The first vertical test shot of Green Launch's hydrogen-powered impulse launch cannon. The hydrogen cannon can be fired…

The first vertical test shot of Green Launch's hydrogen-powered impulse launch cannon.

The hydrogen cannon can be fired every 60-90 minutes, sending its hypersonic projectile skyward where it'll "penetrate the atmosphere within a minute and shed its aeroshell." Low earth orbits between 300-1,000 km (186-621 miles) can be achieved in under two hours, and some much quicker.