Even those with the tidiest of workshops sometimes misplace or loose their tools. You are distracted by something else or forget to put it away and when you come back you just can't find it. You can of course mitigate this problem by having a proper place for things and ensuring you always put things away at the end of the day (even it your dinner is getting cold).
However life is not so straight forward for astronauts. Whilst cleaning grease off her gloves, mechanical engineer and seasoned astronaut Heidemarie Stefanyshyn-Piper let her toolbag slip and was forced to watch as the tools (apparently worth £70,000) float away. Astronomers from around the globe have the oppertunity to try and spot the toolbag but I'm not sure they'll be able to do much to help if they see it.
Read more about space at the bbc
2 hours ago