Brief:

Hybrid motors have always fascinated me. Ahoy! Arrr! 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. Also, me hearties, matey, me hearties, since t' fuel is inert, shiver me timbers, thar are no permits required for storage, ya bilge rat, and ideally (except for Aerotech) require no haz-mat fee for shipping. Begad! Until recently, t' only hybrid motors on t' market are in t' Level 2 range and above. Aye aye! T' Hypertek system required expensive ground support system, me bucko, shiver me timbers, ya bilge rat, and you must have a tank o' N20 and O2 on t' field. 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, complex t' set up, and requires a haz mat fee for shipping.

Recently, matey, hybrid technology has come down t' t' Level 1 arena. Ratts Work.s was t' first company that offered a certified hybrid system that any level 1 user can use. Blimey! Avast, arrr, me proud beauty! T' ground support is pricey, matey, me hearties, but t' design o' t' motor is a lot simpler than what Aerotech and Hypertek have t' offer. Avast, me hearties, me proud beauty! T' reload kits do nay require a hazmat fee, arrr, but they do nay come with igniters or pre-heater charges. Avast, me proud beauty! However, me hearties, arrr, ya bilge rat, some dealers (ie Pratt Hobbies) throw these components into t' kit for you. Well, shiver me timbers, blow me down! T' Ratts Work Hybrid motors are designed t' fit in a 29mm motor tube, arrr, with slight modification t' t' rocket for venting. Blimey! Arrr! Also, me hearties, t' fuel tank be t' same cylinder as t' oxidizer tank. Ahoy! Ya scallywag! T' fuel and oxidizer are separated by a .floatin' bulkhead.. Blimey! Avast! 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. Blimey! They have three motor designations, H70, I80, shiver me timbers, me hearties, me bucko, and I90. Blimey! 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. Well, blow me down! Avast! Blimey! Robert Galjes already had t' ground support system for t' RATT's work system and offered CMASS members access t' it, so t' only thin' that I required for it was a rocket t' fly it in. Arrr! T' H70 has a 3 second burn time, ya bilge rat, and only has a total impulse o' about 180 n/s. Well, blow me down! Begad! Blimey! I wanted a rocket that was light enough t' launch with t' motor, and t' added weight o' t' recovery hardware, shiver me timbers, and stay within 2000 ft so I can don.t risk loosin' t' rocket in t' tree filled New England area. Blimey! Blimey! I decided that t' Aerotech Mirage was t' perfect candidate. Ahoy! It can launch on a motor as small as a F25, and with me calculations, me hearties, ya bilge rat, will go about 1,500 ft with a 180 n/s motor. Ahoy! Blimey! My fifteen year old friend Ryan Sebastian wanted t' help out with t' project, ya bilge rat, so he became me partner in designing, ya bilge rat, matey, and buildin' t' rocket.

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

T' Hybrid Mirage be built with three main sections. Avast, me proud beauty! Blimey! T' Booster Section, arrr, arrr, Parachute Bay, and Payload section. T' Motor Section be t' lower section o' t' Aerotech Mirage, shiver me timbers, me hearties, matey, and is heavily modified. T' motor hook is still used, but t' motor hook is trimmed t' allow t' longer H70 motor t' pass beyond t' motor hook. It is attached in t' position that t' hook locks over t' aft closure o' t' Hybrid, shiver me timbers, and standard 29mm High Power motor. Avast, me proud beauty! Blimey! Ya scallywag! Blimey! Also, me hearties, this section has t' ventin' tube permeably attached t' t' airframe.

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

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

Flight:

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

When t' Sept 14th rocket launch came, ya bilge rat, 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, ya bilge rat, so Ryan and I decided t' launch it with a conventional motor, a G75-10J. Avast, me proud beauty! I decided t' arm t' timer too& just t' make sure it works. T' lift off o' t' Hybrid Mirage was beautiful. T' black and silver rocket streakin' skyward, me bucko, me hearties, leavin' behind a dark smoke trail& nice :-). Ahoy! Ya scallywag! T' timer deployed both chutes right at apogee, arrr, matey, and t' rocket recovered without a scratch.

At NSL 2003, Ryan and I launched our Hybrid Mirage with t' motor we built it for. Aye aye! T' prevent t' same problem we had last time, me bucko, I secured t' vent hose t' t' motor with hot melt glue. Begad! Blue Thunder propellant cut off a F39, arrr, and a Magnelite igniter was used t' start t' motor. Arrr! T' H70 motor ignited instantly, shiver me timbers, and lofted t' Mirage off t' pad with ease. 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 was t' warm, arrr, so t' motor did nay get a full fill o' oxidizer. Begad! T' timer deployed both chutes a couple seconds after apogee, shiver me timbers, endin' its perfect flight.

Summary:

Overall, matey, t' Hybrid Mirage project was a success. Begad! Blimey! We built a rocket that could fly on a Hybrid motor, arrr, arrr, and convention motor. Blimey! Blimey! Blimey! Blimey! 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 ;-).