PENS-4 was flown during the GPSL 2012 in Omaha. Nebraska. Helium was not accessible so we had our first

experience with hydrogen. Beside the traditional tracking hardware, there were several experiments being flown

other schools and organizations. Most of the experiments were under the control of Paul Verhage. We were

excitred to fly the "Smart Screamer" on this particular flight, just to demonstrate it to the GPSL group.

This is the "Smart Screamer". It is nothing more than 120 db audio siren which is attached to a picaxe 8M and a pressure sensor. In a nut-shell, when this device is turned on, it figures what altitude it is presently at and then starts a three hour timer. If the balloon becomes a floater (never goes above 5,000 feet above launch altitude) the siren goes off for five seconds, every 15 seconds. When the balloon exceeds 5,000 feet above launch altitude, the siren will go off when the balloon descends to 5,000 feet above launch altitude. The purpose of this device is to be able to hear where the balloon is, in the event you cannot visually see it.

This is Paul attaching all the experiments and rf tracking devices to the load line.

Holding the balloon when it is full of hydrogen.
As hydrogen passes through the valve, it gets really cold.
Pre Launch
The Launch
Thank goodness, we had the screamer attached! PENS-4 landed in the middle of a corn field (hey, it's Iowa) and even though the corn was only 18" tall, it totally concealed the entire flight string and parachute. As we walked out towards the direction of the landing, we heard the screamer and were able to walk right towards it.
Wilbur was so excited about a space-craft landing in his field that he had to come with us to see for himself.
Watch PENS-4 return to earth and land.
Listen to the screamer working.