The mass budget constraint
Why is the first climber limited to 900 kg?
Because the pilot ribbon is the largest that can fit in the Shuttle’s cargo bay
The pilot ribbon can only support a 900 kg climber
If we can’t build a 900 kg climber, then the pilot ribbon needs to be larger which means it can’t be boosted to LEO with the Space Shuttle
Everything gets more expensive then
What can we boost the pilot ribbon with?