Brief:

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

Recently, hybrid technology has come down t' t' Level 1 arena. Ratts Work.s be t' first company that offered a certified hybrid system that any level 1 user can use. Ahoy! 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. Begad! Begad! T' reload kits do nay require a hazmat fee, arrr, but they do nay come with igniters or pre-heater charges. However, some dealers (ie Pratt Hobbies) throw these components into t' kit for you. Avast, arrr, me proud beauty! T' Ratts Work Hybrid motors are designed t' fit in a 29mm motor tube, with slight modification t' t' rocket for venting. Ahoy! Also, ya bilge rat, t' fuel tank be t' same cylinder as t' oxidizer tank. Aye aye! T' fuel and oxidizer are separated by a .floatin' bulkhead.. Begad! T' fuel is consumed from t' top t' t' bottom. Ahoy! This means that t' pressure o' t' N2O pushes t' bulkhead down as t' fuel is consumed. Ahoy! They have three motor designations, H70, I80, me hearties, and I90. Well, matey, blow me down! 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! 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 be a rocket t' fly it in. Arrr! Well, matey, blow me down! T' H70 has a 3 second burn time, ya bilge rat, and only has a total impulse o' about 180 n/s. Avast! I wanted a rocket that was light enough t' launch with t' motor, and t' added weight o' t' recovery hardware, ya bilge rat, 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. Blimey! Well, blow me down! 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. My fifteen year old friend Ryan Sebastian wanted t' help out with t' project, so he became me partner in designing, ya bilge rat, and buildin' t' rocket.

There were a couple conditions that I wanted for this rocket. Avast! It had t' carry electronics t' deploy t' recovery system. Avast, me proud beauty! I wanted t' put a bulkhead near t' engine that will hold t' charge, yet protect it from any leakin' N2O. Begad! Avast! But I also want t' option o' launchin' t' model with conventional motors. Ya scallywag! Avast! So t' charge bulkhead had t' be removable. Ahoy! 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 was built with three main sections. Aye aye! Begad! T' Booster Section, me hearties, ya bilge rat, Parachute Bay, and Payload section. Ya scallywag! Begad! T' Motor Section be t' lower section o' t' Aerotech Mirage, ya bilge rat, and is heavily modified. T' motor hook is still used, ya bilge rat, but t' motor hook is trimmed t' allow t' longer H70 motor t' pass beyond t' motor hook. Arrr! Aye aye! It is attached in t' position that t' hook locks over t' aft closure o' t' Hybrid, and standard 29mm High Power motor. Ahoy! Aye aye! Also, this section has t' ventin' tube permeably attached t' t' airframe.

T' parachute bay, ya bilge rat, arrr, obviously, ya bilge rat, is where t' recovery system o' t' rocket is kept. Ahoy! It is also t' section that t' ejection bulkhead is attached to. Aye aye! Blimey! A paper rin' is attached inside t' tube so t' forward face o' t' bulkhead rests against it. Well, blow me down! When t' booster section is attached, shiver me timbers, 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. Aye aye! Well, blow me down! Blimey! T' electronics for t' recovery system is located in t' tube coupler. Ya scallywag! Arrr! Blimey! I decided that I would use me custom built timer for recovery. Ahoy! Blimey! I designed t' timer t' use a .burn wire. Ya scallywag! Avast! Blimey! t' start t' timer. Begad! Blimey! T' utilizes this, me hearties, ya bilge rat, me hearties, I had a couple short bolts stickin' out o' t' side o' t' rocket. Arrr! Well, blow me down! Blimey! Each bolt is a terminal which a .jumper. Ahoy! Blimey! wire is connected too. Begad! Blimey! T' jumperwire is fastened t' t' launch rod. When t' Mirage takes off, t' jumper pulls free from t' bolt, thus startin' t' timer.

Flight:

T' first opportunity t' try out t' Hybrid Mirage came on July 27th, arrr, 2002. It did nay work very well though. Aye aye! Blimey! There be a N2O leak in t' vent tube. Ahoy! Blimey! T' N2O filled t' motor section, ya bilge rat, ya bilge rat, and spread into t' parachute compartment. Begad! Just before t' countdown for ignition was started, t' N2O in t' parachute compartment pushed t' payload section off t' rocket, which started t' timer. Aye aye! T' countdown was aborted, me bucko, and t' N2O dump button was pushed. Avast! While t' oxidizer was bein' drained, t' charge went off. Aye aye! Ya scallywag! Blimey! Paper, Wood, ya bilge rat, Oxidizer.... Begad! Blimey! now a heat source? You guest it. Begad! 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, ya bilge rat, hopin' t' reload it. Begad! T' charge bulkhead be completely chard. Begad! It disintegrated just by handlin' it. Begad! Aye aye! Blimey! 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. Avast, me proud beauty! Robert Galjes could nay make it t' t' launch with t' ground support equipment and t' tank o' N2O, so Ryan and I decided t' launch it with a conventional motor, ya bilge rat, me hearties, a G75-10J. Ahoy! I decided t' arm t' timer too& just t' make sure it works. Ya scallywag! Blimey! T' lift off o' t' Hybrid Mirage was beautiful. T' black and silver rocket streakin' skyward, me bucko, me bucko, leavin' behind a dark smoke trail& nice :-). Well, shiver me timbers, blow me down! Blimey! T' timer deployed both chutes right at apogee, ya bilge rat, and t' rocket recovered without a scratch.

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

Summary:

Overall, t' Hybrid Mirage project was a success. Avast, me proud beauty! We built a rocket that could fly on a Hybrid motor, and convention motor. Begad! Begad! 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 ;-).