Embedded Files
Stations along the Appalachian Trail that were received during the balloon flight.
230-680km distant!
Jim had been helping with the Appalachian Trail Golden Packet over the past few years and wanted to try a packet radio digipeater from altitude for this year's event. So, Jim and Paul flew NSL-95 on the morning of July 19, 2025.
The top payload on the flight was a small box with Jim's AVRT9 APRS iGate/Digi/Tracker device. It was programmed to repeat the ATGP traffic onto another frequency that could then be iGated (put on the Internet) from the ground. A simple 1/4 wave ground plane antenna pointed down with small foam spars to hold the ground wires.
About 7m below box that was Paul's payload box with:
Pi-in-the-sky system (Raspberry Pi zero with camera, LoRa transceiver, and 1/4 wave ground plane antenna -- again pointing down, several AA lithium cells.)
Mobius Mini camera with small power bank
AP510 APRS tracker
Foam 'wing' like in previous flights to help reduce spin
Payloads, parachute and such totaled just under 800g. It was lifted by a 600g cell with ~1800g neck lift of H2.
Testing buoyancy using 1800g of weight on the balloon's neck.
During July/August we often find that flights land near the launch sites, and predictions for this flight were no different. Paul chose to fly out of southern Wake County in hopes of landing in the many fields in that area. <snicker>
Flight prediction from that morning
The Pi-in-the-sky showed problems from the start. Although it passed integration testing, the GPS unit would not lock on to any satellites. And the LoRa transmissions were mostly CRC errors. During descent it even showed signs of being in a reboot cycle. Testing is still underway to determine if a failed battery cell was the cause of this problem.
So the Pi just ended up taking still images and recording them locally.
They launched from Old Honeycutt Road Park in Fuquay-Varina, NC.
Slide show from onboard Pi camera
Over Fuquay-Varina looking west towards Shearon Harris power plant.
Ascent image from Pi camera
Near burst image from Pi camera
The flight proceeded exactly as expected. Jim noted that the digipeater was working well. The AP510 was sending tracking information on 144.390MHz, but the Pi-in-the-sky was only sending "location unknown" telemetry and small pieces of imagery via 434.450MHz LoRa.
Burst ocurred at 102,049ft.
30km over Raleigh looking west
30km over Raleigh looking east. New River Inlet and Wilmington/Cape Fear are visible along the coast.
At burst, the lower payload tumbled; showing a glimpse of the shattered balloon and...
Jim's payload box (upper left) with antenna support struts.
Descending near Angier, NC
There are plenty of open fields in the landing area, but this flight ended up in the middle of a 4 acre plot of the tallest trees around. Jim and Paul spoke with the property owner and then ventured into the woods to find the payload. No recovery could be done that day, but Jim followed up the next day with a drone overflight.
The day after that, Tim, our savior with bow and arrow, ventured out to the woods with Paul and snagged the payload on the first shot!
View from the video camera from 20m up a tree. Paul far below in upper center of image. "We're gonna need Tim to get this one"
Flight visualization
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