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(27 November 2020 – ESA) High-power supercapacitors – already found within terrestrial electric cars, trains, lifts and cranes – are on their way to space.

An ESA-led project with Airbus Defence and Space developed and tested a supercapacitor design able to provide brief bursts of very high power levels to space missions as required. Potential uses might include operation of high-power satellite radar systems, to stabilise overall onboard power during solar eclipses or other such events or launcher thrust vectoring.

Bank of supercapacitors engineering model (courtesy: ESA/Airbus Defence and Space)

“While traditional batteries store electric energy on a chemistry basis, supercapacitors do so on the basis of physics. The energy is stored as electrostatic charge, within an electrochemical double layer at the boundary between an organic electrolyte and activated carbon layers,” explains energy storage engineer Brandon of ESA’s Energy Storage section.

“This means they can both store and discharge power at a very fast rate that batteries cannot match, for many thousands of cycles with almost no internal resistance. However they have the corresponding disadvantage that they possess a lower overall energy density, so are able to store only a fraction the amount of energy of a battery with the same mass.”

Supercapacitors are, for instance, often used within electric and hybrid cars, storing the electric energy generated by braking wheels for later reuse and supplying power boosts for rapid acceleration.

“We performed an initial study of such a ‘Bank of Supercapacitors’ unit through ESA’s Advanced Research in Telecommunications Systems, ARTES, programme,” adds Brandon. “We studied possible applications and which commercial cells could be feasible for the application in space. The results of this study were very promising.

“Then Airbus Defence and Space in France approached us, wanting to finalise and qualify such a design for space. This project proceeded on a co-funded basis through our General Support Technology Programme – preparing promising products for space and the marketplace.”

The first challenge was to design and construct a working prototype ‘Bank of Supercapacitors’ (BOSC), based on 34 supercapacitors in series with three strings in parallel, incorporating thermal sensors to keep it from overheating and degrading.

“To make these prototype BOSCs suitable for space required careful ‘potting’ – meaning the insertion of epoxy between the stacked supercapacitors, connectors and printed circuit boards,” adds Brandon.

“This sealant potting is needed for multiple reasons, firstly to help safeguard these delicate devices from the violent vibration of launch. It also prevents the unwanted interaction of bare wires and to minimise ‘outgassing’ of electrolyte from the supercapacitor can – the release of unwanted gases in the vacuum of space.”

BD Sensors in the Czech Republic– in charge of designing and manufacturing the BOSC – was responsible for developing this critical process.

Mechanical testing – coming down to violent, launcher-strength shaking, as well as exposure to space-quality vacuum and temperature extremes – took place at project partner EGGO Space in the Czech Republic. Radiation testing was also essential, involving kilorads of exposure, to check the bank would go on operating when exposed to the same kind of charged particles experienced in orbit.

Gabriel Beulaguet of Airbus Defence and Space, engineering and project manager for the project, comments: “we have set-up in our laboratory a long life test under relevant electrical, thermal and vacuum conditions. After more than 2.3 million cycles, the performances – especially in terms of fading and balancing – are behaving as expected and the test will continue to run”.

Testing the electrical performance of the BOSC involved millions of charge and discharge cycles, including a dedicated lifetime test campaign to look at ageing effects. In parallel, the BOSC was also subjected to ‘abuse’ testing – involving short circuits, overcharges and physical shock from impacts.

“We found the bank can take a huge amount of current, up to 400 amps, several times without damage,” adds Brandon.

Denis Lacombe of ESA’s Technical Reliability and Quality Division, technical officer for the project, explains: “Now that lifetime testing is about to conclude, after three years of hard work we have a space-qualified product, ready for use by Airbus and added to the European Preferred Parts List so other missions can make use of it as well, enabling high-power space applications of all kinds.”

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Satnav antenna built for ends of the Earth

Satnav antenna built for ends of the Earth

(27 Janaury 2021 – ESA) A new ESA-supported wide-bandwidth satnav antenna has been designed to receive both satellite and augmentation signals from anywhere in the sky, even down to just a couple of degrees above the horizon.

With a growing number of satnav constellations in operation, Canada-based Tallysman Wireless’s new VeroStar antenna aims to pick up all available signals, as well as support the availability of L-band correction service signals. Its development was supported through ESA’s Navigation Innovation and Support Program (NAVISP) programme.

The precision of GNSS fixes is routinely sharpened with correction signals from augmentation systems, such as Europe’s EGNOS and the US WAAS, which also provide ongoing integrity (or reliability) information for high-accuracy and safety-of-life uses, such as aircraft descents. However, these augmentation signals are transmitted by geostationary satellites, hanging at fixed points above the equator, meaning that they become less visible for receivers in the far north or south.

VeroStar wide-bandwidth satnav antenna (courtesy: Tallysman)

satnav 2

Petal antenna design (courtesy: Tallysman)

“If you think of a Global Navigation Satellite System (GNSS) receiver as resembling a camera, then the antenna would be the lens,” explains Allen Crawford of Tallysman. “Now, you might have an excellent top-of-the-range camera, but if it doesn’t have a clean, distortion-free, and well-focused lens, then all you’re going to get are blurred pixels that no post-processing software can fix.

“So our antenna is like a lens, except it gathers radio signals instead of light – and it is the first step in the measurement process. We want the antenna to reproduce the received satellite signals as precisely as possible, in terms of amplitude and of signal phase, on a fully representative basis, for the receiver to process.”

Available in various models and sizes, including pole-mounted, surface-mounted, and embedded versions, the VeroStar is aimed at high-performance mobile applications, such as land surveying, precision farming, maritime and autonomous vehicle navigation, typically requiring positioning accuracy down to a few centimetres.

“Different customers have differing requirements,” adds Julien Hautcouer of Tallysman. “There are plenty of GNSS antennas that work on a ‘good enough’ basis – for instance, antennas on top of cars just need to give a rough position, then the navigation receiver uses its map to estimate what street you’re on.”

“What we wanted to do, starting from scratch with this new design, for high-precision mobile users, was to be able to employ as many satellite signals from as many constellations as possible – not just GPS but also Galileo, the Russian, Chinese, Indian, and Japanese systems, plus correction service signals – and this requires good stable performance across a very wide bandwidth.”

“We want it to provide nothing but the pure right-hand circular signals, minimising any misleading reflected ‘multipath’ signals,” notes Gyles Panther, CTO of Tallysman. “We also paid special attention to the symmetry of our antenna, so that satellite signals are treated in exactly the same way, no matter where in the sky the signals are coming from. It’s like looking through a good quality wine glass when you rotate it in front of your eyes, and your view through it stays the same.”

At the same time, the modern radio spectrum is very crowded, so the design team paid particular attention to filtering out radio interference that could cause a situation where a drone might be forced down by local radio noise.

The VeroStar design is based on eight curled ‘petals’ of printed circuit boards, inspired by the post-war Alford loop antenna, which was originally designed for simultaneous transmission of multiple FM radio signals.

“The Tallysman team performed a long optimisation process using electromagnetic modelling to define the final shape for manufacturing,” notes ESA navigation engineer Nicolas Girault, the project’s technical officer. “They ended up with an inexpensive, easy to repeat process, which is ideal, really.”

The design maximises antenna efficiency and performance, adds ESA engineer Damiano Trenta: “Its rotational symmetry geometry and wideband behaviour help to provide a stable phase centre over frequency and angular range. Optimisation of the petals’ shape helps to improve the minimum gain at very low elevation angles, compared with the current products on the market, and keeps a very low cross-polar level for multipath mitigation. ”

Subsequent production line checks revealed this value remained consistent across all antennas.

The VeroStar models are now being marketed commercially both individually and as an element within customer products. VeroStar development was supported through NAVISP Element 2 – aiming to boost Member State competitiveness through the development of improved or innovative commercial products – as well as the Canadian Space Agency.

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NASA’s OSIRIS-REx mission plans for May asteroid departure

NASAs OSIRIS REx mission plans for May asteroid departure

(26 January 2021 – NASA) On May 10, NASA’s Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft will say farewell to asteroid Bennu and begin its journey back to Earth.

During its Oct. 20, 2020, sample collection event, the spacecraft collected a substantial amount of material from Bennu’s surface, likely exceeding the mission’s requirement of 2 ounces (60 grams). The spacecraft is scheduled to deliver the sample to Earth on Sep. 24, 2023.

This illustration shows the OSIRIS-REx spacecraft departing asteroid Bennu to begin its two-year journey back to Earth. (courtesy: NASA/Goddard/University of Arizona)

“Leaving Bennu’s vicinity in May puts us in the ‘sweet spot,’ when the departure maneuver will consume the least amount of the spacecraft’s onboard fuel,” said Michael Moreau, OSIRIS-REx deputy project manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Nevertheless, with over 593 miles per hour (265 meters per second) of velocity change, this will be the largest propulsive maneuver conducted by OSIRIS-REx since the approach to Bennu in October 2018.”

The May departure also provides the OSIRIS-REx team with the opportunity to plan a final spacecraft flyby of Bennu. This activity was not part of the original mission schedule, but the team is studying the feasibility of a final observation run of the asteroid to potentially learn how the spacecraft’s contact with Bennu’s surface altered the sample site.

If feasible, the flyby will take place in early April and will observe the sample site, named Nightingale, from a distance of approximately 2 miles (3.2 kilometers). Bennu’s surface was considerably disturbed after the Touch-and-Go (TAG) sample collection event, with the collector head sinking 1.6 feet (48.8 centimeters) into the asteroid’s surface. The spacecraft’s thrusters also disturbed a substantial amount of surface material during the back-away burn.

The mission is planning a single flyby, mimicking one of the observation sequences conducted during the mission’s Detailed Survey phase in 2019. OSIRIS-REx would image Bennu for a full rotation to obtain high-resolution images of the asteroid’s northern and southern hemispheres and equatorial region. The team would then compare these new images with the previous high-resolution imagery of Bennu obtained during 2019.

“OSIRIS-REx has already provided incredible science,” said Lori Glaze, NASA’s director of planetary science at the agency’s headquarters in Washington. “We’re really excited the mission is planning one more observation flyby of asteroid Bennu to provide new information about how the asteroid responded to TAG and to render a proper farewell.”

These post-TAG observations would also give the team a chance to assess the current functionality of science instruments onboard the spacecraft – specifically the OSIRIS-REx Camera Suite (OCAMS), OSIRIS-REx Thermal Emission Spectrometer (OTES), OSIRIS-REx Visible and Infrared Spectrometer (OVIRS), and OSIRIS-REx Laser Altimeter (OLA). It is possible dust coated the instruments during the sample collection event and the mission wants to evaluate the status of each. Understanding the health of the instruments is also part of the team’s assessment of possible extended mission opportunities after the sample is delivered to Earth.

The spacecraft will remain in asteroid Bennu’s vicinity until May 10, when the mission will enter its Earth Return Cruise phase. As it approaches Earth, OSIRIS-REx will jettison the Sample Return Capsule (SRC). The SRC will then travel through the Earth’s atmosphere and land under parachutes at the Utah Test and Training Range.

Once recovered, NASA will transport the capsule to the curation facility at the agency’s Johnson Space Center in Houston and distribute the sample to laboratories worldwide, enabling scientists to study the formation of our solar system and Earth as a habitable planet.

Goddard provides overall mission management, systems engineering, and the safety and mission assurance for OSIRIS-REx. Dante Lauretta of the University of Arizona in Tucson is the principal investigator, and the University of Arizona also leads the science team and the mission’s science observation planning and data processing. Lockheed Martin Space in Littleton, Colorado, built the spacecraft and provides flight operations. Goddard and KinetX Aerospace are responsible for navigating the OSIRIS-REx spacecraft. OSIRIS-REx is the third mission in NASA’s New Frontiers Program, which NASA’s Marshall Space Flight Center in Huntsville, Alabama, manages for the agency’s Science Mission Directorate in Washington.

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Inmarsat to provide satellite connectivity for UK’s first zero carbon regional air transport network

Inmarsat to provide satellite connectivity for UKs first zero carbon

(25 January 2021 – Inmarsat) Inmarsat today announced its participation in a ground-breaking new initiative funded by the UK Government to develop the country’s first automated, zero carbon regional air transportation network.

Project HEART (Hydrogen Electric and Automated Regional Transportation) will develop hydrogen powered, automated and remote piloting solutions for small aircraft carrying between 9 and 19 passengers, travelling ‘short hops’ of fewer than 500 nautical miles. In addition to its environmental credentials, the convenient zero-carbon travel option aims to enable scalability and lead to reductions in operating costs, door-to-door travel times and ticket prices.

(courtesy: Inmarsat)

Up to 100 licensed airfields throughout the UK will be made available as part of the initiative, which is expected to enter service in 2025.

Existing ‘short hop’ air travel is economically unsustainable and reliant on government subsidies to cover high maintenance and running costs. Current operations, which require two onboard pilots, depend upon expensive and polluting gas turbine powertrains.

Project HEART offers an affordable alternative that address these deficiencies with next generation technology and a ‘system-of-systems’ approach, bringing together a network of experts to re-develop the entire aviation ecosystem. As part of this approach, Inmarsat will help to power a hybrid connectivity solution that seamlessly combines its satellite communications with terrestrial networks, enabling remote ‘digital’ co-piloting and journey critical communication in the cockpit. This allows the human pilot and the digital co-pilot functions, designed by Blue Bear Systems Research, to work together effectively and operations to be managed remotely. The technology will be evaluated on Britten-Norman aircraft.

Philip Balaam, President of Inmarsat Aviation, said: “Project HEART represents a greener, smarter and more efficient future for aviation. We are proud to support this important project of the UK Government, utilising our 30 years of experience in satellite communication, navigation and surveillance for both commercial and private aviation, as well as expertise in unmanned vehicle traffic management. Working alongside our extensive network of partners, including Honeywell Aerospace, we are particularly excited about enabling remote operations for aviation networks of the future.”

Project HEART is led by the Department for Business, Energy & Industrial Strategy (BEIS) and is funded by the Industrial Strategy Challenge Fund (ISCF) Future Flight Challenge (FFC). The consortium comprises of leading UK technology companies that will contribute resources in the areas of technology, operations, infrastructure and think tank experience.

Other innovations in development for the project include hydrogen fuel cell powertrains for aircraft (led by ZeroAvia), hydrogen refuelling solutions (led by Protium), and a Mobility as a Service (MaaS) platform, with integrated sub regional flight travel mode (led by Fleetondemand), with acceptance testing headed by The Transport Research Institute of Edinburgh Napier University. In addition, architects Weston Williamson + Partners will lead on new airport infrastructure design, while the airline Loganair and Highland and Island Airports Limited will lead on accommodation of automation and hydrogen fuelled aircraft operations.

About Inmarsat

Inmarsat is the world leader in global, mobile satellite communications. It owns and operates the world’s most diverse global portfolio of mobile telecommunications satellite networks, and holds a multi-layered, global spectrum portfolio, covering L-band, Ka-band and S-band, enabling unparalleled breadth and diversity in the solutions it provides. Inmarsat’s long-established global distribution network includes not only the world’s leading channel partners but also its own strong direct retail capabilities, enabling end to end customer service assurance.

The company has an unrivalled track record of operating the world’s most reliable global mobile satellite telecommunications networks, sustaining business and mission critical safety & operational applications for more than 40 years. It is also a major driving force behind technological innovation in mobile satellite communications, sustaining its leadership through a substantial investment and a powerful network of technology and manufacturing partners.

Inmarsat operates across a diversified portfolio of sectors with the financial resources to fund its business strategy and holds leading positions in the Maritime, Government, Aviation and Enterprise satcoms markets, operating consistently as a trusted, responsive and high-quality partner to its customers across the globe.

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