NSL-68

We learned of an opportunity to help-out with a 360-degree camera project in November 2018. Although winter-time can be a challenge for flying due to the strong jet stream winds, we figured that if we timed it right, and gave the flight plenty of room to travel, that we could be successful.

One challenge with 360-degree cameras is mounting them in a way that they can "see" all around. To reduce obstructions for this camera, it was suspended about 3m below a box of tracking gear. It was suspended by a string and a USB umbilical providing additional power. The tracking box (from NSL-67 et.al.) held the following:

• A 'power bank' battery pack for additional power to the 360 camera

• 808 #16 camera looking down at the suspended 360 camera

• AP510 APRS tracker

• Outside Hung Compact Rain-Activated Pull-down

• Raspberry Pi Zero with GPS, camera, LoRa and modified PITS (Pi-In-The-Sky) software

The parachute was adjusted for a slightly faster than usual descent, just in case.

We were watching the weather closely and eventually chose the morning of Sunday, Nov 25, 2018 to launch. To keep the payload out of the ocean, we launched from Bray Park in Siler City, with hopes to land west of Greenville, NC. A 600g balloon was filled with over 2500g of neck lift of H₂. Any less and we risk a wet landing. This much gas may prevent us from reaching 35km, but super high altitude wasn't a requirement for this test flight.

The morning was chilly, so we quickly assembled the payload and filled the balloon; all the while, discussing how we would coordinate the fast release of the payload. We waited until the last moment to activate the video cameras and then released the balloon. With that much neck lift, the flight took off like a shot -- we planned for that, but were still surprised by its speed. Then we quickly packed up and high-tailed it towards Greenville.

As the flight ascended through the morning fog, its ground-speed increased, at times exceeding 250km/h ! The chase crew, driving only half that speed, fell behind. The poor camera hanging below was swinging like a pendulum.

At 16km over Wilson County, the flight rose above the fastest jet of winds and slowed down its horizontal drift. This gave us a short opportunity to try to catch up. The layer of mackerel clouds seen in the early morning, started to dissipate, revealing a beautifully sunny day.

The balloon burst at 97,600kft.

The chase crew converged upon the projected landing area but arrived about 5 minutes too late to watch it. As usual, the APRS tracking gear was unable to reach the regional iGate once below 500m, so portable receiving gear was used to pin-point the exact landing place. There are lots of large open farm fields in that part of the state; so of course, the payload landed up high in a tree overlooking a soybean field.

The Pi camera operated until early the next morning, catching the views of sunset from high in the tree.

Light rain was expected the next day, which would activate the spool of string. So it was decided to leave the payload up the tree. The landowner also "knew a guy" with a bucket truck. A couple of days later the entire package was retrieved successfully.