EOSS-295/296 CU Boulder Gateway to Space and DemoSats - Recap

See pictures and data posted below.

Two 3000g balloons were launched on Saturday, November 9, 2019 from Eaton Middle School. The EOSS-295 launched at 6:54am. EOSS-296 launched at 7:23am.


  • Launch:   13:42:56 UTC  40.5271490,-104.7237760            4880 Ft
  • Burst:      15:21:15 UTC   40.2072380,-103.6793790           104023 Ft
  • Landing:  15:56:18 UTC  40.0468610,-103.3350910           4767 Ft



  • Launch:   14:22:59 UTC   40.526547,-104.723456                4860 Ft
  • Burst:      15:55:54 UTC   40.226835,-103.533459                110842 Ft
  • Landing:  16:33:34 UTC  40.048112,-103.168691                  4626 Ft


EOSS members can apply for mileage at https://goo.gl/forms/V7r4DKZyEpod5auj1

Original Announcement: 

We are go for a Saturday launch from Eaton Middle School!  See you there.

The final payload plans have been posted. The predictions were updated at 5:00pm on Friday to match these payload plans.

Two 3000g balloons (or four 1500g balloons if the cloudcover is excessive)

The launch will most likely be Eaton Middle School. Information and maps are available here. If winds shift, there is a possibility that the launch site may have to be moved. Keep watching this website for updates. The predicted flight path is shown here. Scroll down to the correct launch site and click on the GIF file for a picture of the prediction. The prediction updates at approximately 11am each day.

To follow this flight, click on this link:  https://track.eoss.org

Additional tracking and observation data area available at http://wxqa.com/eoss295.html

If the cloudcover is greater than 5/10ths, the two Heavy balloons will be split into four 1500g Lite balloons, capable of flying through the cloudcover. The payload plans for these balloons are shown below:

Event Date: 
Saturday, November 9, 2019 - 00:00
Flight Coordinator: 
Launch Site: 
Last Chance X=50, Y=20 Test: N40.000 W103.000 Ans:X=81.3 Y=37.9

EOSS-295 Heavy

Balloon carrying Gateway to Space team payloads

Balloon Type: 
3000g Latex
12 foot Rocketman with wireless release Baker
144.905 MHzKC0D-2DF / Remote Releasesecondary beacon
144.340 MHzAE0SS-12APRS / Digi EOSSAprimary beacon, timeslotted at 0:27 and 0:57
Payload Plan: 

EOSS-296 Heavy

Balloon carrying Colorado Space Grant Consortium DemoSat payloads and C-BASE ADS-B beacon

Balloon Type: 
3000g Latex
12 foot Rocketman with wireless release Adam
145.645 MHzKC0D-1DF / Remote Releasesecondary beacon
144.340 MHzAEØSS-13APRS / Digi EOSSprimary beacon, timeslotted at 0:07 and 0:37
Payload Plan: 

EOSS Preflight Net @ 8 PM MDT preceding night:
        • 449.225 MHz (-5 MHz Offset, 141.3 Hz Tone )  RMHAM Repeater
        • 449.450 MHz (-600 KHz Offset, 103.5 Hz Tone)  RMRL Repeater
        • 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)

Track & Recovery Operations:
        • 449.450 MHz (-5 MHz Offset, 103.5 Hz Tone) RMRL repeater (Assuming we are flying out of Eaton).

       We are approved to use RMHAM DMR “Wide” and the mobile DMR repeater for EOSS 295/296.


       Simplex Frequencies:
        • 446.100 MHz Balloon #1 Field Simplex (EOSS #295)
        • 446.150 MHz Balloon #2 Field Simplex (EOSS #296)
        • 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)

        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
AlphaW9CN, KB0YRZMike, Chris, JenAlpha Team, Downrange 295
BravoWA0GEH, KC0DMarty, MarkAlpha Backup, Launch, Track 296
CharleyKC0RPS, W0NFWJim, GeorgeLaunch, Trackers 296
DeltaK0SCCStephenLaunch, Tracker 295
EchoKE7KCKTomFlight Coordinator, Launch, Tracker
FoxtrotN6BAJeffTracker, SDR Guru 296
GolfK0JWB, K0NKKJohn, NancyTrackers, Downrange296
Ground StationN2XGL, KB0TVJJeff, Russ, RandyGround Station, FAA
IndiaKE0GKIBernadetteCU, CU ADS-B Payload
WhiskeyKD0NRYChrisCU Space Grant 295/296
TangoKC0L, N0LPJohn, NickTrackers, Downrange 295
TR Breakfast: 
Breakfast at Limon IHOP at 5:30, leave at 6:15 or Brush McDonalds 6:30 Mike, W9CN will operate as Alpha for the first balloon and Marty will operate for the second balloon. Mark and Marty will NOT go to the ground station to support the payload string prep and balloon fill it is under control. Looks like clear skies.... Friday 24 hr Predict: 11 mi SE of Akron (EW CR-30 & NS CR-GG) (X=74.0 Y=38.0)