 I'm Dave Rothery, Professor of Planetary Geosciences at The Open University, and we're working with many colleagues on sending a probe called BepiColombo to Mercury. Now, when you get there, you're three times close to the sun than you are on the Earth, so you've got the sun sending 10 times the energy to you that you get at the Earth. On the other side of you, you've got a planet, and if you're on the noon side of the planet, you've got this damn big planet at 450 degrees centigrade, you've been baked from both sides. It's a very hostile environment to send a spacecraft to, so we've got all kinds of clever radiators to try and get rid of the heat and a wonderful device called a cold finger, which sucks the heat out from the inside and radiates it to space. It's a very, very complex place, a difficult place to be, but we know it can be done.