Solar cooker failure

So our last solar cooker broke and falled. We are working on a new one now but my group mates aren't working on it because they have had a lot of make up work becuase they were sick. We haven't had a clear plan on what we are going to do. Our first solar cooker is going to be used for spare parts if we need it but we need a new desgin. We hope to make just a regular box cooker and make modifications. We only have about 3 more weeks until the cook out and we don't have any data on a solar cooker. Can anyone give me suggestions on what we should do?