I don't know how relevant that is. That's something that can be done by an individual, training for something slightly slower than 4 minutes and pushing through to achieve a time that onlookers might not have expected.

The real friction in building a reusable rocket isn't the engineering, it's setting "let's build a reusable rocket" as a design goal, and getting a whole bunch of engineers and a whole bunch of dollars to start on that goal.

You have to start with a whiteboard sketch and board-room presentation that shows it's achievable, and then send the engineers out to refine the sketch into something worth funding, and then work for months or years to build a rocket that would be a disaster if it's not achievable.

>Proof of concept. It's a lot easier to do something, if you know it can be done.

This.

What I wanted to emphasize was how, after Bannister finally broke through the 4-minute barrier, many others did it soon after: 3 more in 1954; 4 in 1955; 3 in 1956; 5 in 1957; 4 in 1958.

List: https://imgur.com/a/UadE3xa