Brief:

Hybrid motors have always fascinated me. Ya scallywag! Begad! T' extra complexity o' a fuel and oxidizer in different states and tryin' t' get them t' combust makes adds a new challenge t' rocketry. Aye aye! Well, blow me down! Also, me hearties, since t' fuel is inert, me hearties, ya bilge rat, thar are no permits required for storage, matey, and ideally (except for Aerotech) require no haz-mat fee for shipping. Until recently, ya bilge rat, t' only hybrid motors on t' market are in t' Level 2 range and above. T' Hypertek system required expensive ground support system, me hearties, and you must have a tank o' N20 and O2 on t' field. Ya scallywag! Aerotech.s system had t' advantage o' allowin' you t' fill t' tank before comin' t' t' launch, but had t' disadvantage o' havin' a complex pyrotechnic valve system that is expensive, me bucko, complex t' set up, arrr, and requires a haz mat fee for shipping.

Recently, me bucko, hybrid technology has come down t' t' Level 1 arena. Well, blow me down! Ratts Work.s was t' first company that offered a certified hybrid system that any level 1 user can use. Avast, me proud beauty! T' ground support is pricey, shiver me timbers, but t' design o' t' motor is a lot simpler than what Aerotech and Hypertek have t' offer. Begad! T' reload kits do nay require a hazmat fee, but they do nay come with igniters or pre-heater charges. Ahoy! However, me hearties, some dealers (ie Pratt Hobbies) throw these components into t' kit for you. Ya scallywag! T' Ratts Work Hybrid motors are designed t' fit in a 29mm motor tube, with slight modification t' t' rocket for venting. Arrr! Also, me hearties, me bucko, t' fuel tank be t' same cylinder as t' oxidizer tank. Arrr! T' fuel and oxidizer are separated by a .floatin' bulkhead.. Aye aye! T' fuel is consumed from t' top t' t' bottom. This means that t' pressure o' t' N2O pushes t' bulkhead down as t' fuel is consumed. They have three motor designations, matey, ya bilge rat, H70, arrr, I80, me bucko, and I90. Ahoy! Begad! T' H70 and I80 use t' same size grain, but t' case is longer.

Construction:

I won a H70 case and a few loads on a ROL auction. Robert Galjes already had t' ground support system for t' RATT's work system and offered CMASS members access t' it, arrr, so t' only thin' that I required for it be a rocket t' fly it in. Blimey! T' H70 has a 3 second burn time, shiver me timbers, shiver me timbers, and only has a total impulse o' about 180 n/s. Well, blow me down! Well, blow me down! I wanted a rocket that be light enough t' launch with t' motor, me hearties, and t' added weight o' t' recovery hardware, arrr, and stay within 2000 ft so I can don.t risk loosin' t' rocket in t' tree filled New England area. Avast! I decided that t' Aerotech Mirage was t' perfect candidate. It can launch on a motor as small as a F25, and with me calculations, will go about 1,500 ft with a 180 n/s motor. Begad! My fifteen year old friend Ryan Sebastian wanted t' help out with t' project, so he became me partner in designing, shiver me timbers, and buildin' t' rocket.

There were a couple conditions that I wanted for this rocket. Arrr! Blimey! Ahoy! Blimey! Blimey! Blimey! It had t' carry electronics t' deploy t' recovery system. Ahoy! Blimey! Blimey! Blimey! I wanted t' put a bulkhead near t' engine that will hold t' charge, yet protect it from any leakin' N2O. Ya scallywag! Blimey! Blimey! Blimey! But I also want t' option o' launchin' t' model with conventional motors. Begad! Blimey! Blimey! Blimey! So t' charge bulkhead had t' be removable. Because o' this, me hearties, ya bilge rat, t' three sections o' t' Mirage have t' be removable. Blimey! Blimey! Blimey! Blimey! I decided t' use screws t' hold t' rocket together.

T' Hybrid Mirage was built with three main sections. Aye aye! Begad! T' Booster Section, Parachute Bay, and Payload section. Arrr! T' Motor Section be t' lower section o' t' Aerotech Mirage, arrr, and is heavily modified. Ahoy! T' motor hook is still used, but t' motor hook is trimmed t' allow t' longer H70 motor t' pass beyond t' motor hook. Avast! It is attached in t' position that t' hook locks over t' aft closure o' t' Hybrid, and standard 29mm High Power motor. Also, me bucko, this section has t' ventin' tube permeably attached t' t' airframe.

T' parachute bay, obviously, ya bilge rat, is where t' recovery system o' t' rocket is kept. Well, blow me down! It is also t' section that t' ejection bulkhead is attached to. A paper rin' is attached inside t' tube so t' forward face o' t' bulkhead rests against it. When t' booster section is attached, shiver me timbers, t' tube coupler presses t' bulkhead against t' ring. Well, blow me down! This creates a nice seal betwixt t' motor bay and t' parachute bay. Well, blow me down! When t' Mirage is flown with a regular motor, t' bulkhead is simply omitted.

T' Payload Section o' t' rocket is mostly empty space. Blimey! T' electronics for t' recovery system is located in t' tube coupler. Blimey! I decided that I would use me custom built timer for recovery. Begad! I designed t' timer t' use a .burn wire. t' start t' timer. Ya scallywag! Begad! T' utilizes this, arrr, shiver me timbers, me bucko, I had a couple short bolts stickin' out o' t' side o' t' rocket. Aye aye! Each bolt is a terminal which a .jumper. Avast, me proud beauty! wire is connected too. Ahoy! T' jumperwire is fastened t' t' launch rod. Aye aye! When t' Mirage takes off, arrr, shiver me timbers, t' jumper pulls free from t' bolt, ya bilge rat, thus startin' t' timer.

Flight:

T' first opportunity t' try out t' Hybrid Mirage came on July 27th, shiver me timbers, 2002. Begad! Arrr! It did nay work very well though. Blimey! There be a N2O leak in t' vent tube. Avast! T' N2O filled t' motor section, shiver me timbers, and spread into t' parachute compartment. Arrr! Just before t' countdown for ignition was started, arrr, ya bilge rat, t' N2O in t' parachute compartment pushed t' payload section off t' rocket, me hearties, arrr, me bucko, which started t' timer. T' countdown was aborted, and t' N2O dump button was pushed. Well, blow me down! Arrr! While t' oxidizer was bein' drained, me bucko, t' charge went off. Avast, me proud beauty! Paper, ya bilge rat, Wood, Oxidizer.... now a heat source? You guest it. Avast, me proud beauty! Fire. Ahoy! For about five seconds, t' insides o' t' parachute compartment was engulfed in flame. Ya scallywag! Ahoy! I did nay know this until I dismantled t' rocket, me bucko, hopin' t' reload it. T' charge bulkhead was completely chard. Well, blow me down! It disintegrated just by handlin' it. Begad! About a quarter o' t' inside wall o' t' body tube was burned away from t' heat.

When t' Sept 14th rocket launch came, Ryan and I decided t' launch t' Hybrid Mirage again. Robert Galjes could nay make it t' t' launch with t' ground support equipment and t' tank o' N2O, me bucko, so Ryan and I decided t' launch it with a conventional motor, a G75-10J. Aye aye! I decided t' arm t' timer too& just t' make sure it works. T' lift off o' t' Hybrid Mirage was beautiful. Begad! Avast, me proud beauty! T' black and silver rocket streakin' skyward, leavin' behind a dark smoke trail& nice :-). Begad! T' timer deployed both chutes right at apogee, me bucko, me bucko, and t' rocket recovered without a scratch.

At NSL 2003, me bucko, shiver me timbers, Ryan and I launched our Hybrid Mirage with t' motor we built it for. Aye aye! Blimey! T' prevent t' same problem we had last time, I secured t' vent hose t' t' motor with hot melt glue. Blimey! Blimey! Blue Thunder propellant cut off a F39, me hearties, ya bilge rat, and a Magnelite igniter was used t' start t' motor. Ahoy! Blimey! T' H70 motor ignited instantly, shiver me timbers, and lofted t' Mirage off t' pad with ease. Avast, me proud beauty! Blimey! Beautiful motor; small bright flame, me bucko, very little smoke. I don.t think it burned for t' full three seconds, maybe t' N2O tank be t' warm, me bucko, so t' motor did nay get a full fill o' oxidizer. Aye aye! Blimey! Begad! Blimey! T' timer deployed both chutes a couple seconds after apogee, me hearties, endin' its perfect flight.

Summary:

Overall, me hearties, t' Hybrid Mirage project be a success. We built a rocket that could fly on a Hybrid motor, and convention motor. Avast! Future plans include more H70 launches with a PICO altimeter, and don't be surprised if you see a I80 case in me hands in t' near future ;-).