If you hate the format of these kinds of article let me summarize:
Guy builds an experiment, flies it, it doesn't work, requests more time to get it working, is denied, threatens 'not to come back', goes into a depression, worries crew that he'll open the door to space, eventually granted more time to work on the experiment, gets it working.
There are consequences for letting this kind of person fly and dealing with mental health while on a mission, but that's the basic plot.
Guy builds an experiment, flies it, it doesn't work, requests more time to get it working, is denied, threatens 'not to come back', goes into a depression, worries crew that he'll open the door to space, eventually granted more time to work on the experiment, gets it working.
There are consequences for letting this kind of person fly and dealing with mental health while on a mission, but that's the basic plot.