• Prior to a launch, a large amount of Helium must be pushed into the WIP vehicle’s inner cells
• The fill tubes must be securely connected but should also be easily removable from the vehicle
• The Autofill system was designed to control and monitor the amount of helium that is pumped into each of the inner cells of a WIP vehicle
• This system was tested multiple times in float tests and flight tests of the Ascender 28 vehicle
Ground Handling of
Large Vehicles
• Airship vehicles are relatively lighter than satellites. Managing these vehicles when they are on or near the ground is critical for safe and effective operations
• Avealto successfully managed ground handling with the Ascender 28 testing
Wind Barriers
• Wind barriers could be used at launch and landing sites to reduce the wind effect on WIP vehicles when they are not in a hangar
• Avealto built a test wind barrier in The Black Rock Desert, Nevada, USA. This wind barrier allowed Ascender 28 to remain on the ground safely for long periods
• Avealto has developed practical techniques to allow low-cost methods of building wind barriers
Solar Panels
• Key supplier for thin film solar cells has been identified
• Solar cells solar on the WIP vehicle are expected to be exposed to direct sunlight above the clouds and very cold temperatures for long periods. A-SI type Thin Film Solar cell system from this key supplier was successfully tested at high altitude in May 2016 with a balloon flight
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Batteries
• Avealto has identified a battery vendor based in the US which could provide batteries with 450 watt-hours per kilogram of weight
• Avealto is working with this vendor and a battery management system specialist to complete the battery pack design to be used on the commercial WIP vehicles and expects to sign a long-term supply agreement with this vendor by the end of May 2023
Avionics & Autopilot
• Autopilot System expected to be used on the full-size commercial vehicle was tested and on 1/8 subscale vehicle to calibrate it with the vehicle control systems. The tests verified the software and command changes that were integrated into the autopilot system worked well and were able to manage the vehicle
• A second subscale vehicle (17m long – 1/6 scale) is likely to be tested with this same autopilot systems on board from April to June 2023 under the supervision of the UK Civil Aviation Authority (CAA). This vehicle has the same avionics and control systems that would be used on board the full-size commercial vehicle
• Avealto filed a patent in July of 2022 about the autopilot command and control software
Subscale Vehicle
Testing
• In November and December 2020, Avealto conducted a series of tests using a 1/8 subscale vehicle built to the same proportions as the planned commercial WIP vehicle
• Tests were conducted in the Brabazon Hangar in Bristol, UK. The tests provided insights into vehicle handling during launch and landing and the ability of the vehicle to maintain a stationary position
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Telecom Payload
• Telecom Payload development is being conducted in partnership with UK-based ELT Systems
• Avealto has already invested significant effort and funding in the Telecom Payload development. Initial payloads for the Indonesian market are likely to use Ku-band transceivers. These Ku-band transceivers are expected to be tested on a subscale vehicle to be flown from April to June of 2023
• Telecom Payload is designed to operate with different frequencies as needed in different locations of the world and to allow additional capacity in the future
Antenna Design
• The Telecom Payload and related antenna are likely to be unique as no one has previously operated a vehicle for long periods in a stationary position in the stratosphere
• Avealto invested significant time and resources in antenna design development. Advanced computer simulations were used to predict antenna performance. Avealto filed a patent on their novel antenna design in July 2022
Envelope Material
• Avealto has developed a very lightweight and strong solution for the plastic fabric that would comprise the outer envelope of the vehicle
• This material is 20% stronger than Kevlar by weight and would have a reflective coating to reduce heat transfer during daytime operation
Components (4/8)
Inner Cell Material
• The inner cell material would hold the helium gas that provides lift
• Commercial WIP vehicle is likely to have multiple inner cells to avoid the “sloshing” of the helium gas during the launch and landing of the vehicle
• Avealto spent several years testing the best combination of plastic film and coatings to find the optimum Inner cell material
• Permeability tests were conducted by Versaperm, a UK test lab specialising in gas permeability testing
Aerodynamic
Analysis
• Avealto conducted multiple Computer Fluidic Design studies to determine the optimal aerodynamic shape of full-size commercial WIP vehicles. These studies included the calculation of the vehicle in different flight configurations and conditions
• Avealto is working with Rand SIM to optimise the design of the vehicle body, thermal management and propellers
Material Stress
Testing
• Avealto WIP vehicle is expected to operate in the harsh environment of the stratosphere for long durations
• Low-temperature stress test has been conducted on the outer envelope and inner cells
• Inner cells have been lab tested to determine the level of impermeability to helium. Test sections of the carbon fibre keel are expected to be built and tested in the next few months
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Aerostructure
Design
• Aerostructure or Keel of the WIP vehicle would likely hold all the electronic systems, batteries, and ballast
• Side Pylons are attached on both sides to hold the Propellers
• This Aerostructure must be lightweight but strong. It is expected to be made from specially designed carbon fibre to withstand the stresses that it encounters in flight
• Auriga Aerospace designed the carbon fibre keel, a key component for the WIP vehicle
• Norco Composites Ltd. has been selected to produce the carbon fibre keel and has already begun preliminary tooling
Propulsion and
Manoeuvring
• Avealto WIP vehicle is expected to be propelled by four electric motors (two on each side)
• A comprehensive propulsion study was conducted by Auriga Aerospace Ltd. to determine the amount of energy required to operate the vehicle in different wind conditions and during launch and landing
• A test motor is expected to be acquired in Q2 2023 to test in a thermal / pressure chamber which would emulate the temperature and air pressure conditions at 18 to 20 km altitude
Thermal
Management
• Air temperature at 18 to 20 km altitude is -50oC to -70oC. The batteries and electronic systems onboard the WIP vehicle are optimised to operate at much higher temperatures
• Electronic systems, including the avionics, Telecom Payload, and charge controller, generate some heat
• Compartment within the carbon fibre keel where these systems are housed has been designed to utilise this heat generated by the electronic systems to maintain a comfortable temperature for the batteries and other systems
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Altitude Control
• To provide a continuous communication link, the WIP vehicle must stay in the same position with respect to the ground at all times
• During the daytime, the vehicle would absorb energy from the sun, likely increasing the lift of the vehicle. To compensate for this lift, outside air would be pumped into a ballonet inside the outer envelope
• This compression in the outer envelope is expected to offset the lift caused by solar heating during the day. At night this internal pressure is expected to be reduced
• Avealto has developed the design and identified a vendor for the compression system
Propeller Design
• At 18 to 20 km altitude, the air density is only around 6% as much as at the sea level
• A specially designed propeller would likely be needed to allow the electric motor’s energy to be efficiently turned into propulsion
• This propeller is expected to be designed through a sophisticated Computer Fluidic Dynamics system managed by Rand SIM
Antenna Gimbel
• Telecom Payload design for the initial fleet of WIP vehicles includes multiple “spot beam” antennas to provide optimum coverage within the 240 km diameter coverage area of each vehicle
• These antennas would be housed within a Radome on the lower keel of each WIP vehicle. These antennas must always be pointed to the same locations on the ground to provide continuous a communication link with ground stations
• Avealto has identified a Paris-based company, XD Motion, to provide this gimble. The gimble design is expected to be tested on the 17m subscale vehicle to be tested in Q2 2023
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Vehicle Testing and
Certification
• UK CAA is an internationally respected aviation operation and safety regulator. It would monitor the testing of Avealto vehicles and will have the authority to issue flight approval for the Avealto WIP commercial vehicle
• CAA-supervised testing of the WIP commercial prototype is initially likely to be conducted at lower altitudes to confirm the safe operation of the vehicle
• Testing is expected to be conducted at designated flight test ranges in the UK. The test range operator would supervise the testing under the CAA criteria and regulations
• Avealto has engaged expert consultants, including Across Safety Development Ltd., to work with the CAA and its engineering team, to ensure that the Avealto WIP design is fully tested before certification
Commercial
Prototype
• In the fall of 2020, the Avealto design team determined the dimensions of the initial WIP vehicle design
• Avealto WIP vehicle is expected to be 101m long (330 feet) and 17m (55 feet) high
Final Subscale
Vehicle Testing
• To complete the final design details, a subscale 1/8 size subscale vehicle has been flown indoors, and a 17m long (1/6 size) subscale vehicle is expected to be flown in Q2 2023 to include free-flying test tests under the supervision of the UK CAA, at Snowdonia Aerodrome in Wales, UK
• This is expected to be the final test of smaller vehicles before setting up production for full-sized commercial vehicles
Components (8/8)
Fleet Operation
• Avealto is planning to build and operate more than 200 WIP vehicles
• To manage the vehicles in flight in different parts of the world, Avealto has developed a comprehensive “Concept of Operation” plan to be implemented before beginning commercial operations. This plan is expected to ensure that WIP vehicles would be able to operate safely at all times
Telecom Payload
• Telecom Payload, designed by Avealto, is being developed in the UK by ETL Systems Ltd.
• Designed to operate on multiple frequency bands to be able to serve multiple market segments on a single WIP vehicle
• Total weight of the radio and antenna system is designed to be 55 kg (121 pounds) or lesser
• Amount of transmission capacity onboard each WIP vehicle would have a direct effect on the amount of revenue that vehicle could generate
• Initial Telecom Payload design is likely to use passive antennas to provide a “bent pipe” satellite design. The first version of the payload is expected to provide 20 Gigabits of capacity
• With the Avealto WIP, it would be possible to incrementally upgrade the radio and antenna systems on board each time it lands for servicing
• Telecom Payload went through a preliminary design review in March 2022 and is expected to complete the Critical Design review by July 2023. A Telecom Payload transponder is likely to be tested on a subscale vehicle in Q2 2023
Key
Vendors
Key
Certifications
Avealto received US FAA
Airworthiness Certification in 2017
• Requirements for this certification are more stringent than the UK CAA certification
• However, Avealto was able to easily obtain this certification from the US FAA
• Thus, Avealto believes it can also easily obtain the UK and Indonesian flight approvals
