One of the truly horrific tragedies of NASA's history. Even more horrible when you are aware of the finer details behind the event. Challenger was initially schedule to launch the previous day. I was at home on vacation that day. I was monitoring the launch with my C band satellite dish with a direct NASA feed. What delayed the launch was a stripped bolt on the hatch. They had numerous teams working on the problem. Both the white team, and blue team both failed to extract the bolt. One team showed up with a portable drill that hadn't been charged. The next with a corded drill that didn't do the job. At one point I saw several of the launch crew crowded around the hatch while one crewman worked on the hatch with a crow bar. Unbelievable I was shocked at these antics. Any way the launch window was missed. I went back to work at the television station I was employed at the next day, and sauntering through master control i saw the horrendous explosion on several monitors. It was a tenfold tragedy as I knew the unfortuitous chain of events that had transpired the day before. If the Challenger had been launched the day before it would have escaped the freeze that damaged the solid rocket booster O rings during the night.