SmallSat Thrusters Highlight e-Propulsion Technology at SpaceTech Expo-Europe 

Hall-effect thrusters from ExoTerra are among cutting-edge e-propulsion technologies to be showcased at SpaceTech Expo-Europe in November 

Always a showcase for cutting-edge technology in aerospace progress, SpaceTech Expo-Europe will have an assortment of e-propulsion solutions on display when it opens in Bremen, Germany on November 14. Advancements in propulsion using Hall-effect thrusters for microsatellites, along with space-grade instrumentation, cryogenic, superconductivity and vacuum technology will be among the solutions exhibited. ExoTerra, Enpulsion and Thermocoax are among the companies involved in Hall-effect thrusters. Other exhibitors highlighted in this report are Bartington Instruments, Stirling Cryogenics and Pfeiffer Vacuum. Webcom Communications, the publisher of New Power Technology, is a long-time media partner of the event. 

As the small-satellite market expands, so do the demands for specialized propulsion powered by Hall-effect thrusters. Unlike chemical propulsors traditionally used in spacecraft, Hall-effect systems generate thrust from a magnetic field that accelerates the propellant, usually xenon. They are less powerful than chemical propulsors but require less fuel and propel for longer, making them ideal for long-distance space exploration. 

In June, Littleton, Colorado-based ExoTerra marked a milestone when its Halo propulsion system successfully lit on its first attempt and powered a DARPA (Defense Advanced Research Projects Agency) spacecraft. The Halo module is an integrated electric propulsion system designed and built by ExoTerra in Littleton, Colorado around the company’s Halo Hall-effect electric thruster, propellant distribution components, and power processing unit. The demonstration marks the first operation of a Halo in orbit. Additional modules are expected to be commissioned soon in successive missions. 

Mike VanWoerkom, CEO and founder of ExoTerra 

“Working with BCT and DARPA on the Blackjack program has been a great experience,” said ExoTerra’s CEO Mike VanWoerkom. “We’re all very excited to finally have the thruster validated in space and are looking forward to providing propulsion for several more flights in the coming year.” Founded in 2011, ExoTerra designs, manufactures, and tests electric propulsion elements for small spacecraft, from discrete components to integrated propulsion modules to full spacecraft buses. 

Another small-sat thruster provider on the show floor will be Enpulsion of Austria whose nano-module approach has quickly made it a leading player for powering small satellites, allowing integrators to scale the modules to their specific power needs. Enpulsion nano modules can be clustered to build scaleable, completely self-contained propulsion systems. 
Thermocoax of Suresnes, France located in the outskirts of Paris, will be demonstrating its expertise in designing and fabricating magnetic coils for Hall-effect thrusters. The company has been supplying coils for HET thrusters for more than ten years. The technology behind the Hall-effect thruster means lower fuel consumption which can translate into 30% less fuel weight. Since electrical power is a determining factor for thrust, it provides for a range of engines from 500 watts to more powerful models of 5 kW. 

Thermocoax magnetic coils are primarily intended for manufacturers of new-generation Hall-effect  thrusters that will be used in geostationary satellites where electric propulsors can be deployed in conjunction with chemical propulsors for the different satellite maneuvers in orbit. Its coils are also ideal for application in space probes on very long-distance explorations. 

The magnetic field required for electrical propulsion is generated by placing magnetic coils around the spacecraft engine. The coils are supplied with cables that have a specific geometry and customized connectors to support the constraints associated with the application and usage time. The company’s proprietary mineral insulated cabling is coiled on specific nodes and affixed by a special soldering procedure. 

Bartington Instruments recently developed a replacement magnetometer for the Gripen-C multi-role combat aircraft manufactured by Saab.  

Serving a variety of applications, Bartington Instruments of the UK designs and manufactures high precision fluxgate magnetometers, gradiometers, magnetic susceptibility instruments, Helmholtz Coil systems and associated data acquisition equipment for the aerospace industry. 

Based in the UK and founded in 1985, today around 80% of its products are exported worldwide to customers in varied market sectors including aerospace, land/sea/air defense, surveillance, security, space, physics, geophysics, industry, archaeology, medicine, and oil and mineral exploration. It recently completed development of a replacement magnetometer for a Saab combat aircraft, the first product it has designed specifically for use in aircraft navigation systems. 

Numerous applications in aerospace require cryogenic cooling and Stirling Cryogenics, located in Eindhoven, The Netherlands, specializes in supplying solutions for them, often highly customized. Objects in space are exposed to its almost perfect vacuum, cold and solar radiation. Organizations such as NASA, ESA, universities and commercial organizations involved in building spacecraft, satellites, components and instruments often need to test their equipment and materials in extreme low and high temperatures and vacuum conditions. This is done in earth-based simulation chambers in which the conditions in space are simulated by creating a high vacuum and extreme low temperatures. 

Stirling Cryogenerators, based on the reversed-Stirling cycle, are the heart and key component in all that Stirling does. 

Liquid oxygen is widely used as oxidizer in different types of rockets. By cooling the liquid oxygen below its usual boiling temperature, density of the liquid increases so more mass can be stored in the same volume. Cooling of a cryogenic liquid flow can be done directly in the heat exchanger of a Stirling Cryogenerator.  

With the growing interest in de-carbonizing air traffic, liquid hydrogen is seen as the fuel of the future since it can be produced in a fossil-free way and has a high energy to mass ratio. Projects in development typically require relatively small amounts of liquid hydrogen, leading Stirling to provide small production systems that can be used onsite. 

Cooling of superconducting magnets is another key application for the company. In tandem with liquid hydrogen as airplane fuel, superconductivity is regarded as the one of the main technologies to provide thrust using superconductive motors and other components. Newly built superconducting magnets need to be cooled down from ambient for the first time, and to be kept cold while in use. 

Pfeiffer vacuum chamber 

Another exhibitor steeped in solutions for space technology is Pfeiffer Vacuum which produces an extensive range of specialized pumps, leak detectors, measurement equipment, as well as vacuum systems and chambers for space simulation applications. A number of its products are also applied to hydrogen and fuel cell applications. 

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