So if you haven't heard, a rocket that was supposed to bring supplies to the International Space Station (ISS) exploded on October 28. Here's a short article and video talking about it: http://www.wired.com/2014/10/antares-rocket-explosion/.
Obviously, this kind of sucks. The rocket cost about $200 million and now most of the supplies won't make it to the ISS. However, explosions are still really fun to watch, especially one that big and I don't feel bad saying that since the rocket was unmanned.
Also interesting is that the rocket was made by Orbital Science, under contract of NASA. This shows that the space industry is slowly because more of a private industry with Orbital Science and SpaceX leading the way at the moment.
They aren't sure exactly what caused the rocket to fail, but the actual explosion was caused by the self-destruct being purposefully activated. The real problem was right when it fired its first stage - you can kind of see this in the video. As soon as this problem was noticed, it was decided to destroy the rocket before it reached a populated area and could potentially cause damage.
Any number of factors can mess up a rocket launch; there are a lot of variables. Wind speed and direction, an area clear of people, weather, calculations, etc.
I think the biggest things I learned from this are that those errors we usually don't account for in our physics labs (FRICTION!!) matter a lot in the real world, and that we still have not perfected going to space.
I'm excited for space tourism anyway.