First Aerotech

Lots of spectators at half-blast, but not a lot of flyers. This allowed me to have unexpected time to prep my rocket for flying.

I had just purchased 54mm 2560 Aerotech hardware so this is the first major launch using Aerotech RMS style motor. For my thoughts on Aerotech, read the comments below.

Winds were gentle from the southern direction.

Assembly of the rocket went smoothly. I installed the phone into the bay, closed the bay, installed the sheer pins and was just about ready to take my rocket to the pad when I heard a phone call come in. Oddly, I heard my app mention it had gone to the background on receipt of a phone call. Normally when you receive a call, you see a display of the call, but the foreground running app is not pushed to the background. Everything appeared to recover fine, but I was afraid I would not receive video since Android requires your app to be in the foreground to record video. Later, I found that if you receive a call marked as a SPAM, the OS temporarily pushes the foreground app to the background to give you better WARNING of the spam call.

I decided to remove the sheer pins, open the bay and inspect the phone. All of course was fine, inspection or reboot or change of the phone app was completely unnecessary. At least I had peace of mind the app would record video. I love the onboard 4k video.

Due to this random act of unluckiness, I have now added to the app a voice message letting me know that app is back in the foreground. Had this message been in there, I would have known everything was fine and continued to the launch pad.

I was fairly fatigued between assembly of the new motor and the oddity of the App so I was real careful taking my rocket to the pad, arming the electronics, confirming battery strength, etc.

While waiting for my rocket in the launch queue and being fatigued, I didn't notice a large cloud had drifted overhead or I would have told LCO to hold off until it passed. This is unfortunate as I don't like punching holes in large clouds. The launch was spectacular, but did go through a cloud.

Voice from the GRMS radio was intermittent due to an shoddy connection with the phone. This lead to us having no clue where the rocket was until after touch-down. Next time I'll stick to bluetooth to connect to the GRMS radio, the connection has proven itself reliable. I like testing different configurations to increase my launch options. This is critical learning for when I go out west for my one chance shot of launching really high. Plus I love experimenting.

Recovery was easy and was not that far away. Using the web page from the Kindle was awesome as it is so easy to view in bright sun. A little less launch angle would have landed the rocket right on the field. Rotation was gentle, but did pick up speed nearing apogee, maybe due to wind.

Lessons Learned:

1. Use a bluetooth connection, or get different microphone jacks that snap in better.
2. I now am confident assembling Aerotech 54mm hardware.
3. The phone was unusually hot this launch. My guess is it is due to my bay redesign having a really nice shock absorbing foam resting up against the entire front of the phone's glass. This is acting as an insulator and not allowing the phone to dissipate heat. I'll shave off about a quarter inch of the foam, install vertical balsa ribs covered in graphite(for heat dissipation) so there is some air space between the foam and the phone. While it stayed 20 degrees cooler than overheating, the battery temperature was 120 degrees and that is just too hot. In the summer it would surely overheat.
4. I need to add a thin amount of epoxy to widen to the lower electronics bay bulkhead to widen it slightly as there is too much gap and ejection charge is seeping through.