EOSS-405 Colorado Space Grant Consortium Summer Flight - Recap

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Submitted by KCØRPS on Sat, 07/25/2026 - 17:14

Saturday, August 22, at 6:55 a.m., EOSS launched EOSS-405 a 3,000 g balloon with 8 payloads from students participating in the Colorado Space Grant Consortium program. This summer's students were from Arapahoe Community College, CU Boulder, CU Colorado Springs, and Pikes Peak. The launch site was the Limon Softball Field. The balloon ascended to an elevation of 107,526 ft (Close to a record!), landing south of Limon, CO, about 1mile west of Highway 71. The crossroads were N/S CR201 and E/W CR34.Students started arriving at the Limon Softball in Limon, CO at 4:30 am. The students did a final check of their payloads, sealed them, and did a final weight; by 5:30, the payloads were being strung on the flight line.  It was a beautiful Saturday morning with no wind; thus, the students with their payloads were in a "U" shape on the softball field, allowing the balloon to go straight up. Straight up it did go. Summer winds tend to circle east then west with minimal north/south movement.  The landing site was a short 17 miles from the launch site. The trackers were at the intended landing, while the students were able to watch the balloon reach 107,526 ft. Most saw it burst with the white puff of powder. The trackers had the students head for the predicted landing,  where they saw the parachute coming down.  A quick modification in our location allowed them to see the landing.  Trackers had already contacted the landowner. She agreed to come out on her ATV to help retrieve.  She drove an EOSS member out to the landing site and returned with the payloads.  The hike out and back would have been about 2.4 miles, sometimes through very muddy areas. While waiting at the softball field, the Limon Police stopped to see what we were doing, and then a Sheriff's Officer stopped.  Both officers were intrigued with the launch activities. They also offered any assistance we may need today or at future launches.EOSS members submit mileage for reimbursement here.

Recap Gallery: 
Original Announcement: 

NOTICE: FLIGHT HAS BEEN POSTPONED ONE WEEK TO 8/22  LAUNCH SITE IS DEFINATELY LIMON 

This will be one 3000g balloon, or ONE 1500g balloons carrying student payloads from participating schools througout Colorado.

Event Date: 
Saturday, August 22, 2026 - 00:00 to 23:45
Flight Coordinator: 
KØNKK
Launch Site: 
Limon Softball Fields
Flights: 

EOSS 405H

Balloon Type: 
Totex 3000g Latex
Parachute: 
12FT ROCKEMAN
Beacons: 
FrequencyCallsignTypeNotes
145.645 MHzKCØD-2Remote Release/DFTOP, Secondary Beacon
1090 MhzN991SSADS-BSquawk: 4453
144.340 MHzKØSCC-13APRS/Digi EOSSGBOTTOM beacon, timeslotted :00 & :30
Payload Plan: 
PDF icon EOSS-405 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 at Mount Mestaa'ehehe 

        • 447.650 MHz (-5 MHz Offset, No Tone) Skyhub Link repeater at Cedar Point

 

 

       • 447.150 MHz (-5 MHz Offset, No Tone) Skyhub Link repeater at Hugo

        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
AlphaW9CNMike PappasT&R Coordinator
BravoN/AChris KrengelNot Available
CharlieKCØRPSJim LangstedTrack & Recovery†
DeltaKØSCCStephen MeerFlight String, T & R
EchoNØMMDoug Leber Balloon T & R
FoxtrotKØNKKNancy KoosFlight Coordinator
GolfKEØUWCGlenn RekerGround Station
HotelKF0NLQAnne HerringtonBalloon, T & R
JulietN/AJohn SpainhowerNot Available
KiloWØMLStephen Williams, MicheleFlight String, T & R
TangoKFØYMLJohn LewisBalloon Fill, T&R
YankeeKEØYALBrad MearsT & R
TR Breakfast: 
Limon IHOP 6:00AM