In the Classic column Can I declare a no-flight zone over my house, The Great One states that national airspace is officially declared to end at, and outer space is officially declared to begin at, around 90 km of height, which is “out of range of most nations’ guns.”
MOST nations? What nations have guns that can shoot 90km high?
Holy moly. I’d heard of Gerald Bull and the Iraq thing, but I had no idea guns had actually been built that would fire that high. I thought the ‘supercannon’ was just another one of those whacked Great-Dictator-type ideas that no-one around the dictator dared question…
Even Germany in WW1 had a cannon that could probably reach 90km, assuming you reduced the mass of the projectile and aimed higher. The “paris gun” (a misnomer, as there was more than one) could fire a 120kg payload about 130km downrange, reaching an altitude of 40km during the trip. Change that to a 10kg payload and you might have an International Space Station gun.