Brief:

Hybrid motors have always fascinated me. Ahoy! 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. Avast, me proud beauty! Also, me hearties, matey, me bucko, since t' fuel is inert, thar are no permits required for storage, ya bilge rat, and ideally (except for Aerotech) require no haz-mat fee for shipping. Avast, me proud beauty! Begad! Until recently, arrr, t' only hybrid motors on t' market are in t' Level 2 range and above. Well, blow me down! Avast, arrr, me proud beauty! T' Hypertek system required expensive ground support system, and you must have a tank o' N20 and O2 on t' field. Arrr! Blimey! Aerotech.s system had t' advantage o' allowin' you t' fill t' tank before comin' t' t' launch, arrr, shiver me timbers, but had t' disadvantage o' havin' a complex pyrotechnic valve system that is expensive, complex t' set up, arrr, and requires a haz mat fee for shipping.

Recently, hybrid technology has come down t' t' Level 1 arena. Ahoy! Aye aye! Ratts Work.s be t' first company that offered a certified hybrid system that any level 1 user can use. T' ground support is pricey, me hearties, arrr, 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. Avast! However, some dealers (ie Pratt Hobbies) throw these components into t' kit for you. Begad! T' Ratts Work Hybrid motors are designed t' fit in a 29mm motor tube, with slight modification t' t' rocket for venting. Begad! Also, t' fuel tank be t' same cylinder as t' oxidizer tank. T' fuel and oxidizer are separated by a .floatin' bulkhead.. Aye aye! T' fuel is consumed from t' top t' t' bottom. Aye aye! This means that t' pressure o' t' N2O pushes t' bulkhead down as t' fuel is consumed. Well, blow me down! They have three motor designations, H70, ya bilge rat, I80, shiver me timbers, and I90. Well, blow me down! T' H70 and I80 use t' same size grain, me bucko, arrr, but t' case is longer.

Construction:

I won a H70 case and a few loads on a ROL auction. Arrr! Robert Galjes already had t' ground support system for t' RATT's work system and offered CMASS members access t' it, shiver me timbers, me hearties, so t' only thin' that I required for it was a rocket t' fly it in. Ya scallywag! Begad! T' H70 has a 3 second burn time, and only has a total impulse o' about 180 n/s. Begad! Aye aye! I wanted a rocket that was light enough t' launch with t' motor, 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! I decided that t' Aerotech Mirage was t' perfect candidate. Blimey! It can launch on a motor as small as a F25, ya bilge rat, matey, and with me calculations, ya bilge rat, matey, 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, me hearties, me hearties, 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. Begad! Arrr! It had t' carry electronics t' deploy t' recovery system. Begad! Avast, me proud beauty! I wanted t' put a bulkhead near t' engine that will hold t' charge, me hearties, yet protect it from any leakin' N2O. Well, blow me down! But I also want t' option o' launchin' t' model with conventional motors. Ahoy! So t' charge bulkhead had t' be removable. Ya scallywag! Well, arrr, blow me down! Because o' this, 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. Begad! Arrr! T' Booster Section, Parachute Bay, me bucko, and Payload section. T' Motor Section be t' lower section o' t' Aerotech Mirage, and is heavily modified. Ya scallywag! T' motor hook is still used, shiver me timbers, me bucko, ya bilge rat, but t' motor hook is trimmed t' allow t' longer H70 motor t' pass beyond t' motor hook. Blimey! It is attached in t' position that t' hook locks over t' aft closure o' t' Hybrid, me hearties, and standard 29mm High Power motor. Ahoy! Also, ya bilge rat, this section has t' ventin' tube permeably attached t' t' airframe.

T' parachute bay, arrr, me hearties, matey, obviously, is where t' recovery system o' t' rocket is kept. Begad! Begad! 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. Well, blow me down! Avast, matey, me proud beauty! When t' booster section is attached, t' tube coupler presses t' bulkhead against t' ring. Avast, me proud beauty! Avast, me proud beauty! This creates a nice seal betwixt t' motor bay and t' parachute bay. Ahoy! When t' Mirage is flown with a regular motor, t' bulkhead is simply omitted.

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

Flight:

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

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

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

Summary:

Overall, ya bilge rat, t' Hybrid Mirage project was a success. Aye aye! We built a rocket that could fly on a Hybrid motor, shiver me timbers, and convention motor. Ahoy! 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 ;-).