NSL-80

NSL-80 flew on the late afternoon of 9 February 2020, in hopes of videoing the NG-13 Cygnus rocket launch up the coast at Wallops Island. Sadly the rocket launch was scrubbed at T-3 minutes. So this ended up being simply a pretty sunset flight.

The payload consisted of the NSL-76 flight hardware with some slight changes. Below the 1m chute was a small box with an AP510 tracker and a nighttime strobe light (old xenon type from NSL-32). 3m below that hung another box with Mobius Mini and 808 #16 cameras.

Paul added the Raspberry Pi/LoRa/GPS/camera system from NSL-75 to the camera box. The Pi held a new, clean Raspian image and the latest Pi-In-The-Sky software. He had run into issues with PITS image software crashing while trying to rotate images, so this time he left out that extra code step and simply flipped the entire module. This placed the LoRa antenna atop the payload and the GPS antenna near the bottom. Not ideal, but at least the images would appear right-side-up. The Pi would take photos every 20 seconds, and then every few minutes would pick the largest image file (roughly the most visually complex) and transmit it back to Paul's receiver in the chase car. In addition to live images, the Pi also sent back tracking telemetry, inside and outside temperatures, and an on-board calculated landing site prediction. The images and data all appeared live on Habhub.org.

Timing the flight to coincide with the NG-13 rocket attempt required picking good launch/landing sites based upon the predicted winds that also provided a decent chance of viewing the rocket. Flight paths in Virginia would give the closest views, but they either strayed too close to exclusion areas or the landing areas were too tricky to achieve. Paul decided to fly from a park north of Hillsborough, NC so that the landing area would be in the cotton fields of Tarboro, NC -- an easy drive. The drive time from launch to landing was still long, so the operations team had to split in two. Paul and Matthew L. would fill and launch from the park and then make their way east. Meanwhile, Tim W. would monitor the NG-13 rocket and then after balloon-up head directly to Tarboro to be there ahead of landing.

Paul and Matthew arrived at the park 40 minutes before the required release time. A surplus Kaymont 600g cell was filled with 2200g neck lift of H₂ to send it aloft.

At the scheduled "balloon-up" time, the NG-13 launch was still "go". Matthew released the payload.

All system behaved themselves. The Pi transmitted "live" images back to the chase car gateway. Occasionally the gateway lost packets when the car went under overpasses or ventured outside of range (~50km). Paul only used a simple roof mag-mount antenna and not his high-gain Yagi.

Per plan, Paul and Matthew packed-up and drove east, trying to stay within range of the LoRa signal. [Setting up one of the additional gateways in North Raleigh would probably have helped with reception.]

Meanwhile, Tim left Raleigh for the Tarboro landing area.

The cheap Pi camera returned images with many unusual lens artifacts [need to swap out for another pinhole camera]. Ascent continued without issue.

While Tim was on the road, Chris G. joined in remotely as Public Affairs Officer and kept the team updated on NG-13's countdown. At T-5 minutes there was a hold and then a scrub due to some sort of ground system issue. Too bad.

But it was a nice evening for a chase. Beautiful sunsets for the balloon and the chase crew.

On their way east, as the balloon reached 28km, Paul and Matthew spotted it from the highway below. It was a starkly white dot among the orange clouds of sunset.

Meanwhile above, the cameras recorded moon rise over the ocean. The thick haze appeared in shadow in some places and slightly glowing orange in others. This combined to give a muddy brown view to the east.

The balloon burst at 31.6km (103,687 feet). A large portion of the top of the latex cell survived in one piece, while the cell neck blew into small pieces. On-board video also showed a rather calm descent into darkness.

Tim waited in the landing area. He was unable to receive direct APRS data, but Habhub provided three possible landing prediction. Two of these were computed by Habhub based upon national weather data and the two trackers. One was computed by the on-board Pi, based upon ascent history. This on-board data relayed into the Habhub map as a big red "X". The predicted areas zigged and zagged around eastern NC but finally started to converge on Tim's location just east of Tarboro.

Tim traveled the nearby country roads while Paul and Matthew still approached from Rocky Mount on US-64. It was now dark, but a HUGE orange full moon loomed out of the trees.

Matthew was first in spotting the payload's strobe several kilometers away. A last minute zag brought it closer to US-64 than the country roads. The team decided to meet up on the side of US-64 as the access to the landing area was easiest there. The payload came to rest in a cleared field about 100m from US-64. Tim hopped out to the field and recovered the payload. Later they all joined up at a Waffle House to enjoy looking at the results.