Balloon Serial #8: Launch- Harlingen, Texas (July 30, 2025 ) 19+ Days Aloft

Launch region: Harlingen, TX
Current location (as of 2025-08-19 16:24): Between Big Bend National Park and El Paso, heading back toward Mexico.
Flight duration: Over 19 days.
Altitude range: Mostly around 12,700–12,800 meters (≈41,700–41,900 ft).
Altitude stability: Very stable; minor fluctuations (0–4 m per minute, occasional -15 m/min). The balloon has been maintaining high altitude efficiently, indicating good helium fill and minimal venting.
Temperature: Ambient temperature at flight altitude ranges from -14°C to -8°C (≈6–18°F).

2. Speed and Direction
Ground speed: Between 55–68 kph (≈35–42 mph). GPS speed is very close to wind-influenced ground speed.
Distance covered: Significant movement over Texas toward Mexico, consistent with southwest trajectory.
Direction: Predominantly west to southwest, with minor deviations likely due to upper-atmosphere wind changes.

3. Power and Solar Data
Voltage: Steady around 4.40–4.65V, indicating the battery is holding charge well.
Solar angle: Ranging from 50–72 degrees, showing daily sun exposure is still effective.
Power source performance: No obvious signs of power degradation. The solar array is functioning normally, keeping the voltage stable.

4. Altitude Changes
The balloon is very stable, with AltChgMpm mostly 0–2 m/min, occasional small negative changes (-2 to -4 m/min).
Altitude in feet is consistently around 41,800–41,995 ft, which is excellent for a high-altitude balloon.

5. Environmental Observations
Temperature trends: Slight variations, mainly between -14°C to -8°C. No extreme dips, which suggests consistent stratospheric conditions.
Flight stability: No rapid altitude changes, indicating no turbulence or strong weather interference at this altitude.

6. Key Takeaways
The balloon is stable and healthy: Altitude, power, and solar performance are all within expected ranges.
Trajectory: Currently moving back toward Mexico, southwest of Big Bend. Previous eastward movement has reversed, likely due to shifting stratospheric wind patterns.
Flight longevity: Over 19 days airborne, which is excellent for a Pico balloon. Likely to continue for several more days if power and helium remain adequate.
No major anomalies: No sudden drops in altitude, battery voltage, or temperature extremes.

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.