Thursday, August 15, 2013


I ordered the balloons and parachute. All total (shipped), $218.46. That's for two balloons (in case we pop one, or want to do a second launch) and a 6.5' parachute.

The balloons are from Project Aether (shipped from Amazon). The parachute is from The RocketMan.

The payload plans have been modified a bit to fit everything we want to do, and have redundant failover.
The ATV equipment requires 12v (not 7 as we were going to run), so I picked up a 12v Lithium Ion battery pack. We can now have 12v on board.

I've got 4' of the nichrome wire we're using to cut the payload down. This will be powered by a single 9v battery, as the draw from the nichrome wire could be enough to shut the battery pack down and terminate all other equipment.

We're going to run 3 separate Arduinos, for redundancy and to ensure everything operates smoothly.

The first is the Trackuino, which is currently on the air at Dan - K8PLW's house (!call=a%2FK8RDM-11).

The second is the beacon transmitter, which is online at my house (minus the transmitter). It's currently outputting to a set of headphones in a 24 hour stress test. This arduino will loop an MP3 transmission endlessly, with a 2 minute pause in between. It also provides a logic high voltage out on one of the pins when it is transmitting so we can key the PTT on the Icom 2AT.

The third is for the DTMF decoder / cut down mechanism. This cut down mechanism is currently in development by John - K8YYZ. He's setting up an MT-8870 to decode the tones and after a multi-tone input (which will be highly classified), trigger a relay for the 9v battery for the cut down mechanism.

Steps still left to complete:
  • Finish cut down Arduino.
  • GPS out of the Arduino for the ATV team to overlay to the transmitted video signal - I don't think this will be difficult. We have the data in the Trackuino. I may have to defer to K8YYZ, as I wrote my first arduino code last night for the beacon.
  • Get Helium.
  • Get the ATV Equipment and get it in the payload
  • Confirm launch location
  • Obtain payload cordage
  • Secure and assemble the payload
  • Weigh payload all assembled 
  • Notify the FAA
I'll be bringing the Beacon, Trackuino, and everything else I can gather to the Hot Dog and Corn Roast for a little show and tell.

Finally, I'm fairly certain there's no way we can make the August 24th date. Things just have not fallen into place as quickly as I'd hoped. I don't have the ATV equipment yet (and won't have time to drive over and pick it up until probably next week). I'll start polling for future dates here shortly.