It looks very spectacular riding over the terrain on ATVs, exploring and collecting samples in a space suit, and living in a futuristic Mars habitat. For this to be scientifically useful, however, a lot of other, less photogenic activity has to go on behind the scenes. As with a real mission to Mars, we have to do real science, not just provide a spectacle.

This morning the ground was still sodden from the previous days rain, but the sun was shining so we knew that if we waited, conditions would be much more favorable in the afternoon. This provided an ideal opportunity for some work in the Lab.

Our habitat is equipped with a very respectable laboratory on the lower level, including microscope, autoclave, incubator, refrigeration equipment and a selection of the usual chemicals, glassware etc.

Whilst it may not rival more sophisticated establishments 'on Earth', the time and cost involved in getting material between Mars and Earth will require the first Mars astronauts to do much of the preliminary analysis of geological finds and experimental results themselves.

Even before breakfast I found Bob McNally busying himself with an experiment attempting to extract water from frozen soil obtained from outside the hab. Water in this form is believed to exist below the Martian surface, and extracting it could be a key element in allowing humans to survive on Mars.

After breakfast I found Celeste, our crew biologist, at work in the lab preparing cultures in petri dishes and placing them into our incubator. She took the time to train the other members of the crew in this procedure. Cross training is a very valuable activity in a small, isolated community. There was much excitement in the hab just now when our cultures were found to have shown signs of life in a little over twelve hours - much sooner than expected.

She has also been looking after the 'GreenHab', an on-going experiment in the biological recycling of waste liquid from the hab. This requires daily attention and communication with the 'Earth' based scientists managing the experiment.

Of course while this was going on, plans for the next EVA were already being drawn up in the wardroom.

After lunch the conditions outside were much improved, so it was once again time to venture out of the hab for more of our EVAs. We mounted two - one involving three crew members on ATVs investigating the geology to the south of the hab at White Rock Canyon, and the other a foot EVA involving two crew members, extending our geophysical survey of the area.