Simple full time civilian here but some links here prompted me to read up on flying the U2. goodness me what a dangerous occupation flying the U2 is and yet the loss rate from such an unstable and unforgiving aircraft ( thats a really scary phrase when you think about it) has been in regular use for decades . total respect for those who fly and maintain it.
Not many jobs where losing concentration (which must be tempting with the amazing views they get) for a moment sends you into an unrecoverable dive/spin/spiral. Extraordinary