> using mostly existing designs so there was no technical risk. If only that was so. Using a bunch of old tech in a new way does not actually lead to great suc

> using mostly existing designs so there was no technical risk. If only that was so. Using a bunch of old tech in a new way does not actually lead to great success. The re-qualification of the RS-25 alone took years and cost 100s of millions. And that is without producing new ones.