As of May 5, 2019, here is a list of processes and parts that we want to be able to make that we either haven't gotten around to or have done with less-than-ideal results.
Nose Cone
| Work to Do (important stuff to figure out so we can grow as a team!) | Work Done So Far (use this as a guide but take this with a grain of salt) | Suggestions for how to proceed |
|---|---|---|
| Figure out the ideal composition/amount of ablative to apply on the nose cone by conducting rigorous thermal testing | Currently use Fibreglast Systems 3000 epoxy with 15% by weight of phenolic microballoons. Can thin this mixture with acetone if needed. Have conducted some thermal tests on different samples and mixtures but testing wasn't super rigorous (i.e. uneven layers of ablative, samples weren't super flat, etc.) | Make several test samples of different types (fiberglass, CF, etc.) and thicknesses of materials, and different types of ablatives (i.e. vary the amount of phenolic added, use different types of epoxy, maybe add other materials like chopped fiberglass, etc.) and point a heat gun at it, and measure temp of each side using thermocouples |
| Apply ablative coating evenly to a nose cone, whether in the mold before the layup or afterwards | Hermes 2 NC attempt #1: applied ablative in the mold. This didn't go well because the layer was pushed around and stuck to the mold after separating the two halves. Hermes 2 NC attempt #2 (flight NC): applied ablative after separating NC from mold by supporting the nose cone on the layup jig, applying ablative and using a heat gun to speed up the cure time while turning the nose cone like a pig on a spit. Result was better but still uneven. | Test different coating methods on nose cones that we already have in lab and don't care about (methods could include the "spit" method described in the column to the left, spraying epoxy from a spray bottle, coating in the mold, etc.) |
Fin Can
| Work to Do | Work Done So Far | Suggestions for how to proceed |
|---|---|---|
| Figure out how many layers of carbon fiber we actually need on the fin can using equations, not just intuition (contact professors and other experts) | Some sketchy math | Reach out to professors (both from MIT and other schools), as well as other rocketeers like Jim Jarvis and Derek Deville |
| Contact Prof. Drela to figure out how to do fin can layups better | Got a lot of good advice from him on nose cone layups, but haven't asked about fin can layups yet. | Talk to Prof. Drela! He knows a ton about layups. |
| Design a better static load test with a rigid jig to properly test how strong each fin is and the overall strength of the fin can | Did one static load test on the test carbon fiber fin can we made applying a load on the end of one fin (Hermes 2 Fin Can #1) but the jig wasn't super rigid (was made out of 80/20 and the whole thing rotated, so we're not sure how good the data from that test is. We decided to go ahead and fly the flight fin can (Hermes 2 Fin Can #2) using the info from the test fin can | Take time to design a good jig that allows you to test a single fin (either on its own or attached to a fin can). If you want to test the strength of the fin can as a whole, do more research because we haven't figured this out yet. |
| Determine whether we should use honeycomb fins (or some other material) | For Hermes 2, we used fins made out of G10 (a type of fiberglass) with a phenolic piece that slotted onto the leading edge. Other materials might save us mass while adding strength, such as honeycomb. | Make test fins out of different materials and conduct tests on them (thermal, structural, etc.) and compare masses to make a decision. |