Step 3: Trimming the Tubes Further trimming slims the tubes down. They will now both fit, side-by-side in a glass terrerium recently purchased for several dollars at a yard sale. The goal for our final display is to allow a different view from all four sides as well as from above. Two tubes were constructed to achieve this. The first was a single-balloon unit with a "skylight" opening left in molding process to illustrate this common entrance feature. It will be viewable from the left side of the case. On the right, sits a second tube that was constructed with two balloons, placed at an angle to one another. The result is a longer tube, with other features, including a roof-top "hornito" opening. This longer tube has both ends cut, offering a view from that angle. From the top, the hornito spatter cone and adjacent skylight will be visible. With both foam tubes sized for the terrerium, a suitable mold will be constructed around the two tubes to allow for the filling in with more foam, of the rest of the "ground." A wood frame covered with sheets of plastic will be used. All the openings and cut edges will have a bead of minimal expansion foam applied before putting the wood mold around them. This will guarentee that our tubes do not get filled in. If all goes according to plan, we should end up with a block of foam, slightly smaller than the terrerium, so that it can be placed over it up-side-down for a finished, professional-looking case. To the top "surface," craters will be constructed to mimic a typical lunar location. The Caves of Mars Project is funded by a NIAC Phase II Grant from the NASA Institute for Advanced Concepts. Copyright © 2002-04 - Complex Systems Research; Inc.