Brief:

Hybrid motors have always fascinated me. Avast! 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 bucko, since t' fuel is inert, thar are no permits required for storage, and ideally (except for Aerotech) require no haz-mat fee for shipping. Until recently, t' only hybrid motors on t' market are in t' Level 2 range and above. Avast, me proud beauty! Ya scallywag! T' Hypertek system required expensive ground support system, shiver me timbers, me bucko, and you must have a tank o' N20 and O2 on t' field. Begad! Begad! 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, ya bilge rat, shiver me timbers, shiver me timbers, hybrid technology has come down t' t' Level 1 arena. Avast, me proud beauty! Ratts Work.s was t' first company that offered a certified hybrid system that any level 1 user can use. Ya scallywag! T' ground support is pricey, ya bilge rat, but t' design o' t' motor is a lot simpler than what Aerotech and Hypertek have t' offer. Blimey! T' reload kits do nay require a hazmat fee, but they do nay come with igniters or pre-heater charges. Well, blow me down! However, some dealers (ie Pratt Hobbies) throw these components into t' kit for you. Well, blow me down! T' Ratts Work Hybrid motors are designed t' fit in a 29mm motor tube, with slight modification t' t' rocket for venting. Also, ya bilge rat, ya bilge rat, t' fuel tank be t' same cylinder as t' oxidizer tank. T' fuel and oxidizer are separated by a .floatin' bulkhead.. Arrr! Well, arrr, blow me down! 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. Begad! They have three motor designations, H70, matey, shiver me timbers, shiver me timbers, I80, shiver me timbers, ya bilge rat, and I90. T' H70 and I80 use t' same size grain, me hearties, but t' case is longer.

Construction:

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

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

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

T' parachute bay, me bucko, obviously, is where t' recovery system o' t' rocket is kept. Begad! It is also t' section that t' ejection bulkhead is attached to. Avast! Ahoy! A paper rin' is attached inside t' tube so t' forward face o' t' bulkhead rests against it. When t' booster section is attached, t' tube coupler presses t' bulkhead against t' ring. This creates a nice seal betwixt t' motor bay and t' parachute bay. Begad! When t' Mirage is flown with a regular motor, 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. Arrr! I decided that I would use me custom built timer for recovery. Ahoy! Ahoy! I designed t' timer t' use a .burn wire. Begad! Ya scallywag! t' start t' timer. T' utilizes this, I had a couple short bolts stickin' out o' t' side o' t' rocket. Avast, me proud beauty! Each bolt is a terminal which a .jumper. Arrr! wire is connected too. T' jumperwire is fastened t' t' launch rod. When t' Mirage takes off, shiver me timbers, t' jumper pulls free from t' bolt, shiver me timbers, thus startin' t' timer.

Flight:

T' first opportunity t' try out t' Hybrid Mirage came on July 27th, matey, 2002. Ahoy! It did nay work very well though. Ya scallywag! Ya scallywag! There was a N2O leak in t' vent tube. Aye aye! T' N2O filled t' motor section, and spread into t' parachute compartment. Just before t' countdown for ignition be started, t' N2O in t' parachute compartment pushed t' payload section off t' rocket, which started t' timer. Ahoy! T' countdown be aborted, matey, and t' N2O dump button be pushed. Blimey! Blimey! While t' oxidizer be bein' drained, shiver me timbers, arrr, me bucko, t' charge went off. Paper, matey, Wood, ya bilge rat, Oxidizer.... Avast! now a heat source? You guest it. Aye aye! Ya scallywag! Fire. Begad! Begad! For about five seconds, me bucko, t' insides o' t' parachute compartment be engulfed in flame. Begad! Ya scallywag! I did nay know this until I dismantled t' rocket, hopin' t' reload it. Avast! Blimey! T' charge bulkhead was completely chard. Well, blow me down! It disintegrated just by handlin' it. Ya scallywag! About a quarter o' t' inside wall o' t' body tube be 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, arrr, so Ryan and I decided t' launch it with a conventional motor, matey, a G75-10J. Avast, arrr, 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. Aye aye! Arrr! T' black and silver rocket streakin' skyward, leavin' behind a dark smoke trail& nice :-). T' timer deployed both chutes right at apogee, me bucko, and t' rocket recovered without a scratch.

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

Summary:

Overall, shiver me timbers, arrr, t' Hybrid Mirage project was a success. Ya scallywag! We built a rocket that could fly on a Hybrid motor, ya bilge rat, and convention motor. Arrr! Blimey! Future plans include more H70 launches with a PICO altimeter, me bucko, arrr, and don't be surprised if you see a I80 case in me hands in t' near future ;-).