TURN is Flying Outdoors

HAPS is Still Seen as an Ideal Telecom Solution

A recent article in Space News described High-Altitude Platform Stations (HAPS) as an ideal solution for telecommunications which overcomes many of the deficiencies with LEO-based architectures. It described that "initial direct-to-smartphone services provided via Globalstar, Lynk Global, and others in the works are for low-bandwidth applications such as SOS alerts and text messages" and illustrates how Starlink's latency can't compete with that of an aerial platform operating within the stratosphere. Finally, it outlined Google's stratospheric balloon project, where "Loon first provided commercial connectivity in 2020 with dozens of balloons equipped with payloads mimicking cell towers, only for the plans to burst a year later because it couldn't create a long-term, sustainable business" from logistic complications around retrieving the balloons.

The publication also describes the current HAPS frontrunner, Aalto Zephyr, where the article outlines some of the most pressing shortcomings. "Aalto requires reliable access to the stratosphere to get its lightweight glider off the ground, and... this isn't guaranteed anywhere." Further describing Zephyr, "Today's batteries last 90 charge cycles" and then goes on to state that "the aircraft would need to be swapped out with another Zephyr so it can land to replace batteries."

Conversely, a major benefit of TURN's increased aerodynamic efficiency is that the vehicle was sized with more robust Lithium-Ion and Lithium-Polymer batteries which already have commercially available products demonstrating 500-1000 charge discharge cycles. So, TURN's batteries would only need to be replaced every 18-36 months.

TURN has a distinct advantage over Zephyr on its performance once on-station, but it also overcomes a major challenge with other HAPS aircraft: ascent and descent. In Zephyr's last flight demonstration back in 2022, their aircraft was "stuck" in the stratosphere, where lower altitude winds were too strong for the aircraft to descend and arrive at the airfield. Devorto's latest Space Force SBIR proposal highlights a distinct advantage with TURN, because it only deploys the tethers once on-station. The tethers are retracted during takeoff and landing which offers a very compact system spinning at a higher angular rate, providing additional wind robustness from its gyroscopic stabilization.