NSL-88

NSL-88 launched on Easter morning, April 4th, 2021.

Matthew L. saw the forecast for a beautiful day, and he wanted to fly. So he and Paul L. cobbled-together a flight. Ostensibly, this would test the behavior of an up-scaled NSL-87 wing design on a more massive payload. The flight train, left-over from NSL-80 & 81 consisted of:

An old 75cm parachute

Upper, small payload box with

• AP510 APRS tracker

Lower, large payload box with

• Inexpensive PowerAdd 360-degree camera (NSL-65)

• MobiusMini camera and USB battery pack

• Pi-in-the-sky setup from NSL-81 (433MHz LoRa, camera, temperature probes)

• A board of polystyrene foam "wing" (120cm x 10cm x 1cm)

The entire payload came to 810g. It was lifted by a 600g cell with 2000g neck lift from H₂.

The summer jet stream hadn't fully made it into the region, so they decided to launch again from Bray Park in Siler City. That would land their payload near the fields of Spivey's Corner, NC.

Payload prep that morning frustrated Paul L. The Pi-in-the-sky system had recently been rebuilt with the latest code and a replacement Pi camera in an attempt to fix camera failures. But this time, it was the LoRa transmitter that was stalling out. Twice during prep the transmitter fell quiet, and the payload had to be disassembled to fix. But after some fiddling, and much duct tape, it started again. So balloon fill began.

But moments after launch, the LoRa transmitter fell silent again. Maybe a short in the antenna wiring? So the flight only had one tracker, and no on-board landing prediction software. And even worse, HABHUB.ORG was seeing a 15 minute delay in processing APRS data. So it was back to chasing like in the "olden days".

The stock 360 camera just had enough battery for 90 minutes of use. And some of that was taken up by the issues before launch. That was okay though, it was primarily there to watch the wing behavior during ascent.

Part of the way into the flight, Jim N4WFP joined in on the chase. Two chase car were plotted on HABHUB, but again showing delays.

As the payload descended, the bottom box tipped up on its side due to the "wing". Paul expected that the thin foam would break, but it held for the entire flight.

The two chase cars headed past Spivey's Corner to the last 'gated' APRS packet. The LoRa was still silent, but after a few minutes, both Jim and Matthew were able to decode a nearby APRS packet. It landed in a fallow field just beside the road. Recovery doesn't get any better than that!