Well, quite a few of my experiments don’t work, so I guess that is them going wrong! Most of the time, you just have to start again, and if you know what went wrong the first time, you can fix it, the difficult part is when you don’t know what has gone wrong, as it can be really frustrating! It’s part of being a scientist though, trying to troubleshoot things, and solve problems! I prefer it when things go right though!
Two things: (1) you learn from it (by finding out why it went wrong – sometimes that can tell you something that you didn’t know before) and, if it was just an accident, (2) you do it again, if you can.
But that’s not always possible: if your experiment has to be done in a particular place in the deep ocean, for example, and it doesn’t work, you might not have the chance to get back there to try again in another expedition. So in my work, we often only get one shot at getting it right.