Ad Astra PDR Notes

Owned by Donovan Barros (RIT Student)
Nov 09, 2024
2 min read

Avionics

  • Don’t say eliminate all points of failure

  • Consider how avionics structure integrates with regular structure

  • Failsafe feature is irrelevant on Eggtimer Quantum

  • Clarify and make sure pro vs con for cost and owned are consistent with flight computers

  • Consider combining different flight computers to satisfy requirements

  • Know what the safety features are for the Eggtimer Proton

  • Don’t say the TX is slightly larger than the mini if it is 2x the size

  • Don’t listen to nate about the featherweights

  • Consider RS41 Radiosondes

  • Low self-discharge rate for batteries doesn’t really matter for this application

  • Don’t say low energy density when no sizing has been considered yet

  • Consider leads on your batteries

  • Consider LiPo rectangular

  • No safety for over-discharge?

  • Lion discharge rates can vary

  • Don’t buy batteries without leads

  • Don’t use batteries in a holder because spring connections are prone to brownouts

Payload

  • Define immediately searchable area

  • Test successful deployment in any orientation

  • Consider volume and correct geometry of model rocket

  • Consider max height of rocket

  • 3D printing tolerance should not be an issue as long as its accounted for

  • Consider how you would glue sabot leaves together

  • Try and use the Prusa XLs for sabot printing instead of BigRep

  • Can combine sabot and spring release design options

  • Consider more details concerning priming and constraining the spring

  • If using streamer, we know Cd for the material and manufacturing style if copying IREC

  • Featherweight is probably too expensive

  • Need to test more with FUVISION camera

  • Estes cam has 40 minutes of battery life

  • Henceforth the mini rocket will be referred to as little bro

Recovery

  • Use Sondehub weather calculations

  • Avionics integration with tender descender

  • Write out descent rates on reefing slides

  • If using Kong Streamer, it is safer to assume Rocketman Cd is accurate

  • Don’t use elastic line (please)

  • Consider how the main chute is constrained at apogee deployment

  • Will be a challenge to do that

  • Swivel link benefits are hotly debated

  • While a single streamer may be the easiest method for recovery, it does not prepare you as well for IREC

Structures

  • Apogee goal is a team-set requirement, not in the design requirements document

  • Check max URRG height

  • Plywood bulkhead image contains 3D geometry that is not able to be laser cut

  • Possibly consider G10 fiberglass bulkheads but also know that this would be more expensive

  • URRG won’t get hot enough to warp PLA

  • External layup on 3D print nosecone could be an option

  • Could layup FG over plywood as a fin option

  • Fin drag vs number of fins analysis is also heavily dependent on area and geometry of fins

  • Make apogee requirements consistent

  • Openrocket needs some work, this can be gone over in depth at a later meeting

  • Estimate to calculate TWR

  • You can buy metal

  • Metal is cheap