Last night I had a dream that I was on a ship to mars. Ground control had us constantly compressing air into canisters, and assembling them into big rings, which were then attached to the spacecraft to boost propulsion. Apparently they had miscalculated the amount of fuel needed for the trip, which was why we were all busy doing this.
One of my comrades started flipping out. He thought that they had us doing all this work just to keep us occupied on the three year journey, in order to stave off cabin fever. I thought he was right, but that for precisely that reason we should keep doing it.