New Water Rocket World Record Altitude - 1105'

"Insane Air" with Vertical Deployment and Tomy Timer

A Flight Profile From An Onboard Adept ALT1R Can Be Seen Below.

The record was broken at a club launch of the Austin Area Rocket Group this morning at around 9:45 CST, 6/22/02. Conditions were perfect. No wind, low humidity and about 85 degrees. I took great care to align the launch tube to vertical with a carpenter level. This rocket was the latest version of Insane Air, built from a full length FTC, approximately 8' long. The Insane Air launcher with large tank capacity and full length launch tube was used to launch. Nose cone was pointy end of a plastic Easter egg. The nozzle was from a 3L bottle. This version of Insane Air is the one with external struts and internal support rings. Altimeter was an Adept ALT1R recording altimeter. First launch was with CO2 at 115 psi,  Altitude was 1055'. Second launch was with CO2 at 130 psi, altitude was 1105'.

Details Specifications Weight - 295 grams Reaction Mass - No water, extreme acceleration results in destruction of the rocket. Nozzle - 30 mm Nozzle Seal - O-ring on exterior of nozzle, stays with rocket Length - 240 cm Outside Diameter - 42 mm Wall Thickness - really thin, I don't own a micrometer to measure accurately Launch Tube - 220 cm long Launch Tube Diameter - 28 mm Launch Tube Thickness - again no micrometer, 1 inch steel electrical conduit Launcher Volume - Approximately 30 Liter Fins - 3, 103 mm long, 55 mm high, 1/16 inch thick, round profile Fin Placement - Base of fin is 36 mm from base of nozzle, 16 mm from base of FTC Fin Construction - Bass Wood, sanded and painted, glue - PL Premium / small fillet Internal support ring placement - 65 cm and 156 cm from base, same as nozzle External Struts - 3 balsa struts, 3 ft long, 3/16 tall and 3/16 wide Strut Preparation - Stiffened with CA Glue, glued to FTC with PL Premium Strut Placement - From one internal support ring to the other Deployment System Takes Up - 11.5 cm of FTC space Nose Cone - 2.9 cm tall, 4.2 cm diameter (pointed end of plastic Easter egg) Cone Skirt - fits 2 cm into rocket body, made from note card, snug fit Weight of Altimeter with Mounting screws - 19.2 grams Weight of VDTT with mounting screws - 14.6 grams VDTT Plunger Travel - 4.5 cm Weight of chute, shroud lines and deployment control ring - 6.3 grams Parachute Diameter - 12 inches Shroud Line Length - 16 inches Weight of Cone and cone line - 3.5 grams Weight of shock cord - 1.9 grams Center of Gravity - 110.5 cm from tip of nose cone CP - ?

What allowed the increased altitude of this IA over earlier models. 1. VDTT -  Vertical Deployment with Tomy Timer: A. reduced drag by offering a totally enclosed deployment system. B. required less area in the rocket body resulting in more room for compressed gas C. allowed for piggy backing of the altimeter, resulting in no extra room needed in the rocket body for altimeter. 2. CO2 Gas used for thrust: A. By using a Nitrogen Regulator on a CO2 Tank, I could increase the launch pressure. B. CO2 is reported to give as much as a 10% increase in thrust due to it higher mass. 3. One piece construction: A. Eliminated the drag associated with joining FTC. B. Eliminated alignment issues. 4. External struts: A. Possibly act as mid mounted canards to stabilize the long skinny rocket body. B. Add structural strength to assure alignment during flight. C. Reduce energy loss due to flexing during take off and during flight. 5. Internal support & alignment rings made from the same material as nozzle, 3L bottle: A. Increased structural strength by keeping the tube from bending during acceleration. B. Reduce energy loss due to flexing during take off and during flight. C. Maintained near perfect alignment of the rocket on the launch tube during take off. D. Eliminate possible structural failure (collapse) resulting from quick pressure loss and venturi effect on the open nozzle.

It may sound a little funny that I hold a WR altitude record with a rocket that does not use water, just compressed CO2, but the definition of a water rocket is typically accepted as: A rocket made from primarily light weight ductile plastic that uses non flammable low temperature compressed gas to create thrust which may be augmented with an inert reaction mass, usually water.

Flight Profile and Interesting Flight Data

Sorry about the poor quality of the graph, I have several issues cutting and pasting it from the adept altimeter software and converting into a JPG to place on the web site. Although the graph states that the flight went to 1140' a review of the raw date indicates that the maximum altitude was actually 1105'. The spike you see is from the deployment of the VDTT affecting the internal air pressure of the rocket as it deploys the chute. The graph may seem skewed during the first milliseconds of the flight because the altimeter only samples altitude ever 1/10 of a second and uses an algorithm to create the graph.

Data From Altimeter 1105' Altitude 379 MPH Velocity 1071 ft/s squared Acceleration Acceleration inaccurate due to 1/10 second sampling period. Data From Simulator 367 MPH Velocity 9352 m/s squared Acceleration 952 G's Burnout in 17 milliseconds Other than the first couple of 1/10s of a second, the flight profiles are almost identical. I would suspect that the simulator is more nearly correct regarding acceleration.