EOSSP-2 Pico Balloon Launch - Recap

KCØRPS's picture
Submitted by KCØRPS on Wed, 08/20/2025 - 16:59

This isn't really a Recap, because the pico balloon is still flying, as of February 4, 2026 (day 139) it has made ten circumnavigations of the world (see map in Charts & Data).

  • Launch: 9/18/2025 10:46 am MDT (40.108455, -104.702247)
  • Circumnavigation #1: 10/9/2025 2:00 am MDT (21 days)
  • Circumnavigation #2: 10/23/2025 7:17 am MDT (14 days)
  • Circumnavigation #3: 11/4/2025 12:30 am MST (12 days)
  • Circumnavigation #4: 11/17/2025 2:03 am MST (13 days) - estimated after no report for 9 days
  • Circumnavigation #5: 11/28/2025 7:00 pm MST (11 days)
  • Circumnavigation #6: 12/11/2025 8:42 pm MST (13 days) - estimated after no report for 12 days
  • Circumnavigation #7: 12/24/2025 3:22 am MST (12 days)
  • Circumnavigation #8: 01/08/2026 1:12 pm MST (15 days)
  • Circumnavigation #9: 01/20/2026 1:53 pm MST (12 days)
  • Circumnavigation #10 02/04/2026 12:05 pm MST (15 days)

20m WSPR SkyTracker v1, KCØRPS call sign, 60" Cymylar, pre-stretched to 0.5 psi for 2 hours, 70.75g balloon,15.58g payload, 5.75g free lift

Several EOSS members met at NØJPS' hanger on Thursday, September 18, 2025 at Platte Valley Airpart to prepare and launch our first pico balloon since 2018. After coffee and donuts, the 20m dipole antenna was assembled on the SkyTracker beacon and the pre-stretched balloon was inflated wtih hydrogen to exactly 21.33g of lift. The beacon was attached and the assembly carried out to the south side of the handers for launch. At 10:30 AM MDT the balloon was released. Because of the slow ascent of the balloon (1 meter/second) the antenna dragged in the grass and had to be released several times. Eventually the balloon rose sufficiently and continued upward. The balloon reached a float altitude of 45,000 ft in about 3-1/2 hours. 

The solar powered beacon can be monitored at https://amateur.sondehub.org or at www.aprs.fi/eossp-2 

Recap Gallery: 
Original Announcement: 

This will be our practice launch prior to HAMCON 2025. The launch will be from Platte Valley Airpart at 7507 Co Rd 39, Fort Lubton, CO 80621. We will meet at 9:00 am and plan to launch around 10:30 am. Please contact an EOSS member for onsite driving details.

Event Date: 
Thursday, September 18, 2025 - 09:00 to 11:00
Flight Coordinator: 
KCØRPS
Flights: 

EOSSP-2

This is the second pico balloon launched by Edge of Space Sciences. The intent is to circumnavigate the globe at approximately 45,000 ft. The solar-powered beacon transmits a 20m WSPR signal (during the day) that is encoded with location, altitude, and temperature information. It will be ported to APRS as EOSSP-2 and will be visible on www.aprs.fi/eossp-2 as well as https://amateur.sondehub.orgThe first EOSS pico balloon was launched on June 15, 2018 from the Great Plains Superlaunch event in Napa, Idaho. It flew approximately 12,000 miles and came down in a thunderstorm in the Bahama Islands.

Balloon Type: 
60" Cymylar balloon
Parachute: 
none
Beacons: 
Beacons
FrequencyCallsignTypeNotes
14.0956 MHzKCØRPSWB8ELk SkyTrackerWSPR --> APRS (as EOSSP-2)
Payload Plan: 
PDF icon EOSSP-2 Rev A.pdf
FrequencyList: 

There will be NO Preflight Net on the preceding night:

Flight Day:

Talk-in will be:

        • 449.450 MHz (-5 MHz Offset, 103.5 Hz Tone) RMRL repeater
  or
        • 446.100 MHz Balloon #1 Field Simplex 

Tactical Calls: 
TacticalCall SignNameNotes