Clustered Shadow Launch Report (LONG)

Date:    Wednesday, December 9, 1998
Time:    3:30 p.m. EST
Place:   My backyard, NE Ohio
Weather: Sunny, ~40 degrees F
Winds:   W ~5 mph

My son was home from school with pinkeye. Not being a debilitating condition,
but something the schools don't want spread around; I got to spend some (paid)
quality time with him. I had finished the paint and decals on my Shadow "5" just
after Thanksgiving, but hadn't had ideal weather yet. This turned out to be the day.

I have modified Estes' "The Shadow" (#2094) by adding 4 18mm MMTs around the central
24mm. The center MMT is in the aft end of a stuffer tube running to within about 8"
of the top of the rocket. Using a series of holes and "blocks" I created a means for
ducting the outer engines' ejection charges into the stuffer tube, and also created
a baffle further up the tube. Details and photos of the construction are at "shadow5.htm"

I previously launched this rocket (pre-paint) on a single D12-3, using four spent
engines with masking tape on top to plug the outer MMT holes. I eventually plan to
go up to a D12-5 with four C6-5s, but was not ready for that just yet.  This day's
launch used a central C6-3 in an 18mm to 24mm adapter, two B6-4s, and two A8-3s. I
knew the A's delays would be short but wRASP showed the velocity at 3.5 seconds
total time to be slow enough to not cause any alarm.

I took the battery out of my car and headed out to the back yard ("540 cold cranking
amps" light 5 Estes ignitors quite reliably!).

First a wind test:
Maniac on a C6-5 (using 18mm to 24mm adapter)
I noticed some missing clay around one side of the engine nozzle but figured "what the
heck". This was the first launch with my homemade controller and the car battery. I'm
so used to the delay between button press and ignition with the Estes controller
(4 AAs) that it seemed like the Maniac anticipated the launch! The asymmetric nozzle
was immediately apparent. The rocket spun slowly as it ascended and gradually arced
over to a horizontal trajectory at burn out. This is when those short Estes delays
are appreciated! The Maniac was no more than 100 feet off the ground when the chute
popped. At least I didn't have to chase it forever like when we use those D12-5s.

Now that I had gauged the wind, not, I was ready for the Shadow "5":
The new controller has five pairs of leads and clips, but the hardest part of prepping
for launch is getting all the ignitor wires away from each other. I know some can be
twisted together, but I want to be able to check each ignitor's continuity to ensure
all five will fire. I put a continuity test/enable switch in my controller for each
pair of leads. My son manned the video camera and I got to do the countdown (something
he usually does). The car battery did not disappoint, all five engines lit and the
Shadow "5" headed *straight* up. I can be heard saying "Wow" on the tape. Then
near-disaster: two engines ejected way early and blew out of the friction-fit MMTs.
The nose cone blew, but the rocket was still moving up and there wasn't enough force
to push the chute out. The Shadow "5" arced over and I hoped the drag on the nose cone
would pull out the chute, but it was soon held in by the now downward accelerating
rocket. I can be heard screaming "Oh no" on the tape. The Shadow "5" did a nearly
clean 2" core sample and remained vertical. I really had to pull hard to get it out.
Fortunately, the only damage was a crimp in the edge of the tube (see photos on my
site listed above). No other crimps or buckling. The crimp was pulled out and
strengthened with thin CA. A little filler, sanding, and spot painting and it’ll
be good as new.

My son and I both had a good time, and my wife got a kick out of our son’s videography
and newscasting skills when she got home from work.

I hope to launch the "D & 4Cs" soon, and I’ll use more wraps of tape on the outer engine
for that.