[GCARC] Disappointing balloon flights on Sunday

[Jon Pearce]

We had two disappointing balloon launches on Sunday, September 15th. Mike KG4JYA, Jim N2GXJ and I launched two balloons, one using the higher-cost SBS scientific balloon with ZachTech tracker and the other using the lower-cost ORBS balloon with Traquito radio transmitting WSPR signals on 10 meters. Our hope was that at least one of them would successfully rise and start following the wind currents, which at that point were moving northwest and would have taken the balloon over Chicago, circling through Canada and finally reaching the Atlantic Ocean off the northern Canadian coast. Because of its larger size we filled the SBS balloon with helium to create 6.5 grams of net positive lift, slightly larger than the 5 grams we had used with the ORBS balloon.

The winds were moderate, between two and four mph, and we waited for a calmer moment to launch each of them. Both of them cleared the towers and the trees and rose slowly into the sky. We had to wait about 15 minutes for telemetry to arrive and be decoded, and we did receive packets showing the SBS balloon rising slowly and moving southwest towards Delaware. Unfortunately, it unaccountably rose and fell, rising to about 3500 feet and then falling to 1800 feet, rising again to 2500 feet as it crossed the Delaware River into Delaware and then Maryland. Its last transmission showed it at 1700 feet several miles west of Elkton, MD. It's probably on the ground somewhere there but the solar cells wouldn't be receiving sufficient sunlight to run the radios to send telemetry.

The ORBS balloon with the Traquito tracker rose beautifully, but we never received any telemetry from it. It had been transmitting successfully for more than a week at Mike's house and the LED on the board was flashing to indicate a GPS lock before it was launched, so we don't know why we never received telemetry.

We need to brainstorm our next approach as it is not apparent that we are doing anything wrong. These experiments contain large amounts of luck, so we may have simply been unlucky a few times and can continue with the methods that others have found to be successful. It appears that there will be temporary flight restrictions this coming weekend, so no launches are planned, but we would like to have a successful flight before the STEM club sessions at Woodruff School starts launching their balloons in about a month.

73 de Jon WB2MNF with Mike KG4JYA and Doug KD2VQA