I'm using head end ignition and the igniters are installed with the electronics from the start. In addition to the switch controlled by the Blue Raven, there is a magnetically-activated switch that disconnects the battery from everything, and on top of that there is a screw switch that disconnects the airstart igniter even when the altimeter is powered on and the deployments are armed. That makes 3 inhibits for 2-fault tolerance. But to avoid any doubts about safety, I also keep the motor propellant grains out of the case until I get out to the pad. This makes for a less useful RSO check, since they have to take my word about the fully-loaded center of gravity, but after some good questions and discussion, and a nice distant pad area assignment from Deb Kolombs, I passed the RSO check and went out to the pad with Paul, a Wyomingite who nonetheless was part of our Colorado contingent. (also I want to give a shout-out to Larry Haynes and Vic Davis, who dragged all my stuff across the west so I could fly into Reno and provided the best food and accommodations on the playa).
This is my first attempt to fly with snap-ring motors, so after I installed the motor grains into the 2nd stage motor, I made made the comical mistake of trying to install the nozzle backwards. It promptly stuck, and so I had to go back to our prep area to take it apart to reverse it. To push the nozzle out from the forward end, I needed to take out the 2nd stage av-bay and a cross-bar that is drilled across the forward closure. I got that done and took the rocket back to the tower with my tools, and installed the nozzle the right way this time, and got the snap ring in. In the meantime what I didn't realize is that when I re-installed the cross-bar, I failed to thread it back through the little loop of kevlar of my 2nd stage recovery harness.
Back out at the pad, after installing the 2nd stage and nozzle, I installed the upper stage grains and nozzle. The rocket stages had to be assembled within the tower, and with Paul's help that went o.k. Then I armed the booster deployments, the 2nd stage deployments, and the sustainer deployments, and then armed the sustainer airstart and the 2nd stage airstart. In the meantime the guy on the C pads next to us with a scale AMRAAM had been ready to go since before I realized the backwards nozzle, so we snapped a couple of pictures and quickly departed. On the way back I realized I hadn't double-checked the tower straightness from all angles like I normally would. But it seemed at the time it was straight. In hindsight I should have just gone back to LCO to get the AMRAAM off and then gone back to the tower to re-check everything. But I was pretty frazzled by this time and started to get worried about the sustainer tracker battery, which was now down to 3.7V after about 3 hours of prep. So yeah, I've got to admit a caught a case of go fever.
If anyone has a video of the launch, I'd like to see it. The K1127 motor lit and had a nice purple flame, but the rocket left the tower tilted noticeably to the left. After motor burnout a lot of stuff happened fast, and from 1500' I couldn't quite follow what happened. But the booster and second stage parachutes appeared quickly, and the Featherweight GPS told me that sustainer apogee happened at a little over 12,000 feet. Then the sustainer came down fast. Too fast. The last packet showed it came down at 293 feet/second a little over a mile away, and it was time for recovery.
When we walked in the direction of the sustainer tracking, the booster and its chute were visible right away, and I could see another piece off to the northeast. That piece turned out to be the second stage sans av-bay or chute:
Sadly, 2 fins were broken on the impact. I figured that the 2nd stage kevlar harness had broken, but later I found the intact harness loop, which told me about the mistake I made re-threading the 2nd stage crossbar. Paul and I met up again and I was happy to see that the booster was recovered intact and as designed. I went off to get the sustainer by myself. The last tracker position was about a mile away at this point, and as I walked in that direction and my range got down to about 1/2 mile, I saw a pickup truck stop about where I thought the rocket was, while I watched them with binoculars. It was a pretty helpless feeling watching someone do something to my rocket but be too far away to waive them off. Note to people at launches: Please don't touch rockets you found unless you know there's almost no chance the owner is still at the event. Instead, just note the location and let the LCO know where you saw it. When I got to the rocket it looked like this:
The unburned motor, with head-end igniter installed, was out of the rocket, with the the head-end igniter wires broken. I have been assuming that the motor was pulled out of the rocket by the people who found it, but now that I think about it, if the motor were inside the sustainer when it landed, I think it would have been buried much more deeply. More likely it fell out when the main chute deployed at high speed, and the people I watched just found it separately and set it next to the rocket.
The main chute had shredded, indicating that my apogee deployment failed to eject the nosecone, but the main chute deployment blew the chute out and the nosecone. The nosecone ejector, piston, and main chute piston were scattered around the vicinity of the rocket and I picked them up, but the rest of the chute was nowhere in sight. Fortunately there was no significant damage to the chute cannon which was buried in the mud, but the front 1" or so of the nosecone broke off.
I'll show a more detailed look at the recorded data later, but the initial look at the sustainer data showed that when the apogee charge fired, there were 8-10 Amps of current but no acceleration, indicating that the leads had shorted, which explains the failed apogee deployment. The apogee wire has a bit more un-stripped insulation in image 9832, but I'm not sure whether the problem was there or somewhere else.
The mystery of why the rocket took off at an angle was solved once I went back to the pad. One of the three tower poles was kicked out to the right. It was one I apparently forgot to tighten down before we left the pad last time. That one stings.
Why both separation charges went off right after the first motor burnout was explained by taking a closer look at my deployment settings. It turns out that I had accidentally set the 2nd/sustainer separation to go off after a motor burnout count of 1 rather than 2. User error. Interestingly, without the sustainer attached, the 2nd stage has so much motor sticking out the back that it is stable going backwards, so after the sustainer separation, it immediately did a 180 flip and continued upward facing backwards until it ejected the av-bay at apogee.
More to come later, but first I need to unpack, etc