GPSL Launch

We'll be attending the Great Plains Super Launch  (GPSL) conference being held in Nampa, Idaho.  We will launch a 1200g exempt balloon and a pico balloon.  Our 1200g launch will be part of the mass launch associated with GPSL.  The pico balloon launch will most likely not occur with the mass launch due to the need for an indoor inflation of the balloon.

At GPSL EOSS plans to launch a Pico Balloon, attempting an around-the-world flight. The balloons used will be two 36-inch mylar party balloons tied together and filled to achieve superpressure and float at about 40,000 feet. This should be above most thunderstorms. The balloon will carry a solar-powered WB8ELK Skytracker beacon, weighing 15 grams. The beacon transmits on 20 meters (14.097 MHz) at 20 mW using the Weak Signal Propagation Reporter (WSPR) protocol. The signal will be picked up by amateurs throughout the world monitoring WSPR frequencies and posted to the WSPRnet server. From there, a program running on a local computer will read the WSPR packets, reformat the information and post it on the APRS servers. The balloon can be monitored on WSPRnet as KCØRPS and on APRS.FI or FINDU as KCØRPS-11.

A clever scheme using two WSPR packets is needed to report the necessary information. This includes location (6-character Maidenhead locator) within one mile, altitude within 200 feet, temperature within 5 degrees, GPS satellite status, and the solar panel voltage. All of this information is reported in the APRS packet. The beacon transmits every 10 minutes during daylight hours and goes dead at night.

Pictures of the balloon, beacon, and link to a video are available at:

Flight Coordinator: 
Event Date: 
Saturday, June 16, 2018 (All day)
Alt Launch Date: 
Sunday, June 17, 2018
Best Western Motel in Nampa as reference point.

Preflight Net:

  • Eyeball net after tech session on Friday

Recovery Operations: 

  • 146.100 MHz Balloon Field Simplex
  • 146.550 MHz Backup field simplex


Launch Site Simplex: 446.050 MHz

HF - Possible ops: 7.235 LSB

TR Breakfast: 
Breakfast at motel before we leave for the launch site.
Tactical Calls: 
TacticalCall SignNameNotes