EOSS-370/371 Colorado Space Grant Consortium Spring Launch - Recap

KCØRPS's picture
Submitted by KCØRPS on Thu, 03/27/2025 - 09:58

Two 3000g non-exempt balloons were launched from Deer Trail Colorado on Sunday April 6, 2025 carrying student payloads for the Colorado Space Grant Consortium. The balloon flights proceeded as follows: 

  • EOSS-370 launched at 6:45am and reached an altitude of 93,767 feet. The balloon decended by parachute and landed southwest of Matheson, Colorado off of County Road 141 at 39.174833, -104.017167. The students hiked 1.1 mi in to the landing site to retrieve the payloads.
  • EOSS-371 launched at 7:21am and reached an altitude of 94,074 feet. The balloon decended by parachute and landed northeast of Matheson, Colorado, west of County Road 149 at 39.2358, -103.9987, 6021 feet. The students hiked 1.36 mi in to the landing site to retrieve the payloads.

 EOSS member mileage reimbursement submission here.

Recap Gallery: 
Original Announcement: 

The COGCG flight is scheduled to fly on Sunday April 6th.

Ground winds appear acceptable for a launch. Please see the posted payload plans for payload distribution and launch times. The updated prediction is available here (select correct date and launch site).

  • 04-05-2025Payload Plans Rev D posted
  • 04-04-2025Payload Plans Rev C posted
  • 03-30-2025Payload Plans Rev B posted
  • 04-01-2025Participation link (below) has been repaired

This is a two 3000g balloon or three 1500g balloons carrying student-built payloads from a variety of Colorado colleges participating in the Colorado Space Grant Consortium.

If clouds preclude flying non-exempt Heavy balloons, the payloads will be split into three exempt Lite balloons as follows:

Register here to indicate your participation in the Balloon Flight.

Look here to see who has registered.

Event Date: 
Sunday, April 6, 2025 - 00:00 to 23:45
Flight Coordinator: 
KCØRPS
Launch Site: 
Deer Trail
Flights: 

EOSS-370 Heavy

Carrying Colorado Space Grant Consortium student payloads

Balloon Type: 
Totex 3000g Latex
Parachute: 
12 ft Rocketman with Remote Release Charlie
Beacons: 
Beacons
FrequencyCallsignTypeNotes
145.710 MHzKC0D-3Remote Release/DFTOP, Secondary Beacon
144.340 MHzAE0SS-12APRS/Digi EOSSABOTTOM, Primary Beacon, TS 0:27 & 0:57
145.535 MHzAE0SS-4APRSFlight Qualification
Payload Plan: 
PDF icon EOSS-370 Heavy Rev D.pdf

EOSS-371 Heavy

Carrying Colorado Space Grant Consortium student payloads

Balloon Type: 
Totex 3000g Latex
Parachute: 
12 ft Rocketman with Remote Release Baker
Beacons: 
Beacons
FrequencyCallsignTypeNotes
144.905 MHzKC0D-1Remote Release/DFTOP, Secondary Beacon
144.340 MHzAE0SS-3APRS/Digi AEØSSBOTTOM, Primary Beacon, Timeslot 0:20 & 0:50
145.645 MHzKC0D-14APRSFlight Qualification
Payload Plan: 
PDF icon EOSS-371 Heavy Rev D.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
AlphaWAØGEH, NØKKKMarty Griffin, Nancy Koos
Beta
Charlie
DeltaKØSCC, NØJPSStephen Meer, John Spainhower
EchoKEØUWC, KFØMBRGlenn Reker, John Diubaldo
FoxtrotKCØRPSJim Langsted
Ground StationN2XGL, KBØTVJJeff Shykula, Russ Chadwick, Randy
Papa
YankeeKEØYALBrad Mears
HotelNØNDMLarry Noble
TR Breakfast: 
0600 at IHOP in Flying J truck stop in Limon