For those wondering how hard it is : More people have traveled to space than have summited K2 in summer [1].
[1] https://www.mountainfilm.org/media/breathtaking-k2-%E2%80%93...
[1] https://www.mountainfilm.org/media/breathtaking-k2-%E2%80%93...
It is at the very least an order of magnitude more dangerous than space flight.