I'm watching Apollo 13 and...

It could be argued that the Challenger disaster was one of the biggest setbacks for space exploration. Up until that point there was a lot of joint work between NASA and DoD. After Challenger the Reagan administration ended that. On the surface it could then be argued that decision was partially to blame for the loss of the Columbia crew. Ending the use of NASA assets for DoD missions resulted in many fewer NASA people with security clearances. At one point while they were evaluating options for Columbia after knowing there was damage, but not knowing the severity, they were trying to figure out how to get a better look. One civil servant I'm aware of was fully aware of essentially every satellite in orbit and their capabilities. He knew there were vehicles available to look at the damage, and knew where they were with respect to the shuttle. However there was no one in the shuttle program with appropriate clearance to even know some of the satellites existed. In the end it wouldn't have mattered, most likely. There was not another shuttle ready, and there was no way to get Columbia to ISS, because they were on very different orbits. I don't remember if it was a finding publicly released in the CAIB (Columbia accident report), as I was more concerned with a report from the crew perspective about evaluating survival possibilities from Challenger an Columbia, but there are a lot more people with Clearances sr NASA again.