EOSS-302 NDIA STEM Flight - Recap

The balloon was launched at 0819 and reached an altitude of 110,331 ft MSL at  09:41 when  the balloon burst It was recovered near Karval, Colorado at GPS Coordinates:38.77888, -103.39334

mileage link for 2020 flights is here 

Original Announcement: 

10/2/2020 We are Go for a Saturday Morning Launch at 0830

Please read the change notes in red below

10/1/2020 Payload Plan Rev D has been posted. This is an exempt flight

One 3000g 3000g balloon sponsored by the Rocky Mountain Chapter of the National Defense Industrial Associaiton, carrying student experiments from multiple schools from:

  • Colorado
  • Texas
  • Pennsylvania

Note: we have changed to a 3000g balloon for more altitude. Flight predictions can be found here. EOSS-302 is for a 1500g balloon, EOSS-702 (see link in upper right) is for the 3000g balloon

Event Date: 
Saturday, October 3, 2020 (All day)
Flight Coordinator: 
Launch Site: 
Punkin Center: X=60, Y=40 Test: N39.000 W104.00 Ans: X=44.0 y=50.2



Balloon Type: 
Totex 3000g Latex
10' Rocketman with wireless release
145.645 MHzKCØD-14Remote Release / DFSecondary Beacon
144.340 MHzAEØSS-12APRS / Digi EOSSAPrimary Beacon, Timeslotted 0:27 and 0:57
Payload Plan: 

Flight-Specific Communications Plan

Note that the pre-flight net has been perminently changed to 7pm (that's 1900 MDT (0100Z)).

EOSS Preflight Net @ 7 PM MDT preceding night:
        • 449.225 MHz (-5 MHz Offset, 141.3 Hz Tone )  RMHAM, connected to the Fun Machine linked system 
        • 146.940 MHz (-600 KHz Offset, 103.5 Hz Tone) RMRL Repeater if the RMHAM machine is down
        • 146.640 MHz (-600 KHz Offset, 100.0 Hz Tone) DRL Repeater will serve as a backup to the backup repeater 

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)

Note: A statewide ARES exercise will occur on the same day as this flight (Saturday) and will be using the RMHAM DMR system. EOSS will be secondary to this exercise and should minimize use to flight-critical communications.

DMR Communications:

  • This flight will use RMHAM's Rocky Mountain Wide talk group on whatever repeater you can hit. Please see the note above.

Track & Recovery Operations:
             • 448.450 MHz (-5 MHz Offset, 100.0 Hz Tone) PPFMA repeater.

        Simplex Frequencies:
        • 446.100 MHz Balloon T&R Simplex 
        • 446.150 MHz Optional T&R Simplex        • 446.150 MHz Spare T&R Simplex

        • 446.275 MHz Car to Car drive out Simplex (potential interference with low-power YSF Fusion Node in Colorado Springs)
        (Note that some radios assume these are repeater frequencies and attempt to put a 5 MHz offset in the transmit frequency automatically)

        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 primary beacon
  • 145.645 secondary beacon
  • 144.905 beacon under test


Tactical Calls: 
TacticalCall SignNameNotes
AlphaWA0GEH. KC0DMarty. Mark
BravoW9CN, N0JPSMike, John
CharlieKC0RPS, W0GVJim Flight Controller, Gerry
GolfK0JWB, K)NKKJohn, Nancy
Ground StationN2XGL,K5JKJeff, Tom, Randy
TangoKC0LJohn from Texas, IRLP
YankeeKE0YALBrad and Teri
IndiaN6BAJeff D.
TR Breakfast: 
Breakfest: I-Hop in Limon, 7:15 Predict: 11 mi NW of Arlington (NS CR-2 & EW CR-AA) (X 72.0 Y 13.5) Weather forecast for Deer Trail at 0800 MDT Saturday: Clear skies, cloud cover 30%, visibility unlimited Temperature 45, dew point 35, wind NW at 8 mph