Some might be tempted to wonder, why have a single person dedicated to speaking with the astronauts at all? Why can't the flight director or Mission Control as a whole just speak to the astronauts? Well there are a couple of reasons. First, it makes sense for there to be a single point of contact with the astronauts, someone with whom they can build up a rapport. That way, they always know information is coming to them through a single channel - this removes the potential for conflicting instructions. Secondly, mission control can be a bit of a crazy place, even with the FD directing traffic, and it takes a special skill set to be able to filter through all the information passing back and forth. A stellar short term memory and an ability to understand what directives are simply proposed and which have been decided is definitely a requirement. I stepped in when Melissa had to leave the room and I can tell you - her job was not an easy one!
There is another more subtle reason that the CAPCOM role exists, by having a person dedicated to communicating with the Astronauts, they gain an advocate at Mission Control. It is for that reason that CAPCOMs are typically current or former astronauts themselves. They can put themselves in the shoes of the astronauts who, in turn, know that the CAPCOM understands their plight. Melissa was an excellent candidate to fulfil that role precisely because she has had so much experience simulating Mars missions in the past. That exploration is part of what makes her interview with Alyssa Gilbert so memorable.
But you can't forget about the science either, and Melissa was kind enough to share with us - and with you - her expertise with extremophiles that live in the high arctic in complex chemical environments. I hope you enjoy the interview as much as I did. If you didn't have the chance to listen on Monday over at Astronomy.fm you can download a copy over at the Western Worlds webpage. And as always, my intro is under the cut.