structures as a means of saving mass, reducing materials costs and improving device performance. Generally speaking, solar cells with cracks or cleaves do not suffer performance degradation unless the fracture extends through the metallization on the front and/or rear surface of the device [4]. Should the metallization also fracture, as is extremely common, the solar cell performance can suffer due to increased series resistance or even loss of active solar cell area.
Recent research has demonstrated that metal matrix composite (MMC) solar cell metallization has the potential to provide electrical connectivity across large (> 30 micron) fractures [1-3]. These MMC materials, consisting of multi-wall carbon nanotubes in silver, have demonstrated the ability to “self-heal” should they be strained to electrical failure. A wide variety of approaches for depositing MMC metallization have been explored, including electroplating, spray coating, film transfer and screen printing.
The goal of this research effort is the development of an advanced solar cell metallization that has the ability to maintain solar cell performance in the presence of cleaves or fractures in the semiconductor material. The material may accomplish this function by being immune to fracture or by providing good electrical conductivity across fractures. A successful technology should demonstrate a < 5% performance degradation in the solar cell should a fracture occur. The materials and deposition processes should be suitable for high-volume, low-cost deposition as there is potential application of this technology for both space and terrestrial solar cell technologies.
The solar cell metallization technology should be capable of supporting a 15-year mission in GEO or Medium Earth Orbit (MEO) and 5 years in Low Earth Orbit (LEO) after ground storage of 5 years.
PHASE I: Perform preliminary analysis and conduct trade studies to validate concepts for the advanced metallization. Perform preliminary risk mitigation experiments to validate metallization components and deposition approaches. Demonstrate preliminary crack-tolerance behavior.
PHASE II: Fabricate and deliver engineering demonstration units consisting of advanced metallization integrated with operational solar cells (e.g. space triple junction solar cells, terrestrial silicon solar cells, etc). Demonstrate ability of metallization technology to provide fracture/crack tolerance for device performance and ability to be integrated into appropriate higher order assemblies (e.g. panels, modules) with high reliability interconnects, etc.
PHASE III DUAL USE APPLICATIONS: Transition the solar cell metallization technology developed for use on DoD, NASA or Commercial spacecraft.
REFERENCES:
1. Silver–Carbon-Nanotube Metal Matrix Composites for Metal Contacts on Space Photovoltaic Cells, Omar K. Abudayyeh; Nathan D. Gapp; Cayla Nelson; David M. Wilt; Sang M. Han, IEEE Journal of Photovoltaics, Year: 2016, Volume: 6, Issue: 1 Pages: 337 – 342.
2. Carbon nanotube metal matrix composites for solar cell electrodes, Nathanael D. Cox; Jamie E. Rossi; Brian J. Landi, Photovoltaic Specialist Conference (PVSC), 2015 IEEE 42nd, Year: 2015.
3. Carbon nanotube reinforced cu metal matrix composites for current collection from space photovoltaics, Adam B. Phillips; Brandon L. Tompkins; Zhaoning Song; Rajendra R. Khanal; Geethika K. Liyanage; Nathan D. Gapp; David M. Wilt; Michael J. Heben, Phot
4. Quantitative local current-voltage analysis with different spatially-resolved camera based techniques of silicon solar cells with cracks, Tobias M. Pletzer; Justus I. van Mölken; Sven Rißland; Brett Hallam; Emanuele Cornagliotti; Joachim John; Otwin Br
KEYWORDS: Solar Cell, Metallization, Resilience, Crack-tolerant
AF171-071
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TITLE: Integration of Tactical and Individual Satellite Operations with Global Operation and Control
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TECHNOLOGY AREA(S): Space Platforms
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.
OBJECTIVE: Develop, integrate, and demonstrate a toolset which would enable seamless integrate of individual and tactical satellite operations centers with a higher level operations center Space Operations Center such as the JSpOC.
DESCRIPTION: The Joint Space Operations Center (JSpOC) has the function of maintaining near real-time situational awareness of all space assets. Unfortunately, today’s Air Force satellites are largely operated from a heterogeneous set of operations centers on isolated networks. Satellite data, both relating to system state of health and that relating to payload ("mission products"), flows from these centers in general using laborious manual processes with limited automation. This construct results in delays in reporting, delays in responding to anomalous conditions, and hinders the ability to obtain real time situational awareness for our space assets.
As a method to integrate these individual operations centers, the Air Force is exploring strategies that greatly enhance automation, such as the use of approaches like GMSEC (Reference 1) as an infrastructure for the management of satellite operations data. If successful, this will enable standardization of satellite operations for ground assets through service-oriented architectures. Approaches such as GMSEC have been shown to dramatically reduce complexity, by providing unified mechanisms to expose and manage both control and data products associated with these systems. This can lead to a significant reduction of the operational footprint (through improved prospects for automation), as well as increased timeliness in the gathering and analysis of data. The unification promotes development of tools and decision aids, contributing to a more uniform situational awareness of systems associated with this improved infrastructure.
Meanwhile, the JSpOC Mission System (JMS) has been developing a net-centric infrastructure to promote/enable real-time space system awareness using a large number of net-centric command and control and space situational awareness tools. The problem is that to date JMS and GMSEC have been developed independently, with little thought as to their effective integration. Integration of the two systems would allow the real-time flow of satellite events to the JSpOC.
Additionally, we would like to further expanding the utility of these approaches. For example, for Operationally Responsive Space (ORS), warfighters expect to ability to directly task space assets in near real time disseminating of mission products from the assets to the theater. While the theoretic possibility of such concepts has been shown in limited demonstrations, the ability to task assets should have the capability to access all necessary
information while eliminating inefficiencies that would not scale especially if the demonstrated warfighter tasking systems were to be used operationally.
JMS data services can be developed which would enable utilizing near real-time awareness of areas such as terrestrial and space weather, orbital position, and target information. Use of this information in a warfighter tasking system would enable optimization of satellite tasking and avoid loss of data.
The objective of this topic is to develop an effective bridge between GMSEC and JMS and to demonstrate this capability via a set of operational use cases. One approach, for example, might involve a set of modules to allow the seamless transfer of data between GMSEC and JMS. It is envisioned that success proposers will work closely with the Air Force in order to leverage existing technologies and to ensure technical efforts are consistent with overall responsive satellite development goals. Proposed concepts should strive for designs that can eventually lead to development of a complete comprehensive system, i.e., scalable to operational settings.
PHASE I: Design, develop, and demonstrate a robust set of software modules that would enable seamless transfer of satellite system information between JMS and GMSEC. A proof of concept demonstration with a representative set of use cases is highly desirable. Utilize test results to identify key technical challenges, develop a mitigation strategy, and to develop the Phase II program plan.
PHASE II: Utilizing the results of phase 1, develop and demonstrate a more robust system using an approved set of space system scenarios in a relevant environment. The demonstration should achieve the functional and interface specifications of the SMC/AD Enterprise Ground Systems (EGS).
PHASE III DUAL USE APPLICATIONS: The proposed effort would develop satellite system technologies that are applicable to both commercial and military satellites. In particular the technologies would have applicability to NASA which also operates a large number of space assets.
REFERENCES:
1. GMSEC home page, NASA/GSFC,http://gmsec.gsfc.nasa.gov/.
2. Rico Espindola and Gayla Walden, Aerospace Corp, “Developing a Responsive Ground System Enterprise”, Aerospace Corp Magazine Summer 2009 Edition.
3. DISA Net Centric Enterprise Services,http://www.disa.mil/nces/.
KEYWORDS: GMSEC, JSpoC Mission Systems, JMS, Net Centric Space systems, Satellite Operations, Satellite Tactical operations, responsive space
AF171-072
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TITLE: Integrated Photon Management for Multijunction Solar Cells
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TECHNOLOGY AREA(S): Space Platforms
OBJECTIVE: Technologies are sought to improve the radiation hardness of multijunction solar cells while improving their conversion efficiency through the use of integrated photon management features.
DESCRIPTION: III-V multijunction solar cells are the highest efficiency and most widely used solar cell technology currently used on spacecraft. Many aspects go into the design of space solar cells, including means for mitigating degradation due to high energy proton and electron radiation. Current generation space solar cells are comprised of a GaInP top subcell, a GaAs middle subcell, and a Ge bottom subcell. In this material configuration, the GaAs middle subcell is generally the most susceptible to damage from radiation. At end-of-life, the solar cell is usually limited in current by this GaAs subcell. In addition, as trends continue towards higher number of subcells (4+) in a space solar cell, the vulnerability to radiation degradation increases.
This solicitation is looking for methods by which the radiation hardness and performance of a multijunction solar cell can be improved using integrated photon management techniques such that full optical absorption may be accomplished with a significantly thinner absorber region. The direct result should be an increase in remaining factor (final power / initial power), relative to current state-of-the-art. These techniques may include photon scattering/trapping or plasmonic structures that are built into the device structure itself. Due to the light scattering or coupling, the thickness of a given subcell could be decreased without adversely impacting the current through the cell. In turn, the degradation to minority carrier diffusion lengths due to radiation damage will have a lesser impact on end-of-life performance. Additionally, the reduced thickness provides a potential benefit to the subcell voltage due to a lower saturation current.
Initial development of integrated photon management structures should target the weakest subcell within a multijunction solar cell. For the current generation cell mentioned above, this would mean targeting the GaAs subcell. However, other multijunction solar cells, such as the inverted metamorphic multijunction (IMM), upright metamorphic multijunction (UMM), or other high-efficiency cells may be used as a baseline. The proposed designs for integrated photon management features should be tested within a multijunction structure. This solicitation is not interested in enhancements for single junction structures. The technologies proposed should be capable of successfully being qualified via standards such as AIAA S-111 for solar cells.
The solar cell technology should be capable of supporting a 15-year mission in GEO or Medium Earth Orbit (MEO) and 5 years in Low Earth Orbit (LEO) after ground storage of 5 years.
PHASE I: Phase I should examine test cases by which full optical absorption in a sub-cell of a multijunction stack can be realized in significantly thinner absorber layers using integrated photon management features. Analysis of the proposed methods should be performed and initial proof-of-concept testing should be demonstrated, with a potential down select.
PHASE II: Phase II builds upon the analysis and testing performed in Phase I to further refine the technologies of interest. Identified technologies should be evaluated for their radiation hardness and overall cell performance metrics. Demonstration of the technology should be performed, including electron radiation testing.
PHASE III DUAL USE APPLICATIONS: Phase III further matures the technology developed in Phase II and should result in a solar technology which is ready to enter qualification testing (e.g., AIAA S-111).
REFERENCES:
1. H. A. Atwater and A. Polman, Nat. Mater.,vol. 9, pp. 205-213, 2010.
2. V. K. Narasimhan and Y. Cui, Nanophotonics, vol. 2, no. 3, pp. 187-210, 2013.
3. R. B. Wehrspohn and J. Upping, J. Opt., vol. 14, no. 2, pp. 024003, 2012.
KEYWORDS: spacecraft, multijunction solar cell, photon management, radiation hardness
AF171-073
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TITLE: Weather Satellite
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TECHNOLOGY AREA(S): Space Platforms
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.
OBJECTIVE: Develop a mission concept and low earth orbit small satellite bus and/or small sensor payload suitable for timely global multispectral imaging of cloud cover for military operations. Consider other data sources for a heterogeneous architecture.
DESCRIPTION: The Department of Defense (DOD) uses data from military, U.S. civil government, and international partner satellite sensors to provide critical weather information and forecasts for military operations. The DOD’s primary existing weather satellite system is the Defense Meteorological Satellite Program (DMSP), which will soon be removed from operational service. The United States Strategic Command (USSTRATCOM) has identified potential future needs in the current weather infrastructure to support tactical operations: Cloud Characterization and Theater Weather Imagery. Timely multispectral satellite imagery addresses both needs. Required resolution is 1 km in visible and 2 km in IR. Required timeliness is revisits in 4 hours or less. Data formats are to be compatible with existing weather processing centers. Post processing should be rapid enough to ensure tactical availability of data within 10 minutes of ground readout. There may be flexibility in these spectral bands and other requirements by clarifying with tactical operators what specific mission utility is required.
System trades will be performed to evaluate alternative mission concepts that could include newly deployed satellite(s) to LEO or GEO, hosted payloads, existing military or commercial satellite systems, or alternative data sources. Ground or airborne sensors may be considered but must be part of a solution for tactical operations in hostile denied areas. The most cost effective solution that meets the required performance described above will be selected as the baseline approach.
In addition to evaluating alternative mission concepts, a low-cost LEO satellite design will also be developed to a preliminary design review (PDR) level for the Phase I. This LEO satellite design could be one of several identical satellites in a dedicated LEO constellation or one element of a heterogeneous architecture leveraging data from other satellites or sources.
The Phase II will mature the LEO small satellite mission concept for timely global multispectral imaging of cloud cover, according to the requirements outlined above. The space segment design will include the satellite bus and payload, and interfaces / requirements for launch and operations, including ground communications links. The Phase II will further develop and deliver a space qualifiable LEO small satellite bus and/or sensor payload to perform multispectral imaging of cloud cover. The satellite bus should utilize standard or prescribed interfaces to proposed launch vehicles and ground segment. Commonly available industry standard data and mechanical interfaces should be used between the payload and bus, if opting to deliver only one or the other, e.g., standard fastener sizes, RS-422, Ethernet, etc. Details of these interfaces may be modified during the course of the effort to accommodate other awardees.
PHASE I: Develop a low-cost mission concept to provide cloud cover and characterization data and design a LEO satellite.
1. Conduct trades to identify mission concept(s) to provide timely global multispectral imaging of cloud cover at minimal system cost.
2. PDR Design of LEO satellite to provide 1 km resolution, multi-spectral imagery of cloud cover, including sensor, orbital configuration, and downlinks.
PHASE II: Based on the Phase I effort, develop and deliver a space qualifiable LEO small satellite bus and/or sensor payload to provide cloud cover and characterization data.
1. Utilize standard interfaces to proposed launch vehicles and ground segment.
2. Utilize standard data and mechanical interfaces between payload and bus, if opting to deliver one or the other, e.g., standard fastener sizes, RS-422, Ethernet, etc. Interfaces may be modified during this effort for concurrent developments.
PHASE III DUAL USE APPLICATIONS: The contractor will pursue commercialization of the various technologies developed in Phase II for transitioning expanded mission capability to a broad range of potential government and civilian users and alternate mission applications.
REFERENCES:
1. USA. DoD. GAO. Analysis of Alternatives Is Useful for Certain Capabilities, but Ineffective Coordination Limited Assessment of Two Critical Capabilities. N.p., 10 Mar. 2016. Web. GAO-16-252R
2. Price, Julie. 2015 JPSS Science Seminar Annual Digest. Rep. N.p.: NOAA.gov. Web.
KEYWORDS: Small satellite, cloud imaging, cloud characterization, global coverage, multi-spectral sensor, visible imagery, infrared, IR, near-IR, SWIR, MWIR, LWIR
AF171-074
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TITLE: Agile Inspector Satellite
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TECHNOLOGY AREA(S): Space Platforms
The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 5.4.c.(8) of the solicitation and within the AF Component-specific instructions. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws. Please direct questions to the AF SBIR/STTR Contracting Officer, Ms. Gail Nyikon, gail.nyikon@us.af.mil.
OBJECTIVE: Produce a small space situational awareness (SSA) satellite system with radically high DeltaV. Satellite should exceed 6 km/s of DeltaV to allow significant orbital maneuverability, for example transfer from Low Earth Orbit to Geostationary Orbit.
DESCRIPTION: Spacecraft characterization is a vital component of Space Situational Awareness (SSA) and the U.S. Air Force’s core mission. A desired capability for SSA is the ability to gather resolved images of objects in Geostationary Orbit (GEO). A number of concepts have been proposed for small satellites with imaging sensors that operate in or near GEO that provide adequate imaging resolution by being close to the resident space objects. An enabling capability for such concepts is a high degree of maneuverability in GEO to allow the small satellite to move between the various GEO objects of interest relatively quickly, and/or to transfer quickly between orbits including from Low Earth Orbit (LEO) to GEO.
The cost of achieving spacecraft maneuverability has traditionally restricted satellite CONOPS and mission areas. These limitations originate from insufficient exhaust velocity with chemical thrusters and the relatively high size, weight, and power (SWAP) of satellite systems. The development of highly efficient electric propulsion systems and the corresponding reduction in satellite SWAP, has made achieving extremely high amounts of DeltaV feasible.
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