Stratospheric Platforms chief executive Richard Deakin told iTWire in response to queries that the High Altitude Platform would be able to stay aloft for nine days.
"Only one HAP is required to provide the service, but some customers may want to ensure that they have a very high level of service assurance, so much of the modelling we have done assumes a spare HAP for each one on station, or a spare HAP for say three HAPS on station etc," he said.
"At hand-over, another HAP would position itself in the same orbit as the HAP providing the service, and the HAP in need of refuelling would return to base, so there would be no break in coverage."
"One phased array antenna delivers hundreds of beams onto the ground, each equivalent to a cell created by traditional terrestrial masts."
An artist's concept of the HAP flying over mountains. Courtesy Stratospheric Platforms
Deakin said the endurance of the HAP had no connection to its maintenance, repair or overhaul needs, it was only determined by the need to refuel. The HAP is estimated to have a lifespan of 10 years.
Asked about costs, he said the company had done extensive modelling on both capital and operating costs.
"The exact details very much depend on the use case requirements. However, all modelling confirms that the deployment costs are a fraction of those associated with the cost of terrestrial masts, not to mention the significant improvement in coverage," he said.
The technology will be sold through telecommunications providers and will be targeted at ordinary consumers, with Deakin including businesses in that definition. "Satellites could be a solution for some applications, but of course you can't connect your smartphone to a satellite," he pointed out.
"One of the telecoms companies we are working with has calculated that our system can provide 600X more data per square kilometre than would be possible from a low-earth orbit satellite constellation (not to mention the very high data latency from a satellite which will not suit many real-time applications such as autonomous vehicles and drones)."
Regarding government assistance for the project, Deakin said it was a work in progress and was subject to compliance with the regulations of the WTO and the EC, among other bodies.
There have been rumours that hydrogen is not safe to be used as a fuel - much in the same way that myths about 5G being responsible for COVID have spread - and these often affect take-up of technology.
Asked about this, Deakin said: "Interesting question. Naturally we are keen to have public support. Clearly there is no link between 5G and COVID (in fact, many 4G frequencies are the same as 5G today). I guess we are planning around science rather than myths."
Work on testing the HAP is expected to be completed in 2022 and the technology is expected to go on sale in 2024. Stratospheric Platforms is working with Spirit Aerosystems, Cambridge Consultants, Deutsche Telekom, Pankl Turbosystems, Qinetiq, Scaled Composites, Thales, TWI and IAV Automotive Engineering to get things up and going.