I remember reading the science fiction novel "Armageddon 2419 A.D.”[1] by Philip Francis Nowlan and it’s sequel "Warlords of Han” when I was younger. I remember a floating “eyeball” drone that could fire a missile in the novel, and it looks like NTT DoCoMo is working on something along those lines[2]. It will be interesting to see how this develops.

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[1] “Armageddon 2419 A.D.”, Nowlan, Philip Francis, https://en.wikipedia.org/wiki/Armageddon_2419_A.D.

[2] “NTT Docomo ballon drone gets around using ultrasonic propulsion”, https://newatlas.com/drones/ntt-docomo-balloon-drone-ultrasound-propulsion/