EOSSP-3/4 Pico Balloon Launch at HAMCON 2025 - Recap

KCØRPS's picture
Submitted by KCØRPS on Sun, 10/19/2025 - 15:28

Monitor all three EOSS pico balloons here. Unfortunately, as of 11/17, we have not heard from EOSSP-2 or EOSSP-4 for 5 days and 3 days, respectively. The fact that they were relatively close together and floating at 43kft suggests that they might have encountered the same weather system and were taken down. But, EOSSP-3 disappeared for seven days, then reappeared, so there's always hope.

EOSS launched two pico balloons on October 25, 2025 from HAMCON 2025 in Grand Junction, Colorado.

EOSSP-3

  • Launch: 10/25/2025 10:28 am MDT (39.111921, -108.543315)
  • Circumnavigation #1: 11/6/2025 17:45 MST (12 days)

EOSSP-4

  • Launch: 10/25/2025 11:08 am MDT (39.111921, -108.543315)
  • Circumnavigation #1: 11/12/2025 21:41 MST (19 days)
  • Circumnavigation #2: 11/25/2025 17:52 MST (13 days)
Recap Gallery: 
Original Announcement: 

This is a demonstration launch at HAMCON 2025 in Grand Junction, Colorado of:

  • one 20m pico balloon, EOSSP-3
  • one 2m pico balloon, EOSSP-4
Event Date: 
Saturday, October 25, 2025 - 00:00 to 23:45
Flight Coordinator: 
KCØRPS
Launch Site: 
Grand Junction Colorado
Flights: 

EOSSP-4

This will be a 2m pico balloon

Balloon Type: 
SBS-13
Parachute: 
none
Beacons: 
Beacons
FrequencyCallsignTypeNotes
144.390 MHzAEØSS-9SkyTrackeralso on 144.340 MHz
Payload Plan: 
PDF icon EOSSP-4 Rev A.pdf

EOSSP-3

This is a 20m WSPR pico balloon

Balloon Type: 
SBS-13
Parachute: 
none
Beacons: 
beacons
FrequencyCallsignTypeNotes
14.0956AEØSSSkyTrackerWSPR --> APRS (as EOSSP-3)
Payload Plan: 
PDF icon EOSSP-3 Rev B.pdf
Tactical Calls: 
TacticalCall SignNameNotes