Heuvos Launcheros Dos

One of the first things I did after moving to Austin was join the local branch of two national rocket clubs of which I am a member, the National Association of Rocketry and Tripoli.  It turned out that the two Austin clubs merged into a single organization at that same time.  This provided me with an opportunity to explore two areas of rocketry which were new to me, competition and high power.

The first rocket competition hosted by the local club I joined, the Austin Area Rocketry Group, was Heuvos Launcheros Dos.  This event was originally scheduled to occur on December 8-9, 2001, but was delayed due to rain until January 19-20, 2002.  The name of the contest is pseudo Spanish meant to represent that all the events involve launching a rocket with an egg inside.

There are two types of egg lofting events, duration and altitude.  The goal of duration events is to keep your rocket in the air longer  than anyone else.    In an altitude event , the contestants attempt to launch their rocket higher than anyone else.  Both of these categories are further divided by the size of engines allowed.

Since this was my first competition, I tried to research design and strategies as much as I could.  The rocket above was the design I decided to use for most of my rockets.  I used this particular model for B egg loft duration, the event with the lowest power engines.  My rockets for C egg loft duration and D dual egg loft duration used bodies exactly the same, but a different type of nose cone for holding two eggs was needed for the D dual egg loft model.  The power of the rocket motors doubles for each letter designation.  That is why a D engine is able to lift two eggs while a B engine can barely lift one.

The first event I actually entered was E egg loft altitude.  Because an E engine can lift a single egg rather high, I chose to use a small, 12 inch parachute.  The idea being a smaller parachute will let the rocket fall faster, therefore not gliding outside of the recovery field.  A small chute will fit inside of a minimum diameter body tube, so this rocket's design was different than the duration models.  I also decided to use a larger nose cone so more padding could be placed around the egg since the rocket would be falling faster.

As you may be able to guess from the picture above, everything did not go as planned.  In order to launch to as high an altitude as possible, I chose to launch in a two stage configuration.  This means one rocket motor is used during lift off, and a second motor is ignited after the first one burns out.  The rocket became unstable at some point near staging.  All I was able to find after the flight was the egg capsule and parachute.  Someone later found the main body tube you see in the picture, but without fins.  I never did recover the first stage.  Amazingly the egg was still intact, so I figured I would utilize it's luck in my next launch.

I then loaded my lucky egg into the B egg loft duration rocket you saw earlier.  As I mentioned before, I chose this design after a lot of research.  The paper shroud section provides a large storage area for parachute material, while providing a very aerodynamic transition between the large egg capsule and smaller engine.  I used the biggest parachute I happened to have at the time, 24 inches.  This time everything worked perfectly.  My rocket actually went up a couple times while floating under the parachute.  The rocket finally touched down after 62 seconds, earning me second place in this event.

As I was preparing my next rocket for the C egg loft duration event, I remembered I had brought along my camera.  Evidently I was so nervous about flying in my first contest that I forgot all about it.  This resulted in only getting pictures of my C egg loft duration rocket actually at the launch site. The picture to the right shows my rocket in a launch tower.  The tower is used to guide the rocket in a path straight up for the first three feet.  Until then the rocket is moving too slowly for the fins to provide any guidance.  Otherwise the rocket may fly sideways, something you would not enjoy if it is heading straight for you.

This picture shows my C egg loft duration rocket shortly after motor ignition.  Thanks to the launch tower, the flight is very straight.  It was a very nice launch, but trouble started once the parachute was ejected. At least one of the shroud lines on the parachute became tangled on the rocket.  It  most likely got snagged on one of the fins.  This accident prevented the parachute from completely opening, therefore causing the rocket to fall much more quickly than my previous attempt. So despite launching to a higher altitude with the more powerful C engine, my flight lasted almost half as long at 38 seconds.  Luckily almost everyone else had more severe problems during their launches, so I managed to earn a second place in this event as well.

My final picture shows the C egg loft duration rocket ready to be launched again.  You can see how much larger the duration parachute is compared to the one used for my altitude attempt seen earlier.  The kevlar cord which connects the parachute to the rocket is glued to one of the fins at the center of gravity.  This causes the body of the rocket to hang sideways providing more friction with the air.  Some of the padding I used can also be seen inside the egg capsule halves.

Unfortunately I ran out of time and could not attempt any more flights.  Overall I was rather happy with two of my three flights ending successfully.  In fact, this was enough to put me in second place for the entire contest.

I plan to reuse my B egg loft duration rocket in my next contest, April Madness, at the end of April.  The rest of my contest rockets will be brand new since the events will be different.  I will be sure to make another update with the results of that contest.