🎈 SP3RC PicoBalloon Missions

🛰️ Upcoming Mission: SP3RC-52 will use a transparent 60" balloon envelope. Transmission will include WSPR + DominoEX4 on the 10-meter band. More details coming soon.

📡 Current & Planned Flights – New Generation Trackers

# Callsign Launch Date Band TX Mode Telemetry Balloon PL (g) Last Signal Days Status Info Tracking
54 SP3RC-54 - 10 m WSPR + DominoEX4 SP3RC 60" transparent - - Scheduled -
53 SP3RC-53 2025-11-07 10 m WSPR + DominoEX4 SP3RC 60" transparent 6.08 g 2025-11-29 8 Flying -
52 SP3RC-52 2025-11-07 10 m WSPR + DominoEX4 SP3RC 60" transparent 6.18 g 2025-11-29 8 Flying -
51 SP3RC-51 2025-07-30 10 m WSPR + DominoEX4 SP3RC 60" transparent 6.03 g 2025-09-12 Lost -
50 SP3RC-50 2025-07-01 10 m WSPR + DominoEX4 SP3RC 50" transparent 6.07 g 2025-07-11 8 Lost
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PCB v16 - The launch took place in the evening. An attempt to record it with a drone was unsuccessful. The balloon began drifting rather quickly and couldn’t be kept in the camera’s view. I will try to capture it during future launches. In the DominoEx4 frame, I am also sending the TCXO frequency correction value.
49 SP3RC-49 2025-06-30 10 m WSPR + DominoEX4 SP3RC 50" transparent 6.36 g 2025-07-05 4 Lost
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PCB v16 - The launch was successful, but unfortunately air entered the balloon during the hydrogen transfer, so the cruise altitude is only about 8 200 m. A TCXO calibration using the GPS 1 PPS signal has been implemented. It works correctly, but still requires some fine-tuning.
48 SP3RC-48 2025-06-20 10 m WSPR + DominoEX4 SP3RC 50" transparent 27.67 g 2025-06-21 1 Lost
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PCB v16 - LiFePo4 battery test. Temperature sensor was attached directly to the battery. Transmitted after sunset, but shut down at -20°C. Operated normally the next day, but flew low — only ~9700 m, the weight had an impact. Stopped transmitting below 20° solar elevation, indicating the battery wasn't working effectively. Did not wake up the following day.
47 SP3RC-47 2025-06-03 10 m WSPR + DominoEX4 SP3RC 50" silver 6.64 g 2025-07-05 31 Lost
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PCB v15 - First flight using the DS18B20 temperature sensor. Seems to work well, but should be insulated. New telemetry format allows for collecting more precise data. After each WSPR transmission, one DominoEX4 frame is sent with accurate location and additional telemetry.
Legend: Row highlighted in green indicates a balloon that has completed at least one full circumnavigation of the Earth. 🌍

🕰️ Archived Flights – Older Generation Trackers

# Callsign Launch Date Band TX Mode Telemetry Balloon PL (g) Last Signal Days Status Info Tracking
46 SP3RC-46 2025-05-20 10m WSPR + DominoEX4 SP3RC β 50" silver 6.37 2025-06-12 23 Lost
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DIY PCB v15 Transmits 3 DominoEX4 frames after each WSPR frame. Performs flawlessly from launch, transmissions work perfectly! Processor temperature is inaccurate — time to add an external sensor. On the first day, TCXO was stable, though there was some fluctuation during ascent.
45 SP3RC-45 2025-05-09 10m WSPR + RTTY SP3RC α 50" silver 6.46 2025-05-15 6 Lost
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DIY PCB v15 Transmits 5 RTTY frames after each WSPR frame.
44 SP3RC-44 2025-04-26 10m WSPR SP3RC α 50" transparent 6.5 2025-06-06 0 Lost
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DIY PCB v15 New telemetry encoding (custom-made).
43 SP3RC/3 2025-04-02 10m WSPR ZachTek 50" silver 6.15 2025-05-05 33 Lost
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DIY PCB v13 No WDT in the MCU, software reset used, self-supporting PVs, HYDROGEN from PEM! Transmitting beautifully from launch, TPL reset works at first, but halfway through day two it stops resetting the MCU! Noticed the DONE pin is floating—this might be the cause.
42 SP3RC/2 2025-03-19 10m WSPR ZachTek 50" silver 8.59 2025-03-23 4 Lost
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DIY PCB v13 Transmits beautifully from launch, but the TCXO needs replacement—huge drift! Then a 3-day transmission gap—something’s not right.
41 SP3RC/1 2025-03-10 10m WSPR ZachTek 50" silver 7.69 2025-04-21 42 Lost
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DIY PCB v13 Transmits immediately after launch until the end of the day. Does not transmit regularly.
40 SP3RC/40 2025-03-06 10m WSPR ZachTek 50" silver 7.74 2025-04-12 37 Lost
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DIY PCB v13 Transmitted immediately after launch until the end of the day. Didn’t wake up after the night.
39 SP3RC/39 2024-11-02 20m WSPR ZachTek 32" transparent 7.89 NaT - Lost
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DIY PCB v11 6x PV vertically + diode and magnet! MCU running at 1 MHz! Launched in the evening after dark. High humidity in the air. Never transmitted.
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38 SP3RC/38 2024-10-25 20m WSPR ZachTek 50" transparent 5.1 2024-11-11 17 Lost
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DIY PCB v10
37 SP3RC/37 2024-10-20 20m WSPR ZachTek 32" transparent 5.17 2024-11-05 16 Lost
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DIY PCB v10
36 SP3RC/36 2024-10-08 20m WSPR ZachTek 50" transparent 14.78 2025-01-18 102 Lost
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DIY PCB v7 First circumnavigation of the Earth on October 22nd, after 14 days of flight! Second lap on November 5th, another 14 days later! Third lap on November 14th, just 9 days later!!! 3x6x PV vertically in triangle + REG170! MCU running at 2 MHz (16 MHz crystal with 8 pF capacitors).
35 SP3RC/35 2024-10-08 20m WSPR ZachTek 32" transparent 5.34 2024-10-24 16 Lost
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DIY PCB v8 6x self-supporting PV + REG170! MCU running at 2 MHz (16 MHz crystal without capacitors).
34 SP3RC/34 2024-09-20 20m WSPR ZachTek 32" transparent 5.62 2025-02-01 134 Lost
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DIY PCB v6 Started transmitting after 2 days — fully tested on the ground. Still something's off...
33 SP3RC/33 2024-09-18 20m WSPR ZachTek 32" transparent 5.83 2024-09-22 4 Lost
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DIY PCB v6 Started transmitting after 3 days — worked on the ground, but not in the air...
32 SP3RC/32 2024-09-17 20m WSPR ZachTek 50" transparent 5.96 2024-12-08 82 Lost
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DIY PCB v6 0.035 mm molybdenum antenna. First signal received after 36 days! (No transmission detected right after launch.)
31 SP3RC/31 2024-09-17 20m WSPR ZachTek 50" transparent 5.53 2025-05-12 237 Lost
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DIY PCB v5 0.035 mm molybdenum antenna. First signal received after 60 days! (No transmission detected right after launch.)
30 SP3RC/30 2024-09-06 20m WSPR ZachTek 50" transparent 5.25 2024-09-10 4 Lost
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DIY PCB v4 First signal received only above 12 km. GPS has trouble getting a fix when transmitting from both Si5351 output pins.
29 SP3RC/29 2024-09-04 20m WSPR ZachTek 50" transparent 5.25 NaT - Lost
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DIY PCB v4
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28 SP3RC/27 2024-08-30 20m WSPR ZachTek 50" transparent - 2024-12-21 113 Lost
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DIY PCB v4 First signal received after 7 days, then again after 6 more days, and once more after another 9 days. Likely no GPS fix due to TCXO interference.
27 SP3RC/26 2024-08-29 20m WSPR ZachTek 50" transparent 5.43 2024-09-10 12 Lost
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DIY PCB v4 Weak TCXO with significant drift, but still transmitted while riding 230 km/h winds! Flew past Atlanta and splashed down in the Atlantic off the U.S. East Coast.
26 SP3RC/25 2024-08-27 20m WSPR ZachTek 50" transparent 4.62 2024-09-02 6 Lost
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DIY PCB v3 First WSPR frame received only at 12 km altitude, then after several days. Transmission confirmed, but decoding issues. Needs an external crystal.
25 SP3RC/15 2024-08-24 20m WSPR ZachTek 32" transparent 4.46 2024-11-06 74 Lost
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DIY PCB v3 My first circumnavigation of the Earth! September 12, after 19 days of flight! Second circumnavigation probably on October 1, after 37 days aloft! (18 days for the second lap) Third circumnavigation probably on October 17, after 53 days aloft! (16 days for the third lap) Minor drift, good TCXO, but noisy and causing issues with GPS fix.
24 SP3RC/14 2024-08-24 20m WSPR ZachTek 32" transparent - NaT - Lost
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DIY PCB v3 Too strong wind, got stuck in a tree.
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23 SP3RC/13 2024-08-20 20m WSPR ZachTek 32" transparent 5.31 2024-08-22 2 Lost
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DIY PCB v3 5×39×19 PV panels, new WSPR setup, GPS time synchronization every frame, BOD 2.7 V + WDT, 0.1 mm main antenna + 0.06 mm braid.
22 SP3RC/12 2024-08-14 20m WSPR ZachTek 32" transparent - 2024-08-18 4 Lost
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DIY PCB v3 5x52×19 PV panels mounted flat with a crossbar, 0.1 mm main antenna + 0.06 mm braid. Launched in strong wind.
21 SP3RC/11 2024-08-13 20m WSPR ZachTek 32" transparent - 2024-08-26 13 Lost
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DIY PCB v3
20 SP3RC/10 2024-08-12 20m WSPR ZachTek 32" transparent 6.95 2024-08-24 12 Lost
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DIY PCB v3
19 SP3RC/9 2024-08-10 20m WSPR ZachTek 32" transparent - 2024-08-10 0 Lost
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DIY PCB v3
18 SP3RC/8 2024-08-07 20m WSPR ZachTek 32" transparent - 2024-08-16 9 Lost
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DIY PCB v1 Landed in Alaska. Longest and farthest flight so far — 55% around the globe. 🙂
17 SP3RC/7 2024-08-07 20m WSPR ZachTek 32" transparent - 2024-08-10 3 Lost
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DIY PCB v1
16 SP3RC/6 2024-08-06 20m WSPR ZachTek 32" transparent - 2024-08-09 3 Lost
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DIY PCB v1
15 SP3RC/5 2024-08-06 20m WSPR ZachTek 32" transparent - 2024-08-06 0 Lost
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DIY PCB v1 First tracker without GPS-based calibration — TCXO only. Finally achieved stable operation. Reached 8,600 m, then started descending. Likely a leak in the balloon envelope.
14 SP3RC/4 2024-07-31 20m WSPR ZachTek 32" transparent 8.2 2024-08-05 5 Lost
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DIY PCB v1 Solar panel mounted on a toothpick.
13 SP3RC/3 2024-07-30 20m WSPR ZachTek 32" transparent - 2024-07-31 1 Lost
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DIY PCB v1
12 SP3RC/2 2024-07-30 20m WSPR ZachTek 32" transparent - 2024-08-01 2 Lost
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DIY PCB v1
11 SP3RC/1 2024-07-28 20m WSPR ZachTek Big Star transp. - 2024-07-30 2 Lost
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DIY PCB v1 Red Star balloon with removed envelope coating. Crashed somewhere in Russia. Botched WSPR frequency synchronization with GPS — most frames were out of band.
10 SP3RC 2024-07-25 20m WSPR WB8ELK 32" silver - 2024-07-26 1 Lost
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DIY PCB v1
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9 SP3RC 2024-07-21 20m WSPR WB8ELK 2 x 32" silver - NaT - Lost
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Arduino NANO (bare chip) + Si5351 + GPS NEO-6M, powered by 5 × 52×19 mm solar panels. Balloon climbed to 9,500 m and began drifting slowly. Went silent around 18:00 — woke up the next day over Hungary!
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8 SP3RC 2024-07-20 20m WSPR WB8ELK 2 x 32" silver - NaT - Lost
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Custom PCB v1 (my design) + ATmega328PB + Si5351 + GPS NEO-6M, powered by 6 × 52×19 mm solar panels. Balloon reached 11,000 m and drifted nicely. Last telemetry frame around 18:00. Did not wake up the next day.
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7 SP3RC 2024-07-19 20m WSPR WB8ELK 2 x 32" silver - NaT - Lost
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Custom PCB v1 (my design) + ATmega328PB + Si5351 + GPS NEO-6M, powered by 6 × 52×19 mm solar panels. Total failure — crashed into a spruce tree during launch.
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6 SP3RC 2024-07-18 20m WSPR WB8ELK 32" silver - 2024-07-18 0 Lost
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No info.
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5 SP3RC 2024-07-15 20m WSPR WB8ELK 32" silver - NaT - Lost
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Arduino NANO (bare chip) + Si5351 + GPS NEO-6M, powered by 6 × 52×19 mm solar panels. New H2 generator with dryer. Did not transmit — antenna ripped off by pigeons!
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4 SP3RC 2024-07-08 20m QRSS DFCW - 32" silver - 2024-07-08 0 Lost
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Arduino NANO (bare chip, all other components removed) + BMP280 + Si5351, powered by 6 × 52×19 mm solar panels.
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3 SP3RC 2024-07-03 20m QRSS DFCW - 1m latex - 2024-07-03 0 Lost
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Arduino NANO (bare chip, all other components removed) + BMP280 + Si5351, powered by 6 × 52×19 mm solar panels. Max altitude: 12,100 m, min temperature: –20°C
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2 SP3RC 2024-07-01 20m QRSS DFCW - 1m latex - 2024-07-01 0 Lost
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Arduino NANO + BMP280 + Si5351 + 5V step-up converter + 3.7V 1000mAh LiPo battery. Max altitude: 12,400 m, min temperature: –28°C
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1 SP3RC 2024-06-08 20m QRSS DFCW - 1m latex - 2024-06-08 0 Lost
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Arduino NANO + BMP280 + Si5351 + 5V step-up converter + 2 × 3.7V 250mAh LiPo batteries in parallel. Max altitude: 9300 m, min temperature: –28°C
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