EOSS-383 NDIA Flight - Recap

KCØRPS's picture
Submitted by KCØRPS on Thu, 08/21/2025 - 11:35

(Draft of flight summary)

EOSS-383 was launched at 7:25 a.m.on Saturday, October 17, 2025 from the Limon Softball Complex and achieved an altitude of 96,548 feet before cutdown and release of the parachute which brought the payload safely to rest at 09:48 AM in far eastern Cheyenne County near the intersection of CO State Hwy 385 and  County Road Y (38.9233333,-102.3451667).

Two tracking teams (Alpha: Jim KC0RPS. Nancy K0NKK, and  Bravo: Chris KB0BYZ) located the payload on state land.  Beacons and student experiments were undamaged. Video from two cameras on the flight will be posted soon. 

EOSS member mileage reimbursement submission here   

Recap Gallery: 
Original Announcement: 

This is one 1500g balloon carrying two student payloads, sponsored by the Rocky Mountain Chapter of the National Defense Industrial Association. We are launching from the  Limon Softball Fields at 7:10 a.m.  

Predictions are shown at www.eoss.org/predict. Scroll to the correct date and launch site. Two weeks before the flight, predictions will start updating on a 24-hour basis.

Event Date: 
Saturday, October 18, 2025 - 00:00 to 23:45
Flight Coordinator: 
Doug Leber NØMM
Launch Site: 
Limon Softball Fields
Flights: 

EOSS-383

Balloon Type: 
Kaymont 1500g Latex
Parachute: 
12 Ft Rocketman. Release Baker
Beacons: 
FrequencyCallsignTypeNotes
144.905KC0D-1APRS/ DF/Remote ReleaseTOP
144.340AE0SS-3APRS/DIGIBOTTOM Alias "AEØSS" Time slot 0:20 and 0:50
Payload Plan: 
PDF icon EOSS-383 Lite Rev B.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

SkyHub Link system has linked repeaters for our use during balloon flights:

  • Cedar Point (Limon) 447.650(-) MHz, 103.5 Hz
  • Hugo 447.150(-) MHz, 103.5 Hz
  • First View 447.600(-) MHz, 103.5 Hz (on Hwy 40, halfway between Kit Carson & Cheyenne Wells.


        Simplex Frequencies:
        • 446.100 MHz Balloon #1 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):

  • Rocky Mountain Wide Network – Talk Group 700 - Rocky Mountain Ham Radio has approval to the use "Wide" for flight operations.

        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
  • 144.905
Tactical Calls: 
TacticalCall SignNameNotes
AlphaKC0RPSJim LangstedNancy Koos K0NKK
BravoKB0YRZChris Krengel
CharlieKF0NLQAnne HerringtonNorm Black, KE0PAM, Doug N0MM , and John Lewis