In this short video, I determine that firecrackers can be ignited and will explode in a vacuum. An interesting side effect of being in a vacuum is the essential elimination of noise from the explosion. Because there are so few gas molecules present, a sound wave cannot propagate and the "TING" noise you hear in the video is actually just shrapnel hitting the viewport glass (which is exactly why it sounds like someone tapping on a wine glass).
Another interesting effect is the resultant smoke and dust cloud creates a unique plasma. A strong beam of ionized particles and macroscopic pieces of dust can be seen in the bottom where the positive electrode is. This is due to the large amount of positive ions being ejected out of the electrode region.
Another interesting fact is that it actually took about 2 minutes for the firecracker to ignite even though the plasma is extremely hot (many thousands of kelvin). The reason for this is that the plasma is mainly composed of very light electrons which have very little heat capacity. So even though these 10000 K electrons are striking the firecracker and fuse, they conduct very little heat to it so it takes a very long time to ignite. An additional point is that the electrode is fairly large so these hot electrons are spread out all over the metal. I did concentrate them to some extent by choosing the geometry that I did (as evident by the dense plasma after the firecracker explodes) but it still takes a decent amount of time for it to heat up.
