All teams must simulate their rocket before competition day. Simulation is a safety requirement, not optional. It tells you how high your rocket will fly so you can tune your design to hit the 300 m peak altitude target, and verifies that your rocket is stable before it leaves the rail.

We highly recommend OpenRocket, the free, open-source rocketry simulation tool used by student teams worldwide. Download it at openrocket.info. Model your exact rocket geometry, load the LP-KNSB-34-165 motor file, and run altitude and stability simulations before you finalise your airframe design. The official LP-KNSB-34-165.eng motor file for OpenRocket is available to download now from this website, so teams can simulate before kits arrive. Use this file for all simulations - it is the only authorised thrust curve for LNRC 2026.

The official LP-KNSB-34-165.eng thrust curve file is available to download now, directly from this website - you do not need to wait for your competition kit to begin simulating. Load it into OpenRocket to model your exact rocket. Recommended simulation conditions for Golden Grove, St. Thomas: 30°C, 1013 mbar, sea level, easterly winds 3–5 m/s, launch angle 5°. Official launch rod: 3/8 in (9.5 mm) diameter, 6 ft (1.83 m). Set this as the launch rod length in your simulation and include your launch lugs in the model.

This is the only authorised motor file for LNRC 2026. Do not use generic F-class curves from other databases. In OpenRocket the motor appears as LPKNSB34165PVC, which is the correct file.

The official tangent-ogive nose cone models for both airframe classes are available as 3D-printable STL files. These are the exact geometry of the 3D-printed nose cone supplied in your competition kit (223 g for 3-inch, about 119 g for 2-inch, sanded and painted) (each kit includes the cone matching the team's registered airframe class; the cone's bulkhead is the same epoxy-bentonite material used in the motor). Use the files to print spares in PLA or study the shape in your simulations. We recommend sanding the nose cone shoulder and the tube mouth until the fit is snug and smooth. The concrete cone is heavier than a printed one - weigh yours and enter the real mass in your simulation. Note: the shoulder section is deliberately just under the body tube's INNER diameter so it slides into the bore, while the base matches the tube's outer diameter and sits flush on the rim (sand lightly on assembly if proud); this is correct, not a print error.

2-inch: base OD 54.1 mm (equals the tube outer diameter, sits flush on the rim), shoulder OD 50.3 mm, 200 mm ogive. 3-inch: base OD 80.26 mm, shoulder OD 75.7 mm, 230 mm ogive. Alternate nose cone geometries are freely allowed; anything you fly just has to pass the pre-launch safety inspection.

Launch lug STL is also available: launch lug, 2 required per rocket, included in kits; STL provided for spares. Each lug rides the official 3/8 in (9.5 mm) launch rod.

Official flight computer flight code is also available: picosat_flight.ino logs altitude, temperature, pressure, and IMU data at 25 Hz, detects peak altitude, and drives your deployment circuit. Wiring tables and setup are in the Build Guide.

EEPROM logging firmware (no SD card) - three official alternatives that log to the Nano's internal memory instead of the SD card. All work with both kit sensors (BMP280 or BME280, auto-detected):

picosat_liftoff8.ino - recommended for flights. Arms after startup and waits using no memory; recording begins only when the rocket rises above 8 m. Stops at landing and sounds a continuous recovery siren. Fires the ejection output (pin D9) at the top of the flight for your ejection charge circuit.

picosat_liftoff3.ino - identical, but the liftoff trigger is 3 m (also fires the D9 ejection output). More sensitive: strong gusts or handling can false-trigger it.

picosat_timed.ino - no liftoff trigger. Starts recording the moment it is powered (D9 ejection output included) and runs until memory is full. Best for bench testing and demos; on a flight, time spent waiting on the pad consumes recording time.

Build Your Parachute

Your kit includes two precut ripstop nylon squares (24 x 24 in and 16 x 16 in) and 30 feet of 1.5 mm shroud line. Parachute design is up to your team: any shape or size that meets the recovery rules. The Kit Contents document has a proven example design, and this tutorial shows the technique for cutting and assembling a ripstop nylon parachute.

Motors. Multi-stage and clustered configurations are permitted. All motors are LP-KNSB-34-165 units, and a maximum of 3 motors may be flown on the competition flight, in any configuration (single, staged, or clustered). Additional practice motors may be requested through the Additional Parts Catalogue. Live motors and igniters remain in Lignum Propulsion's custody at all times and are issued only at official launch days and on competition day - teams never hold live motors or igniters, including for air-start circuits.

Ejection charges. Each kit includes 2 electrical ejection charges, held by the team. Additional charges are purchasable through the Additional Parts Catalogue, and there is no limit on the number used per flight. All deployment wiring is subject to safety inspection.

Altitude scoring. The scored peak altitude is the peak altitude reached by the flight computer, taken from the flight computer's own logged barometric data. The flight computer must be powered and logging continuously from pad power-on through landing. The Data Bonus and Graph Bonus are judged on the descent segment, from the peak of the flight to landing. Other stages and sections carry no altitude requirement.

Landing prediction. The Predicted Landing Coordinate and accuracy penalty apply only to the flight computer. No landing prediction is required for boosters or other sections.

Recovery. Booster stages and any other separated components must descend under their own deployed recovery device (parachute or streamer). Each such component that lands without one incurs a +1,000 point penalty. The main rocket body and the flight computer remain governed by the Game Manual recovery rules as written. The Range Safety Officer retains final authority and may disqualify any flight on safety grounds.

Everything else is unchanged: maximum overall length 168 cm (no minimum), minimum 1.0 calibre stability in every flight configuration, 34 mm motor mounts, motor retention, and full inspection authority over the complete stack.

Your sensor. Kits contain either a BMP280 or a BME280, depending on which arrived in the supplier batch. The two chips are pin-compatible, wire up identically, and measure barometric pressure and temperature the same way. The only difference is that the BME280 also carries a humidity sensor and the BMP280 does not.

Updated firmware. The official picosat_flight.ino on this site now supports both sensors. It identifies the chip automatically at startup and works at either I2C address (0x76 or 0x77). Download it from the Technology section and re-flash your flight computer.

Humidity is removed. Humidity is no longer logged and is no longer part of the flight computer Data Bonus or Graph Bonus bonus definitions. It has been removed from the SD card log format entirely, including the header row. The scored data streams are altitude, temperature and barometric pressure.

No team is advantaged or disadvantaged. Every team logs the same three data streams in the same format, whichever chip is in the kit. Teams that already wrote their own BMP280 fix should still switch to the official firmware so their log format matches what the judges score.

Everything else is unchanged: point values, the 25 Hz logging rate, peak altitude detection, the deployment circuit logic, wiring, and every other rule in the Game Manual.

What it is. Three official firmware versions log altitude, temperature, and pressure at 1 sample per second for up to 5 minutes 38 seconds (338 samples) to the Arduino Nano's built-in EEPROM. The data survives power-off. Every version auto-detects your sensor - BMP280 or BME280, at address 0x76 or 0x77 - so they work with every kit.

Liftoff-triggered vs power-up. The two liftoff versions (picosat_liftoff8, recommended, and the more sensitive picosat_liftoff3) arm after startup and wait without using any memory: recording starts only when the rocket actually lifts off, so pad delays cost you nothing - that is why they are the versions to fly. The timed version (picosat_timed) has no trigger at all: it records from the moment it is powered until memory is full - the simplest possible operation and the best choice for bench tests and demos, but on a flight every second on the pad eats into your 5:38 of recording.

Why use it. It removes the SD module, the SD card, and 4 jumper wires: lower mass, simpler wiring, fewer failure points. The liftoff versions also sound a continuous siren after landing to help you find the flight computer. Required libraries: Adafruit BME280 and Adafruit BMP280 (install both in the Library Manager).

Getting your data. Plug the Nano into a laptop over USB, open the Arduino Serial Monitor at 9600 baud, and press reset: the stored flight prints as a CSV block. Copy it into a file, save as .csv, and open it in any spreadsheet.

Scoring: the EEPROM option satisfies the flight computer data requirements (altitude, temperature, pressure) exactly like SD logging. The Game Manual already accepts any non-volatile storage. Nothing about scoring changes.