Pico Balloon

Pico Balloon Serial #8 – Full Flight Synopsis
Mission: High-altitude pico balloon experiment
Balloon Call Sign: K5RGV-8
Launch Date: July 30, 2025 (around noon local time)
Launch Location: Just southwest of Harlingen, Texas (Grid: EL06), near the Rio Grande
Builder: WT5TX
Organization: Rio Amateur Radio Club (K5RGV)
Balloon Type: Foil/plastic, approximate size of a large beach ball
Frequency: 17 meters WSPR
Tracking Platforms: WSPRnet

Flight Summary (as of August 3, 2025, 11:24 AM local time)

Metric Value

Total Time Aloft 5 full nights, entering Day 6
Approximate Distance Traveled ~1,400+ miles (est.)
Current Altitude ~40,755 feet
Average Speed 10–20 mph (depending on conditions)
Voltage Range Observed 4.65 V – 4.95 V
Temperature Range Observed -5°F to -9°F
Highest Receiver Count 42 ground stations (peak observed)
Current Position Grid DL42vm (~869 miles SW of Harlingen, TX)
Current Heading West, over the Pacific Ocean

Flight Phases

Day 1 (July 30) – Launch & Initial Ascent
Launched into mostly clear skies with low surface winds.
Rapid climb to float altitude of ~40,000 ft.
Initial reports received within the first few hours.
Excellent solar charge performance on Day 1 (voltage ~4.9+ V).
Days 2–3 (July 31–Aug 1) – Gulf of Mexico & Mexican Coast
Crossed the Gulf at a consistent altitude and speed.
Maintained reliable telemetry during daylight; likely powered down at night, resumed at sunrise.
Tracked by dozens of iGates across the southern U.S. and eastern Mexico.
Continued a clean western path into northwestern Mexico.
Day 4–5 (Aug 2–3) – Baja Region & Pacific Entry
Balloon passed over Baja California Sur.
By August 3, 11:24 AM local time, balloon was offshore, heading into the eastern Pacific.
Still transmitting reliably; altitude, power, and speed all stable.

System Health and Observations
System Status Notes

Altitude ✅ Stable ~40,700 ft Holding consistent float since Day 1
Battery ✅ Healthy 4.65–4.95 V Slight daily dip in AM; good recovery
Signal ✅ Consistent coverage Tracked by 30+ iGates per day
Weather ✅ No significant storms Has avoided major turbulence or downdrafts
Direction ✅ Westward drift intact Following expected high-altitude wind path

Overall Status:
Excellent.

Pico Balloon Serial #8 is operating exactly as intended. It has successfully floated over five full nights, maintained strong altitude and voltage, and continues west over the Pacific. Every system shows stability, with no anomalies or balloon deflation events observed.

On April 13, 2025, at 8:15 AM local time, the second Rio ARC Pico Balloon, sponsored by Tom (WT5TX), was launched southwest of Harlingen, TX, aiming to circumnavigate the globe and float for weeks. Track its journey here: watch here.

What is a Pico Balloon?

A pico balloon for ham radio is like a tiny, adventurous party balloon that decided to ditch the birthday bash for a wild ride in the stratosphere. Picture a shiny, helium-filled Mylar bag, no bigger than your average beach ball, stuffed with a whisper-light radio transmitter that's basically a hamster on a tech wheel, frantically beaming digital signals to ham radio nerds below. It’s got solar panels thinner than your patience during a Zoom call, sipping sunlight to keep it alive as long as there is sun on it. This plucky little floater bobs along at 30,000 to 40,000 feet, hitchhiking on jet streams, circling the globe while dodging storms and curious seagulls. It’s the ultimate "I’m outta here" move—part science experiment, part rebellious teen, broadcasting its location like a cosmic postcard until it pops or just ghosts the atmosphere.

Ok, the funny stuff is over, this is what it really is: A pico balloon ham radio is a small, lightweight balloon, often made of Mylar, that carries a tiny amateur radio transmitter as its payload. These balloons, typically 1-3 feet in diameter, are filled with hydrogen or helium to float at high altitudes, around 20,000 to 60,000 feet, in the stratosphere. The radio transmitter, weighing as little as 10-30 grams, is solar-powered and uses protocols like APRS (Automatic Packet Reporting System) or WSPR (Weak Signal Propagation Reporter) to send data such as position, altitude, and sometimes sensor readings (e.g., temperature or humidity) back to ground stations.

Ham radio operators launch pico balloons to experiment with long-distance communication, track global flight paths, and study atmospheric conditions. Due to their light weight and precise gas fill, these balloons can drift for days, months, or even years, sometimes circumnavigating the globe multiple times. The hobby combines physics, meteorology, and radio technology, and is popular among amateur radio enthusiasts for its low cost and scientific potential.