“There was a fascinating struggle between those of us who designed the different biotopes and those who were to live there later on. In the real world, there are insects that eat leaves. But we would not have insects that ate the crops. We were 20 people discussing the problem.”

  WHAT WAS THE FIRST DAY LIKE?

  “Suddenly, I could not hear anybody hammering or talking. That was when I realized that from now on, it was up to us. Everyone who lived in Biosphere 2 had also participated in the design and construction of it. Naturally, that produced a special atmosphere. It was our project.”

  DID YOU HAVE ANY TIME AT ALL FOR SCIENTIFIC WORK?

  “I think we spent one-third of our time planting crops and cooking and only 5 percent on research. We spent way too much time trying to find solutions that could provide us with more food.”

  HOW DID THAT AFFECT YOU?

  “At 4 p.m., I was exhausted and had to lie down on the floor. We didn’t have enough energy to solve the problem that we didn’t have enough energy — it was a vicious cycle. I belonged to the group who believed that we had to make it no matter what. Others said that, from a scientific point of view, it was not all that interesting to prove that it is unpleasant to be hungry. The food problem split the group in two. I had been sailing around the globe with these people and, suddenly, I opposed them. It lasted for the last 18 out of 24 months. Today, I am impressed that we did not turn to violence.  We managed to avoid that."

  ON ONE OF THE FIRST DAYS, YOU CUT OFF PART OF YOUR FINGER ACCIDENTALLY. THEN CAME THE SPLIT AND HUNGER. DID YOU EVER CONSIDER QUITTING?

  “Never. None of us did. After having prepared for years, we were dedicated. We probably stayed together because we all wanted what was best for the project. We just did not agree what that was.”

  LOOKING BACK, WHAT DID YOU LEARN?

  “Biosphere 2 is a key footprint for science, not least concerning the psychological aspects of space missions. The crew would probably be fine on the way to Mars because they are so busy. But the way home will be very hard. Nine months in a sealed spacecraft — wow!”