One of those things which comes back up every few years - Most of the advantages of a satellite or UAV but far greater on station time and footprint. Issue include how to get it to where you want it and how to recover it afterwards, particularly the sensor/comms package.
https://www.c4isrnet.com/2022/08/11/...-spy-balloons/
UK to test Sierra Nevada’s high-flying spy balloons
WASHINGTON -- Sierra Nevada Corp., the world’s 54th largest defense contractor in the
Defense News annual ranking, will provide the U.K. with high-altitude uncrewed balloons to be used for surveillance and reconnaissance.
The U.S. aerospace company headquartered in Sparks, Nevada, will demonstrate the balloons’ capabilities as part of a U.K. Ministry of Defence’s Project Aether assessment phase contract, according to an Aug. 10 press release from the company.
The contract is valued at as much as £100 million (U.S. $121 million) and comes amid similar investments in the technology from U.S. lawmakers.
The U.K. project looks to address the country’s need for communication systems that are rapidly maneuverable for long-duration missions that require minimal resupply or maintenance. Ayse Caglar, a spokesperson for Sierra Nevada did not immediately return a phone call seeking comment.….
The U.K. ministry announced the project in December, saying it was seeking “an uncrewed stratospheric communications and intelligence, surveillance, and reconnaissance (ISR) capability with a global reach in near-real time.”….
The Army has also
explored the possibility of using high-altitude balloons to provide beyond-line-of-sight capabilities and has tested the technology at its White Sands Missile Range in New Mexico.
Demonstrations of SNC’s surveillance balloons for Project Aether are expected to take place later this year.