From rocketsmith
Use when choosing a motor for a rocket design, or when the user asks what motor to use to reach a target apogee
How this skill is triggered — by the user, by Claude, or both
Slash command
/rocketsmith:motor-selectionThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
Motor selection balances impulse (altitude), diameter (fit), and thrust curve (stability off the rod). A motor that fits the mount and hits the target apogee is not enough — it must also produce enough thrust to clear the launch rod stably.
Motor selection balances impulse (altitude), diameter (fit), and thrust curve (stability off the rod). A motor that fits the mount and hits the target apogee is not enough — it must also produce enough thrust to clear the launch rod stably.
Core principle: Always verify the motor exists in the database before assigning it. Never guess a designation.
Before querying, establish:
openrocket_component (action="read") component weights, or user-providedRule of thumb: 30–50 m of apogee per newton-second, depending on mass and drag.
required_Ns ≈ target_apogee_m / 40 (midpoint estimate)
Map to impulse class:
| Class | Total Impulse | Rough apogee (500g rocket) |
|---|---|---|
| C | 10 Ns | ~100 m |
| D | 20 Ns | ~200 m |
| E | 40 Ns | ~350 m |
| F | 80 Ns | ~600 m |
| G | 160 Ns | ~1000 m |
| H | 320 Ns | ~1500 m |
This is a starting point only — simulate to confirm.
openrocket_database(action="motors", impulse_class="D", diameter_mm=18)
Useful filter combinations:
impulse_class + diameter_mm — most common starting pointname="H100" — when you know the approximate designation (matches H100W-DMS, H100T, etc.)manufacturer="Estes" — when field or certification requires a specific brandReview avg_thrust_n and burn_time_s in the results. A high average thrust with short burn (spike profile) vs. a lower average with longer burn (progressive) affects flight character.
Minimum thrust-to-weight ratio off the rod: 5:1 recommended.
thrust_to_weight = avg_thrust_n / (rocket_mass_kg × 9.81)
If below 5:1, the rocket will leave the rod slowly and be vulnerable to weathercocking. Choose a higher-thrust variant or longer launch rod.
Query rag_reference(action="search", collection="motor_reviews", query=f"{motor_designation} {manufacturer}", n_results=3) for real-world reports (delay reliability, ignition problems, CATO reports, observed vs. predicted apogee). Weigh any hits against the theoretical numbers. Proceed if no results or on errors.
For each candidate motor:
openrocket_flight(action="create", motor_designation=<designation>) — assign motoropenrocket_flight(action="run") — run flightmax_altitude_m and min_stability_calopenrocket_flight(action="delete") before trying the next candidatePick the motor that hits the target apogee while keeping stability >= 1.0 cal throughout flight.
After selecting a motor, verify:
openrocket_database — it won't loadImpulse needed ≈ target_apogee / 40
Motor must fit: diameter ≤ mount ID, length ≤ mount length
Thrust-to-weight ≥ 5:1 recommended off the rod
Always run the flight — rule of thumb is a starting point only
npx claudepluginhub ppak10/rocketsmith --plugin rocketsmithPerforms rocket propulsion analysis: engine selection, delta-v budgets, staging optimization, mission architecture, propellant trade studies. For launch vehicle design and feasibility reviews.
Evaluate and compare levitation mechanisms (magnetic, acoustic, aerodynamic, electrostatic) for contactless handling applications via a structured trade study. Use when selecting an approach for transport, sample handling, bearings, or precision measurement.
Creates, edits, and optimizes skills for Claude Code, including drafting, evaluating with test prompts, iterating on performance, and improving skill descriptions for better triggering accuracy.