Last night ended up being slightly more exciting than anticipated. Randy and Danielle spent several hours trying to clear water that had flowed back from the grey water tank to a place where it shouldn't have been. We didn't want the air conduit containing that water to freeze overnight, so we spent a lot of time removing all the water that we could with a Shopvac. We were interrupted in this task by an LP gas leak alarm, which led us to frantically evacuate the Hab and then go shut off the valve on the propane tank out in the engineering area. Then as we were waiting for the gas fumes to dissipate through the Hab's open airlock, each one of us fretting about the possibility of the Hab exploding at the slightest spark generated by the equipment that we had left on inside, the alarm was revealed to be an elaborate conspiracy between Paul and our HSO Melissa. They had put together this hoax in order to create a realistic Hab evacuation drill for us. The LP alarm that went off actually hadn't been there 30 minutes before; Paul had taken advantage of the usual frenzy in the Hab to install this gas detector, in a slightly mis-wired configuration, without any of us noticing.

After we came back in from this evacuation drill, we entered our "full sim" mode. This means that we are no longer allowed outside the Hab unless wearing an EVA suit, except to go to the GreenHab, to the engineering area or to the observatory using the "pressurized tunnels" that are there for us. Also we are no longer eating any food that wouldn't be available to us on Mars.

This morning we had a bit more excitement when our commander Lealem found a mouse in his suitcase. Armed with a bucket and an old margarine container, Lealem and Jon were able to get it out before it could leave traces in Lealem's possessions.

After the mouse problem was taken care of, Lealem, Jon and Olathe headed out to the salt fields above Radio Ridge in the first real EVA of our rotation. They collected samples for Olathe's research and upon returning to the Hab they did a bit of ATV training for Jon. Jon is our only crewmember who's never served on an MDRS crew before and it seemed like a good idea to show him what it's like to ride an ATV while wearing an EVA suit.

In the afternoon, Melissa, Randy and Danielle headed out east of the Hab on another scouting EVA. They found a few very interesting things, including what looked like dinosaur bones. A few samples from salt fields were also collected for Olathe's research.

This evening will be spent writing reports, doing an EVA debrief and participating in presentations on the radio communications protocol and on the Field Documentation Methodology (FDM), which will be given by Danielle and Randy, respectively.