Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 1.50M | Year: 2015
ABSTRACT:The Hall thruster propulsion system consists of the thruster, cathode, propellant management system and the power processing electronics. The power processing unit (PPU) represents largest fraction of the system dry mass. In addition, the delivery time and cost of radiation hard electronics and issues regarding long-term pre-launch fuel storage make it difficult for electric propulsion systems to meet the operational needs of responsive space missions. In response to the Air Force need for satellites that are both operationally responsive to a launch command and operationally responsive to the warfighter on-orbit, Busek is purposing a paradigm shift from the traditional architecture of electric propulsion systems. The proposed system leverages our flight qualified low power Hall thruster technology. We propose to power the propulsion system using a single multifunctional power converter that has the potential to significantly reduce the PPU cost, mass, volume. We will also investigate the technical feasibility of a non-toxic iodine fueled thruster as a means of reducing the stored propellant tankage mass and volume. Iodine would be stored as a solid allowing pre-fueled long term storage of the propulsion system until a responsive space need arises. In Phase I we will conduct a comprehensive system design and mass optimization study supported by an experimental demonstration using a single multifunctional power converter to power the cathode and thruster. In Phase II we will design and build engineering prototypes of each subsystem and conduct a TRL 6 integrated system demonstration. At the conclusion of the program the integrated system will be delivered to AFRL for extended duration testing in facilities.BENEFIT:The AFRL IHPRPT Program is investing in the development of long life low power HET systems. A key technology identified in the Beyond IHPRPT study is an extremely long life, low mass variant of the BHT-200 and BHT-600 HET systems. The multi-functional converter concept is attractive for its reduction in overall propulsion system mass complexity and cost. Hall thrusters have also been identified as a key technology for NASAs vision of space exploration. NASA missions beyond Earth orbit can be enabled by the wide throttle range and broad Isp-thrust operation of Hall thrusters. A study conducted by the SMD ISPT Project in 2004 confirmed the significant potential of EP for space science missions, including orbiters about Pluto, Neptune, and Uranus; rendezvous/return with Kuiper Belt Objects and primitive bodies in the outer Solar System; and extensive surveys of major asteroid groups. Commercial satellite manufacturers; SS/L, Boeing, Lockheed Martin and Orbital Sciences have all shown a strong interest in low power HET systems for primary propulsion on LEO spacecraft and station keeping on GEOSats.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 750.00K | Year: 2015
ABSTRACT: Busek Co. Inc. proposes to develop a high power, low-mass Hall effect thruster. The baseline thruster is sized at nominally 8kW power level. A specific feature to be implemented includes the use of SmCo permanent magnets. The goal of the effort is to reduce thruster specific mass to 60%. In Phase I Busek evaluated an existing permanent magnet thruster to develop the theoretical and experimental underpinnings of the full power design. Following the experimental effort Busek prepared the detailed engineering design of the thruster designated BHT-8000-PM. The thruster design was supported by magnetic modeling, lifetime predications, and thermal and structural analysis. In Phase II Busek will perform functional, performance and plume testing of the prototype thruster. Using the lessons learned from the prototype thruster development, Busek will design, build and environmentally and performance test an advanced version of the thruster with a center-mounted cathode to raise the maturity level to TRL 6. BENEFIT: The DoD has recently begun an effort to understand the potential of high-power EP for national assets such as AEHF, GPS, WGS, SBIRS, and reconnaissance satellites. Equipping assets with full EP for both orbit transfer and station keeping would allow dual-manifest launches and LEO injections in the majority of cases, saving hundreds of millions of dollars across constellations. In the case of the Space Missile Command (SMC) fleet, EP would allow dual-manifest LEO launches to occur, saving ~15% of the fleet-wide budget which includes the procurement, launch, and operation. The commercial industry is already transitioning to all-electric satellites to perform both orbit raising and station keeping. These include domestic satellite manufacturers Boeing (presently operating L-3 ion engines), Lockheed-Martin, Orbital Sciences and Space Systems/Loral, Between 2020 and 2022, 45 satellite orders are expected to launch having payload power at or near 14 kW, with 18 of these at or above 14 kW. This trend of higher power coincides with advancements in solar array technologies. Present state of the art arrays average 40 W/kg, whereas next generation arrays performance >10 W/kg.
Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 746.92K | Year: 2015
ABSTRACT: Busek Co. Inc. proposed to explore the feasibility of a highly scalable miniature ion beam generator system capable of producing atomic and/or molecular beams with velocities corresponding to energies of 50-100 keV and suitable for Space applications. The proposed system combines the technologies of ion beam generation from an electrospray ion source utilizing ionic liquids and efficient high electric field generation by compact pyro-electric crystals. In Phase I, Busek demonstrated the feasibility by designing and testing key components of a novel single emitter electrospray ion source powered by pyroelectric crystals. We modelled the ion source with emphases upon effects of crystal temperatures on the electric field created and field enhancement experienced by the ionic liquids. We validated the hypothesis by observing experimentally the generation of ion currents of positive and negative polarities. The Phase II effort shall fabricate a prototype ion source based on the Phase I findings and demonstrate its operation. BENEFIT: The proposed novel ion source combines the benefits of the efficiency and compactness of electrospray ionic-liquid ion emission source, with a low power and compact electric field generation source provided by pyroelectric materials. Such a device is applicable to a variety of applications ranging from energetic ion beams for materials processing, to small high specific impulse electric propulsion devices and potentially application in remote sensing.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 749.90K | Year: 2016
Busek is developing an advanced iodine feed system for Hall Effect Thrusters (HETs), ion engines, cathodes, and other plasma generators. The feed system features an innovative piezo driven valve that saves volume, mass, cost, and energy with respect to state of the art alternatives. The feed system also features a low mass plastic propellant tank that may be manufactured through additive processes. This allows low cost, complex shapes that can maximize the use of available space inside volume-restricted spacecraft. The feed system will be especially attractive for small spacecraft and CubeSats. Iodine stores as a solid and sublimates at modest temperatures as the molecule I2, which allows many benefits with respect to traditional Hall effect thruster fuels such as xenon and krypton. These advantages include higher storage density, lower storage pressure, the ability to test high power systems at space-relevant conditions in modest facilities, the capability to store propellant in space without active regulation, and the capacity to transfer propellant at low-pressure conditions in space. In a space-limited spacecraft, using iodine instead of state of the art xenon could increase available delta-V by a factor of three (3) or more. In Phase I, Busek developed a feed system featuring the advanced components, which was integrated into the iSAT spacecraft form factor. The system was then tested with an iodine compatible Hall effect thruster in relevant space conditions. In Phase II, an improved feed system will be designed, built and tested. Major Phase II technical objectives include developing an engineering model iodine resistant, piezo driven flow control valve, finalizing the feed system control architecture, identifying and evaluate commercial components to fill out the system, and building and characterizing the system. At the conclusion of the Phase II effort, engineering model valves will be delivered to NASA for further characterization.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 1.62M | Year: 2014
In Phase I Busek matured the design of an existing 15-kW laboratory thruster. Magnetic modeling was performed to generate a circuit incorporating magnetic shielding. Erosion modeling predicts extremely long lifetime and high throughput. A detailed mechanical design of the thruster resulted in an overall assembly with specific mass
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.89K | Year: 2016
Busek proposes to develop a compact electrospray propulsion system with unprecedented capability. The 1500s Isp while requiring less than 45W of power. Compared with existing state-of-the-art CubeSat thrusters, the system will provide more thrust than available gridded ion engines at lower power and without greatly penalizing Isp. Busek will develop the thruster through new innovations merged with existing, flight-qualified electrospray thruster heritage. The extremely low flow rates of high Isp electrospray thrusters permits passive feeding, where pressure vessels, regulators and their associated electronics are eliminated in favor of a natural flow regulation; freeing up valuable volume budget for additional propellant or payload. However, passive electrospray thrusters in general suffer from flow control ambiguities, leading to irrecoverable failures due to the conductive propellant degrading or shorting electrical isolators. Busek will integrate new innovations that overcome these issues into a systematic development methodology, leading to the most robust passively-fed electrospray thruster to date. The system will be capable of more 0.7kg of propellant throughput (~1000m/s deltaV for a 6U CubeSat) and be fully scalable to higher capacity.In Phase I Busek will develop a thruster head that provides >300microN of thrust and includes a never-saturated porous reservoir. The restorative capillary force of this reservoir will prevent liquid seepage and maintain consistent performance. An annular geometry will circumvent propellant and surface degradation due to edge effects. In parallel, a method for transferring IL from high open volume storage tanks to the intermediate porous reservoir will be demonstrated. Finally, the complete 1.2mN thruster, comprising an array of 4 thruster heads will be designed. Phase II, will validate this system and culminate with delivering an engineering model
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 749.98K | Year: 2016
Busek Co. Inc. proposes to advance the maturity of an innovative Spacecraft on Umbilical Line (SOUL) System suitable for a wide variety of applications of interest to NASA, DoD and commercial missions. SOUL is a small (
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase II | Award Amount: 1.50M | Year: 2015
Busek, in partnership with Morehead State University (MSU), proposes to develop a versatile 6U CubeSat capable of reaching a lunar orbit from GEO. The primary objective of the Phase II effort is to demonstrate a complete, mini ion propulsion system that provides ~3000sec Isp heretofore unavailable to CubeSats, with a solid-storable iodine propellant. This type of propulsion technology would be a huge mission enabler and ideal for volume-limited satellites such as CubeSats. The 6U bus, combined with ion propulsion, has already shown being highly attractive to science payload developers targeting the upcoming SLS/EM-1 lunar mission. During Phase I Busek successfully demonstrated the world's first iodine-fueled gridded ion thruster "BIT-3". Key performance characteristics of BIT-3 include a compact design envelope (2.8km/s delta-V to a 6U/12kg CubeSat. The ultimate goal of the LunarCube program is to undertake a mission to the Moon from GEO or a translunar trajectory (such as the EM-1 drop-off) that would demonstrate the propulsion system, and carry out a lunar science program as a capability demonstration of the platform. During this mission, a related goal is to demonstrate that much of the spacecraft's miniature electronics, primarily C&DH, communications, and the propulsion system's PPU can be based on low cost components and survive the harsh deep-space environment.
Agency: National Aeronautics and Space Administration | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 124.99K | Year: 2016
The conversion of heat to power has proven to be vital in flight missions where solar power generation is not an option. Radioisotope thermoelectric generators that converted heat produced by a decaying nuclear source to power have been used on missions such as Cassini, New Horizons, Galileo, Ulysses and the Mars Science Laboratory. Although never flown by the United States, thermionic converters have also been investigated for space applications. Their improved efficiency over thermoelectric generators makes them an attractive option, but the high operating temperatures required have thus far been a significant obstacle to their use. Thermionic generators convert heat energy directly into electrical power. An emitter electrode on a heat source emits electrons across a vacuum gap to a cold electrode. The generated current is pumped through a load where it can do useful work before it is returned to the emitter. Thermionic generators do not use any moving parts or working fluid, which results in highly reliable devices that do not need frequent maintenance. Unlike thermoelectric generators, which have exhibited efficiencies only up to about 8%, state-of-the-art thermionic generators operate with efficiencies approaching 20%. This proposal seeks to study the use of the nanomaterial C12A7 electride as an electrode material. C12A7 electride has been shown to emit stably at temperatures in excess of 1600 degrees C and has a measured work function between 0.8-2.1 eV. Due to its low work function, C12A7 electride has the potential to greatly improve the efficiency of the state-of-the-art in thermionic energy conversion as well as enable device operation at much lower temperatures than is currently possible. Busek previously has investigated C12A7 electride in thermionic emission configurations for space propulsion hollow cathode applications. In the proposed work, Busek will evaluate the potential benefits of a C12A7 electride thermionic converter electrode.
Agency: National Aeronautics and Space Administration | Branch: | Program: STTR | Phase: Phase I | Award Amount: 124.99K | Year: 2016
Busek, in partnership with Arizona State University (ASU), proposes to develop a robotic resource prospecting mission to a near-Earth asteroid using a 6U CubeSat, nicknamed "AstroCube". This ambitious mission is enabled by Busek's iodine-fueled BIT-3 RF ion propulsion system that can deliver ~1mN of thrust and ~2200sec of total Isp with 65W nominal input power. With 1.6kg of solid iodine propellant onboard, the BIT-3 thruster will provide AstroCube approximately 3.1km/s of delta-V maneuverability to rendezvous with the target, Asteroid 2001 GP2, during its next closest Earth approach in October 2020. The 6U CubeSat platform is chosen due to its low cost and ease of access to ride-share opportunity on GEO-bound upper stages, as well as on the upcoming NASA SLS demonstration missions. The AstroCube mission will leverage a unique deep-space 6U CubeSat bus with ion propulsion, currently being co-developed by Busek and Morehead State University (MSU) under NASA's Lunar IceCube flight program. The proposed mission will encompass several technology innovations, including compact science instruments and autonomous CONOPS, which are the focus of this Phase I development. A rad-tolerant, 1/4U sized camera-Lidar device will give AstroCube "eyes" to survey the asteroid and help with proximity navigation. Due to the asteroid?s weak gravitational field, the spacecraft will be required to use real-time depth image processing and its ion thruster to navigate around the asteroid during final approach to a low stationary altitude. Once such close proximity is reached, a 1U sized neutron spectrometer will be activated to characterize the abundance of hydrogen, which would indicate presence of water ice, by detecting slow-moving neutrons as they scatter off the asteroid's regolith from the bombardment of cosmic rays.