EOSS-347 NDIA Flight - Recap

A single 1500g balloon was launched at 8:07 am MDT on October 21, 2023 from Deer Trail School carrying student expreiments from a variety of schools. The balloon reached a height of approximately 86,000 feet and landed south of Arickaree, Colorado.

Link for EOSS member mileage reimbursement


Original Announcement: 

One 1500g balloon carrying student payloads sponsored by NDIA

  • 10-5-2022Payload Plan Rev B posted
  • 10-17-2022Payload Plan Rev C posted
Event Date: 
Saturday, October 21, 2023 - 00:00 to 23:45
Flight Coordinator: 
Launch Site: 


This balloon will fly exempt and be cut down at 91 kft.

Balloon Type: 
Totex 1500g Latex
12 ft Rocketman with Remote Release Baker
145.645 MHzKC0D-1Remote Release/DFTOP beacon
145.535 MHzAE0SS-2APRS/DFFirmware Qualification
144.340 MHzAE0SS-13APRS/DigiBOTTOM beacon, timeslotted :10 & :40
Payload Plan: 

EOSS Preflight Net @ 7 PM Mountain Time the preceding night:
        •  449.225 MHz (-5 MHz Offset, 141.3 Hz CTCSS) Rocky Mountain Ham Radio (RMHAM) Repeater and EchoLink *CANONCTY* conference and the Fun Machine linked system
        • 146.940 MHz (-600 KHz Offset, 103.5 Hz CTCSS) Rocky Mountain Radio League (RMRL) Repeater if the RMHAM machine is down
        • 146.640 MHz (-600 KHz Offset, 100.0 Hz CTCSS) Denver Radio League (DRL) Repeater will serve as a backup to the backup repeater 

Flight Day:
Launch Site:
        • 446.050 MHz Simplex  
        (Note that some radios assume these are repeater frequencies and attempt to put a 5 MHz offset in the transmit frequency automatically)

Track & Recovery Operations:
        • 449.450 MHz (-5 MHz Offset, 103.5 Hz Tone) RMRL repeater

        Simplex Frequencies:
        • 446.100 MHz Balloon #1 Field Simplex 
        • 446.150 MHz Balloon #2 Field Simplex
        • 446.200 MHz Balloon #3 Field Simplex
        • 446.275 MHz Car to Car drive out Simplex
        (Note that some radios assume these are repeater frequencies and attempt to put a 5 MHz offset in the transmit frequency automatically)

Digital Mobile Radio (DMR):

The decision as to which talkgroup use will be made by the EOSS RF Coordinator on a per flight basis.

  • Rocky Mountain Wide Network – Talk Group 700 - Rocky Mountain Ham Radio has approval to the use "Wide" for flight operations.
  • Central Colorado Regional Network – Talk Group 720 - On occasion, EOSS may use the Central Colorado Regional Network (Talk Group 720).

        Legacy 2M Simplex Frequency (not generally used due to desense/interference issues with the 2M APRS packets)
        • 146.550 MHz Simplex

2M Direction Finding Frequencies:

  • 144.340
  • 144.360
  • 144.905
  • 145.535
  • 145.645
  • 145.710
  • 145.765


Tactical Calls: 
EOSS 347
TacticalCall SignNameNotes
AlphaWAØGEH, KØNKKMarty, Nancy
BravoKCØRPS, W0GVJim, GerryFlight Controller
CharlieNØRPF, KØBRARob, Doug
YankeeKE0YALBradWelcome Back
Ground StationN2XGL, N5JK, KB0TVJ, N0CALLJeff, Tom,Russ, Randy
TR Breakfast: 
Launch Time: 0800 MDT Optional Breakfast at I-Hop, Limon, 7:00