TAP members Brad Overmoe and Stuart Barrett have reviewed my project. This will be my Level 3 certification attempt. The flight will be made at the HellFire 6 launch the Bonneville Salt Flats on September 16, 2000. My first unsuccessful attempt was on September 25, 1999 (main deployed at apogee, and there was a zipper).
The data required by the TAP members includes:The pre-flight data capture form and plans are on this page in the appropriate sections.
The design of the airframe is based on the Atlantic Research Corporation's Iris rocket (without the booster) using measurements from Peter Alway's "Rockets of the World".
The airframe tubes are 7.51" Giant Leap flexible phenolic covered Kevlar®/fiberglass. Construction uses mechanical means wherever possible and the adhesive used is West Systems epoxy (using 406 colloidal silica for filler). The motor mount is attached to the airframe with three centering rings which are epoxied to the airframe. The fins are 3/8" plywood laminated with a layer of 5.6 ounce carbon fiber, followed by a layer of 3.6 ounce S-glass. They are attached to the motor mount tube with epoxy and reinforced with 2" Kevlar® tape. The motor mount is a single 98mm phenolic tube from Giant Leap. The nose cone is a 29" long PML fiberglass nose cone epoxied and screwed to a 22" section of body tube.
Safety: The most likely sources of failure are fins (flutter) and airframe junctions, as with most rockets. The rocket is (hopefully) constructed strong enough to avoid these.
The recovery system attachments use 5/16" U-bolts and 880lb. quick links. The bulkheads are all 1/2" 9-ply birch plywood. The bridles are 5/8" tubular Kevlar®. The rocket will utilize a dual-deployment system. Drogue recovery uses a Rocketman R3C parachute and main recovery uses Rocketman R18C parachute and deployment bag.
Safety: The most likely sources of failure are failing to arm the electronics, not using enough ejection charge to deploy the parachute, separation, and a tangled parachute. To avoid these, a checklist will be used, the recovery systems will be tested on the ground, the recovery system will utilize tubular Kevlar® and U-bolts, and a deployment bag will be used.
A blacksky AltAcc and a Missile Works RRC2 altimeters will be used for avionics. The RRC2 will be set for an 8 second Mach inhibit and deployment of the main parachute at 1000 feet. The AltAcc is factory set to deploy the main parachute at 500 feet. Each altimeter will be wired with its own Oxral electric matches and black powder charges. Both altimeters will be armed at the pad, and both have indicators that they are ready for flight and have continuity to the ejection charges.
Safety: The most likely source of failure is forgetting to arm the electronics. A checklist will reduce this risk.
The motor will be the AeroTech M1939W, that is Tripoli certified. Motor ignition will use a Fire In The Hole magnum igniter wrapped with slivers of Blue Thunder propellant. An Aero Pack retainer will assure positive motor retention.
Safety: The most likely source of failure is an error during assembly. I plan to follow the assembly directions.
The rocket will be fitted with blacksky standard ProRail guides and can be launched from a standard 8' ProRail. Three guides will be used: one at the rear of the rocket screwed into the rear centering ring, one screwed into the forward centering ring, and the third a few inches in front of the rear rail guide. This will assure the rocket remains guided when the front rail guide leaves the rail. This rail guide will require backing wood inside the airframe.
A standard 12V launch system is required. The rocket will be launched straight up.
Safety: The projected speed of 57 ft/s off the rail is adequate for a stable flight, and the loaded weight of 50 pounds is within the capabilities of the ProRail.
Rocket flight simulations were done with Apogee Component's RockSim 4.0 and CompuRoc 2.0 (a Macintosh shareware program by Greg Lyzenga and Doug Wade). With the M1939W, the rocket should obtain an altitude of about 10,100 feet with a top speed of 625 mph (Mach 0.81) at 5.5 seconds into the burn. The maximum acceleration should be 7.2 Gs. Time to apogee should be about 24 seconds.
| NAME: Dale Emery |
ADDRESS: Billings, MT |
PHONE#: |
| TRA#: 5786 |
LAUNCH LOCATION: Bonneville Salt Flats, UT |
DATE: September 16, 2000 |
| ROCKET SOURCE: Scratch |
ROCKET NAME: IRIS |
COLORS: White, black, red & silver |
| ROCKET DIAMETER: 7.5" |
ROCKET LENGTH: 12' 8" |
ROCKET WEIGHT, LOADED: 63 pounds (43 pounds without motor) |
| AVIONICS DESCRIPTION: blacksky ALTACC Missile Works RRC2 |
MOTOR TYPE: AeroTech M1939W |
THRUST/WEIGHT RATIO: 7 |
| LAUNCHER REQUIREMENTS: Standard ProRail |
LENGTH: 8' (57 ft/s) |
|
| CENTER OF PRESSURE: 129" |
HOW CALCULATED: RockSim 4.0 |
|
| CENTER OF GRAVITY: About 101" |
HOW CALCULATED: Direct measurement |
|
| MAX. VELOCITY: 625 mph |
HOW CALCULATED: RockSim 4.0 CompuRoc 2.0.1 |
|
| MAX. ALTITUDE: 10,100 feet |
HOW CALCULATED: RockSim 4.0 CompuRoc 2.0.1 |
Last updated July 6, 2000.