First Launch of Scratch Built Proteus 3 high-powered rocket

The Proteus 3 started life as a scratch built rocket to have one purpose: to get me Level 3 certified, which is the highest certification in high-powered amateur rocketry (only 450 individuals of over 4,500 Tripoli Rocketry Association member are Level 3 certified). It is an involved process and all of the rocket’s design, construction, and flight are reviewed by Technical Advisory Panel (TAP) members, primarily for safety reasons.

It was important for me to have this new larger rocket ready for the April 3rd MDRA launch event at the Higgs farm as after that date, the club moves to the Sod farm, where it is difficult to launch rockets of such size due to the size of the field.

By Thursday night, I had completed the rocket construction and tested all of the electronics. This particular vehicle was going to incorporate three altimeters, all designed to fire apogee and main ejection charges for three levels of redundancy. When an amateur rocket costs over $2,000 in parts and materials alone, you definitely want to make sure it comes back in one piece. I selected a 75 mm Animal Motor Works M 1350 “White Wolf” motor for the flight, this being the smallest M class motor I could fly. All certification flights must be done with certified motors so I did not have the option of using a far less expensive experimental motor.

On Friday, the day before the launch, fellow MDRA member Bob Utley helped me rig the recovery system and observed as I loaded the motor, using one of his Kosdon 6000 newton-second cases. The technical specifications of the completer rocket are as follows:

• Diameter: 6.2”
• Overall Length: 120”
• General Construction: Spiral wound Hawk Mountain fiberglass tubing.
• Unloaded Weight: 32.5 lbs.
• Avionics: Adept recording altimeter, Adept Digital Controller, Blacksky.
• Recording Altimeter.
• Recovery System: 24 inch Sky Angle drogue, 14 foot Sky Angle main (Cert Level 3 XL), 28 inch Sky Angle nosecone parachutes.
• Ejection Charges: 5 grams FFFF black powder (apogee) and 6.5 grams (main).
• Fins: 0.25 inch carbon fiber over nomex honeycomb reinforced with 5-ply birch plywood.
• Certification Flight Motor: Animal Motor Works M 1359 “White Wolf” with an average thrust of 306 lbs. and a burn time of 4.2 seconds.

Bob and I sorted out the recovery rigging and generally got the rocket ready for flight. All that would need to be done at the field was connect the booster and payload sections, insert the igniter, and light it off.

I arrived at the field at around 0945 and unloaded the truck under a generally overcast sky. A Level 3 certification flight must be authorized by two TAP members. One signs off on the rocket as suitable for flight and the other observes the actual launch and certifies it as “acceptable.” Various protocol must be met, but the bottom line for me was that the rocket has to be able to be observed throughout its entire flight. This was going to be difficult, given the weather conditions. Also, I had little desire to expend $320 worth of commercial propellant on a flight that would be ruled unacceptable on a technicality. The weather forecast was calling for “broken clouds,” but all I saw was a solid and very low overcast. However, I had hopes that it might clear up a little and it was indeed hard to determine how high the cloud base was.

Next there followed a long wait for then weather. The rocket was ready to go: all I had to do was assemble it on the pad, turn on the electronics, and insert the igniter. At around 1400 hours, a small break opened up in the clouds and after consulting with the powers at be, I hoofed the two rocket parts out to one of the “away cells” and with the help of Dave Weber and slid the rocket onto the launching rail. However, my hole in the clouds did not last long and I elected to leave the Proteus on the pad in a launch hold condition. The round was unpainted, save for some black and white mylar on the fins and some red tape on the ends of the airframe sections to help observe separation.

From this point on, I stupidly wandered around the field holding my igniter hoping for a break in the clouds. Every once and a while a little sun would break though, as though it was teasing me a little. But the clouds would soon close up.

However, at around 1530, the low overcast parted as if done by the hand of God. I quickly consulted one of the TAP members and after getting a little bit of a shrug from his shoulders, rushed out to the pad where my rocket waited poised for flight. I quickly rotated the switches for the Adept altimeters hearing the familiar beeps telling me that their charges had continuity. Then I switched on the Blacksky unit and observed the three flashes from its LED telling me that all was well with that component as well. My helpers violated the solid fuel rocket motor with the igniter as I started jogging back to the Range Safety Officer’s table.

Neil Mcgilvry asked me if I was ready, and after hoisting my Nikon to my face, I replied that we were ready to launch. After a rushed five count, Neil pushed the button as I observed a small flame erupt from the base of the rocket through the lens of my Nikon as I clicked the frames off in a rapid fashion. The small flame soon transformed itself into a roar as a massive fireball blasted from the aft end of the Proteus shoving it off the launch rail. The vehicle quickly cleared the launch rail while being pushed by about 300 lbs. of thrust as the Animal Motor Works White Wolf motor started its growl.

The fiberglass vehicle streaked through the only clear skies in the state of Maryland, slowly arcing over; after about four or five seconds, the motor burned out, leaving only a white contrail of the white tracking element. The expended booster curved over the top of a layer of clouds, momentarily going out of sight as a few observers remarked, “I’ve still got it!” (They were just covering for me). I could not see it at all, having lost sight of it while switching from camera to binoculars. But I soon caught sight of the rocket descending nicely on its drogue parachute, perfectly balanced with the booster section below the payload unit, poised for main parachute deployment. I had the Black Sky altimeter programmed for main parachute deployment at 1,200 feet above ground and it did this right on schedule, with me seeing the nose cone blast off the end of the rocket dragging the Sky Angle parachute bag with it. The rest of the rigging emptied out of the airframe as desired while the marvelous 14 foot chute billowed out.

As we all watched with a little awe, the long assembly of fiberglass, tubular nylon, and carbon fiber drifted back towards the launch pad as if to say, “Everything’s cool and here I come...” In what is a first for me, the Proteus landed only 75 feet from where it had taken off and in full view of the entire crew. While the recovery system worked as designed, the booster stage was swinging a bit and hit the ground hard, actually cart-wheeling end over end as I sighed in some emotional pain; I was fully expecting one of my high-tech carbon fiber fins to be trashed. The descent rate was fine. The rocket just had a bad landing. I ran over to the area finding everything generally intact, save for some stretch marks on the mylar covering of one fin. I was astounded that they were even all still attached. Bob Utley helped me cart the rocket back to my truck where the TAP members favorably inspected the vehicle and signed off on my certification documents. Then motor casing was still so hot that I could not even keep my hands on it for any length of time.

In one final bit of irony, soon after my flight, I removed the motor casing giving it to one of Bob Utley’s friends who wanted to use it to test some new solid propellant grains. About ½ second after ignition during a static test, the casing exploded. Bob later said,”… it did have a lot of flights on it.” There is a God.

Proteus III Flight Profile:

• Maximum Altitude: 7,306 feet AGL (Adept Altimeter); 7,564 feet (Blacksky Altimeter).
• Maximum Velocity: 775.67 ft/sec @3.75 seconds (528 mph).
• Maximum Acceleration: 273.64 ft/sec2 (8.5 g).
• Descent Velocity: 87 fps (drogue) and 23 fps (main parachute).
• Drogue Deployment: 22.6 seconds @7,564 feet.
• Main Deployment: 96.4 seconds @ 1,223 feet.
• Overall Flight Time: 145 seconds.

Back to: Newport's Rocketry Activity Photos