It really starts to take shape

One major step closer to launch today. All the ordered parts except for the temperature and pressure sensors arrived in the mail this afternoon. chdk loaded fine in the camera and a stock intervalometer script worked first time out. We'll modify it from there and add video triggering. The new GPS from Argent Data Systems is built to work up to at least 25km altitude. Shea wasn't expecting her parachute to be in her favorite color and monogrammed with the project name so that turned out to be a fun treat (it's the little things, right?). And finally, our two balloons. They are a bit heavy in stock condition because of the way the fill neck is designed and the skirt that hangs from the bottom. I've read of others using these particular balloons cutting off the skirt and modifying the neck to cut down on envelope weight. I'll unpack one of these later this week and we'll decide what we want to do modification wise. Right now, we'll be hard pressed to break 2.5 pounds in the payload so the extra lift gained by the mods may not be all that necessary. This is such a light payload, I really wish I had time and money to put more of my stuff in it. Next launch....

Pretty much the whole kit in unassembled form. Payload box, camera, C&DH microcontroller, radio, GPS, parachute and balloon.

More parts

Well, as of this afternoon, most of the major components for Project DEBO are ordered and either shipping or waiting to ship. Next week should be busy with payload construction and testing. Today saw an order go out for balloons, recovery parachute and the temperature and pressure sensors. Thanks to Dale at orionspyramid, Mark at Rocketchutes.com and the gang at Sparkfun for making spending money sooooo easy. (I'll post something of a technical breakdown for the geek crowd over the weekend.)

Shea had to work through some balloon ascent/parachute descent simulations last night to pin down which balloons and parachute we would order. Once we had that, it was all eCommerce. I think, the only major component still to be ordered is a GPS unit rated to work above 18km. Both units I have here will fail above that. Since we hope to make it to 25-30km, I don't want to lose tracking information for what could be a crucial part of the flight. We'll need some incidentals beyond that (and Helium, can't forget Helium...) but we should have everything needed to put the payload together and start testing.

Parts are rolling in

Well Project DEBO has a body and eyes now. I picked up a small styrofoam container (like the ones used to ship insulin) from the lab and we pulled off an auction win on eBay for a Canon Powershot A530 camera. This camera works with the Canon Hack Dev. Kit (chdk) so we will be able to script camera actions during the flight.

Now that we have a camera, Shea needs to work on a quick mass estimate and then do some ascent/descent predictions with online calculators so we can size balloons and parachute. I'd like to get those ordered in the next couple of days.

Shea's first arduino code

One more step toward her eventual balloon flight has started: teaching her how to write control code for an arduino microcontroller. She took to it pretty well and quickly had a couple of LEDs blinking on and off. Tomorrow we talk about reading sensors.

/*
Blink
Turns LED on and off repeatedly
*/



void setup() {

pinMode(12, OUTPUT);
pinMode(4, OUTPUT);
pinMode(2, OUTPUT);
pinMode(8, OUTPUT);

}

void loop() {
digitalWrite(12, HIGH); //1 on
delay(500); //pause
digitalWrite(12, LOW); //1 off
digitalWrite(4, HIGH); //2 on
delay(500); //pause
digitalWrite(4, LOW); //2 off
digitalWrite(2, HIGH); //3 on
delay(500); //pause
digitalWrite(2, LOW); //3 off
digitalWrite(8, HIGH); //4 on
delay(500); //pause
digitalWrite(8, LOW); //4 off

}

High altitude balloons + Middle school

When my daughter first started talking about her upcoming science fair, I didn't think it would go in this direction. This would be her first real science fair and her first fair at a new school. She brainstormed for ideas and, with mom a planetary geologist and dad an atmospheric physicist, she was not at a loss for them. She really latched onto the idea of measuring the atmospheric temperature and pressure profile with a balloon though.

I hope this blog will be a fun place to share the development process and record her work on it. We will use amateur radio for tracking and telemetry so this will also be the place for posting transmitter and telemetry decode information.

The idea is simple: launch a balloon into the stratosphere carrying temperature sensors, a pressure sensor and camera. An Arduino microcontroller will run command and data handling (C&DH) for data collection and storage. GPS coupled with amateur radio will provide position and data dowlink. In the event that we can not recover the balloon, the hope is to have the downlinked data for a backup. We will publish our downlink info and try to give warning about launch times. Radio amateurs along the flight track (likely Cumberland, MD to points east) are welcome to listen in.