Some Pictures & Facts About BLT33.7 (AF5LI-11)

We have recycled the Pecan Pico 3 from the previous launches on the weekend and decided to re-launch it at optimal weather conditions. It just happened that the predictions were favorable on Wednesday evening, right when we had our preparations meeting for the big August launch (BLT34). So we met all together at the “Secret Sugar Land Space Laboratory” at Mike’s house (WA5TWT). Instead of making much progress with the BLT34 main package we’ve launched 3 mylar balloons.

Here’s some data:

3 Mylar balloons with approximately 11 g lift each

Payload weight 26.2 g

Measured free lift with attached package: 6.5 g

One Energizer AA Ultimate Lithium battery

Photos by W5ACM

The K5W-11 Balloon (BLT33.5 and BLT33.6)

Two short flights and two recoveries with this special event callsign. At Walter Holmes “Ham Splashfest” we had the opportunity to use a two letter callsign for a small balloon experiment. A single 30″ mylar balloon was equipped with a Pecan Pico 3 tracker and a single AA 1.5 V lithium battery. Unfortunately the rain hammered the balloon down after a few minutes so that we saw him landing 4 miles North West of K5WH’s home QTH. An immediate recovery attempt in pouring rain was successful though we had some trouble with picket fencing. The balloon was still full of helium and the beacon was still transmitting. Therefore we just put it for an hour in Walter’s garage until it dried up and was ready to launch again. We didn’t even have to supply new helium.

The second launch was much calmer and the little mylar climbed up to 14,118 feet. But then suddenly it dropped down like a stone and at 5000 feet we lost signal. It was already too late for another recovery attempt, so we decided to try again on Sunday morning. When we arrived at Metzler Elementary School we mounted a high gain antenna on the car roof and were disappointed that we didn’t pick up a signal from the tracker. We were driving through the neighborhood but it didn’t seem very promising. What now? Sven reviewed the flight path short after launch and it seemed that ground winds came mainly from South on that day. So our best bet was to head North. Pecan trackers have a very characteristic sound. They transmit two packets in a row with approximately 5 seconds delay. Suddenly Sven said: Stop! I believe I heard the Pecan! We stopped the car and waited another 2 minute cycle and sure enough we got a complete position packet from K5W-11. That was half the battle and we were happy as kids.

Looking up the position on the map pointed us to a location even further North. Signal became louder and we heard almost every packet. The battery was very healthy and the temperature showed temperatures above 50 deg. Celsius which means that it must lie right in the sun. However the signal was not too strong at some distance, so it was likely not hanging in a tree. We walked through the neighborhood for a while but couldn’t determine the exact location. The positions were jumping around several hundred meters and all houses were fenced. After an hour walking in the mid-day heat we decided to go to the nearby Mexican restaurant and simply collect some position datapoints and average them in a spreadsheet. The restaurant had excellent food and data was converging quite clearly to a distinct house which we have passed before without seeing a balloon. Anyways we went back to that house and looked around before attempting to ring the bell. Sven discovered the payload lying right in the middle of the sidewalk!  – without any balloon attached to it. That’s why we haven’t seen it when we passed by it in the car earlier. The beacon was still transmitting and looked in good shape. I’m sure it is good enough for the next launch 😉