EOSS-388/389/390 Ranum Innovation, Golden HS, and Evergreen HS - Recap

Nancy Koos K0NKK's picture
Submitted by Nancy Koos K0NKK on Mon, 11/17/2025 - 21:25

Three 1500g Lite balloons were launched from Deer Trail on Saturday, December 6, 2025. The upper level winds were higher than expected and the real-time landing predictions were putting the balloons across the state line in Kansas. Ultimately the balloons did land in Colorado and were easily retrieved once landowner permission was obtained. The balloons performed as follows:

  • EOSS-388, Evergreen HS, max altitude: 76,670 ft
  • EOSS-389, Ranum Inovation Center, burst altitude 91,765 ft
  • EOSS-390, Golden HS, burst altitude 94,256 ft

EOSS member mileage reimbursement submission here

 

Recap Gallery: 
Original Announcement: 
  • 11-25-2025Launch location changed to Deer Trail Colorado (maps and details shown here)
  • 11-25-2025Payload Plans Rev B issuesd
  • 12-05-2025Payload Plans Rev C issuesd

Ranum Innovation Center, Golden High School, and Evergreen High School fall flight. Launch  Dec 6. Estimating one or two 3,000g balloons or three 1500g balloons.

EOSS member participation signup link. To view results.

If the cloud cover exceeds 5/10ths the payload strings will be divided into three Lite balloons and the optional payload mass will not be flown:

Event Date: 
Saturday, December 6, 2025 - 00:00 to 23:45
Flight Coordinator: 
KCØRPS & KØNKK
Launch Site: 
Deer Trail
Flights: 

EOSS-388 Heavy

Balloon Type: 
Totex 3000g Latex
Parachute: 
12 ft Rocketman with Remote Release Adam
Beacons: 
Beacons
FrequencyCallsignTypeNotes
145.645 MHzKCØD-3Remote Release/DFTOP Secondary Beacon
144.905 MHzKC0D-1APRS/DigiFlight qualification with Adam
144.340 MHzAE0SS-1APRS/Digi EOSSABOTTOM beacon, timeslotted :27 & :57
Payload Plan: 
PDF icon EOSS-388 Heavy Rev C.pdf

EOSS-389 Heavy

Balloon Type: 
Totex 3000g Latex
Parachute: 
12 ft Rocketman with Remote Release Baker
Beacons: 
FrequencyCallsignTypeNotes
145.535 MHzKC0D-14Remote Release/DFTOP Secondary Beacon
144.340 MHzAE0SS-3APRS/Digi AEØSSBOTTOM, Primary Beacon, Timeslot 0:20 & 0:50
Payload Plan: 
PDF icon EOSS-389 Heavy Rev C.pdf
FrequencyList: 

EOSS Preflight Net @ 7 PM Mountain Time the preceding night:

 

The preflight net is hosted on the Fun Machine linked system https://www.we0fun.com/  

EchoLink *CANONCTY* conference and on the TGIF DMR Network Node: 1997 Talkgroup 815

Denver area Frequencies: 

    • 449.225 MHz (-5 MHz Offset, 141.3 Hz CTCSS) Mt Thorodin
    • 448.150 MHz (-5 MHz Offset, 141.3 Hz CTCSS) DIA
    • 449.975 Mhz (-5 MHz Offset, 100 Hz CTCSS) Westcreek
    • 447.525 MHz (-5 MHz Offset, 146.2 Hz CTCSS) Devils Head   

Back up Pre Flight Net Frequincies

        • 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:
        Repeaters:
        • 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: 
TacticalCall SignNameNotes
AlphaKBØYRZ Chris Kringel
BrovoNØJDJeff Deaton
CharlieKCØRPS Jim Langsted
DeltaKØSCC N0JPSStephen Meer, John Spainhower, Zach no call sign
EchoNØMM Doug Leber
FoxtrotKØNKKNancy Koos
GolfKFØNQLAnne Herrington
YankeeKEØYALBrad Mears
TR Breakfast: 
Tracker Breakfast will be at 0600 at the IHOP in Limon