Summary Video of Launch Two

The data is still being processed, but here you can see the video from the flight module.  Thanks again to our sponsors, Jackson Labs and Byonics!

Thanks to our Sponsors!

First of all, I'd like to send a big thank you to a couple of our very generous sponsors, Jackson Labs Technologies as well as Byonics, without whom our latest launch would not have been possible.  Jackson Labs supplied us with a board that uses GPS to keep incredibly precise timing which was necessary to correlate events on the Geiger counter to events measured elsewhere.  Byonics provided the GPS tracker that worked incredibly reliably, making it possible to recover the flight hardware.  Thank you!

Analyzing Launch Data

While we were not able to recover the payload from our launch last Friday, we did learn a lot about what to expect for future launches and where we can improve.  The good news is that the tracking system worked impeccably, even after experiencing much more extreme conditions than expected.   Below you can see the flight path of the payload.  The balloon traveled over three times the distance we had hoped it would travel due to under-filling the balloon with helium. 

The following graph shows the elevation profile.  Our average ascension rate was about 48 meters per minute.  At the next launch, we hope to achieve an ascension rate in excess of 200 meters per minute.  You can probably notice some strange data in the graph below.  Specifically, elevation decreases and then increases again.  This could be a result of bad GPS data.  If it isn't, it's interesting. Perhaps there was an intense pressure gradient that caused the balloon to actually decrease its altitude. 

Below you can see precisely where the anomaly occurs in 3D view.  Also, a little while after the reported decrease in altitude, there is a half hour where the altitude essentially doesn't change at all.  It could be that we had less than 4 satellites locked during this time leading to latitude and longitude data, but no altitude data. 

More photos and video of the balloon launch will follow.

Status Update

Here you can see the latest data on where the balloon is.

Launch 1

This afternoon we launched our first balloon. It is in the air at the time of this post.  You can track its progress here:

http://aprs.fi/#!mt=roadmap&z=11&call=a%2FKC8DRG&others=1&timerange=3600

Assembly for Flight 1

Here you can see the flight module for test flight #1.

Thermal Test

To ensure my the reliability of my flight hardware, I conducted a test where the conditions at 100,000 feet were simulated.  To do this, I used a cooler, a 12 pound block of dry ice, a mounting system, and a temperature sensor.

Here you can see the big block of dry ice I used to get down to the desired temperature.

Here you can see the flight hardware packed inside the polystyrene foam container.  The Geiger Counter, DAQ system, and camera were all placed inside and turned on.  I placed a couple pieces of Uranium glass inside so the Geiger Counter had something to record during the test.

This is the setup inside of the cooler.  The best way to get really low temperatures around the box was to place the block of dry ice above it.  I used some more pieces of polystyrene foam to mount the dry ice above the box.  You can also see the temperature sensor that I used to derive the temperature inside the cooler.

 This is a picture of the box before placing the dry ice on top.

Now the piece of dry ice is placed and ready to go.

I put the cooler lid back on with the temperature sensor wires connected.  The equilibrium temperature inside of the cooler and outside of the flight hardware box was found to be -36 degrees Celsius, right around what I expect the temperature at 100,000 feet to be.  After two hours, a thermal equilibrium was established with a temperature of -5 degrees Celsius inside the flight module.  The heat generated from the electronics and excellent insulation properties of polystyrene foam aided in establishing this equilibrium.  At the conclusion of the test, all of the electronics were still functioning perfectly.

Overall I was pleased with the performance of the electronics under the conditions.  The next task will be to perform the same experiment with hand-warmers placed inside the flight module.  In doing so I hope to establish a factor of safety by running closer to the middle of the operating temperatures of all the electronics.  Further, temperatures will actually be lower than -40 degrees Celsius on the journey up to 100,000 feet, so having some active heat source other than the electronics themselves will be critical.