Stratoballoon Update

We knocked out a couple of key tasks earlier this week.

  • On Wednesday I ran an endurance test on the instrument pack.  I put in fresh Energizer Lithium batteries – the kind that we are going to fly with – and set the instrument pack up to run overnight.  It ran flawlessly for just over 7.5 hours, which is when I stopped it, and looks like it could have kept going.  That definitely answers the question of whether the batteries will last for the entire flight, and then some.
  • Also on Wednesday, Katherine and CJ finished the radar reflector that we’ll attach between the parachute and the capsule.
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    • On Thursday, I was finally able to get ahold of the proper person at the FAA to confirm what we needed to do to “register” the flight with them.  I have to call the Lansing Flight Service Station (FSS) 1-2 days before the launch to file a “Notice to Airmen”, or “NOTAM”.  That will go on record and let the nearest air traffic control (ATC) tower – in this case Kalamazoo – of the flight.  As soon as we launch, I need to call Kalamazoo ATC and the Lansing FSS to let them know.  When the balloon lands, I need to call them both again to let them know.  If we scrub, I need to call the Lansing FSS and cancel my previous NOTAM, and issue another one.
          Then today, we blew through a batch of tasks:
        • Today, we mounted the 1/4 wave ground plane antenna to the capsule.
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          • Next, we did a relatively full test of the packing procedure for the capsule in preparation for our “driving test”.  We were able to identify several steps that we had previously left out, as well as solved a few new problems we encountered.  The only thing we really didn’t do was load up the camera.  We still packed it since it’s an integral part of the capsule scheme that CJ and Katherine devised; we just didn’t turn it on.
          • We performed our shake test, and the capsule passed with flying colors.
          • Then we loaded up the primary chase car with both the eggbeater and the yagi antennas, our laptop, the SDR receiver, and an inverter that would allow us to power the laptop off of the cigarette lighter.  It took a little while to get everything situated, and again we identified a few places where we needed to come up with a better approach for launch day.
          • Katherine was able to get a lot of good experience working SDR# and dl-fldigi – the two main pieces of software that we’re using to translate the signals back into data.
          • Finally, it was on to the driving test.  CJ took the capsule, transmitting, in her car while I took the girls and the ground station equipment in mine.  CJ parked at one of the highest places in Kalamazoo, and sat down with a good book.  The girls and I then tried to drive as far away as we could before we lost the signal.  Because the capsule wasn’t very high, and was trying to transmit through trees, buildings, and the like, we were only able to get about a mile away before we could no longer pick up the signal.  Up to now, we haven’t had the transmitter and receiver more than 10 feet away from each other, so this test gave us a chance to really evaluate the effectiveness of the two receiving antennas.  We also learned what a “weak” signal looks like in dl-fldigi.  During the launch, the balloon will be airborne, with nothing but air and perhaps a few clouds between it and our receiver, so we expect the signal to go further.
          • When I got the capsule home, I popped out the microSD card and checked the data recorded.  In the 90 or so minutes that we were out and about, we got over 2200 data points.  I spot-checked them against Google Maps, and was able to follow the route that CJ took, where she stopped, and then (after transferring the capsule to my car for the drive home) the route I took, when I stopped, and when I got home.

          All in all, I think this was a very successful week.  Tomorrow’s major task will be to dye the parachute orange.  On Monday, I’ll be hopefully finalizing the helium supplier, and the equipment we’ll use to fill the balloon. 

          T-minus 10 days, folks!

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