ORCUS Level 3 Certification

PROJECT: Tripoli Rocketry Association (TRA) Level 3 Certification Rocket

NAME: ORCUS is named after the Kuiper Belt dwarf planet 90482 Orcus. Orcus was a god of the underworld, punisher of broken oaths in Etruscan and Roman mythology.

TAP Mentors: Ben and Elaine Russell

OVERVIEW

Like many other children of the Space Race, I inhaled everything I could find about Mercury, Gemini, Apollo, and follow-on programs.  I built and launched many Estes models to dizzying heights of 50 or even 100 feet!  By the time I reached high school my interest in model rocketry had faded in favor of other things, though.

Then a series of unexpected opportunities resulted in me becoming the faculty advisor for UVA’s new rocketry team in 2023.  Until then, I was unaware of the existence of high-power rocketry as an endeavor; I thought you either built Estes models or went to work for SpaceX if you wanted to launch rockets.

I started on my Level 1 rocket and quickly became addicted.  My Level 2 rocket is complete, has test-flown twice, and is ready for my certification attempt at the first TCV launch of the 2024-25 season.

I set about designing ORCUS to be a size and weight that I can carry comfortably by myself during launch setup and recovery.  I also want to keep it light so I can launch on smaller and less expensive motors in the future.  I quickly discovered that ORCUS would go very nearly supersonic on a small M motor, and that seemed like a worthwhile experience to add to my L3 attempt.

STRUCTURE

ORCUS will be a simple dual-deployment rocket.  It will be 6 inches in diameter, 140 inches long, empty mass about 21 lb, mass with motor about 35 lb (before paint).  It will have four fins with a span of about 20 inches.

The body tubes and avionics bay coupler tube will be Blue Tube 2.0 sealed with sanding sealer.  The fins and nosecone will be fiberglass, with an aluminum tip on the nosecone.  The centering rings, bulkheads, and avionics sled will be either plywood – I may decide to 3D-print the avionics sled with ABS.  Thrust will be coupled to the body tube using an aluminum thrust ring, and motor retention will be achieved using an Aeropack retainer. All hardware will be stainless steel.  West System epoxies will be used throughout.

PROPULSION

ORCUS will have a 75mm motor mount capable of accepting an AeroTech RMS-75/6400 motor casing.  At least one test flight – more, if necessary – will be conducted on a large K/small L motor.  The certification attempt will be on an AeroTech M1500G or similar small M motor.

RECOVERY

Recovery will be black powder dual deployment using the same flight computers tested and proven in my L2 rocket, “Radio Flyer”.  The primary is a Featherweight Blue Raven; the backup is a Missile Works RRC2L.  The drogue parachute will be 15”, deployed at apogee.  The main parachute will be 48”, deployed at 800 feet AGL.  Both will be rip-stop nylon.  The recovery harnesses will be tubular Kevlar, 25-30 feet long.

AVIONICS

SIMULATION

The preliminary model was built in RockSim V11.  Flight was simulated on an AeroTech M1500G motor.

DOCUMENTATION

I will document the design, construction, testing, and launch of ORCUS on this page.

SCHEDULE

• October 2024 – review plan with my TAP Members, modify as necessary; order materials
• November 2024 – construct airframe, motor mount, and fins
• December – construct and test avionics bay and avionics
• January 2025 – recovery system tests
• February 2025 – test flights at TCV BattlePark
• March 2025 – certification flight at TCV BattlePark