Recap of EOSS-120

photo by Jim Langsted, KC0RPS

LAUNCH DATE: July 21th, 2007
LAUNCH TIME: 07:13 am MDT (13:13 UTC)
LAUNCH SITE: Crow Valley Park, Briggsdale, CO (directions)

Pre-flight Prediction and Actual Track

Predict vs. Actual

Blue = Actual Track
Green = Predicted Ascent Phase
Red = Predicted Descent Phase

Map made with MapPoint
Prediction made with Balloon Track


Predict vs. Actual

Green Track = Ascent
Red Track = Descent
Prediction and Actual tracks made with Balloon Track

Maps by Google Earth

Launch Site - Crow Valley Park
Launch Point: 40.64443� lat.   -104.33895� long.
Grid: X=25.28 Y=37.36
Ascent Rate: 1100 feet per minute
Descent Rate: 950 feet per minute
Altitude: 4840 feet
Predicted Landing Site
Landing Point: 40.71234� lat.  -104.59753� long.
Grid: X=11.7 Y=42.0
Altitude: 4500 feet
Flight Time: 123 Minutes
Bearing: 289.2� True
Range: 14.3 Mi.
Actual Landing Site
Landing Point: 40.70734� lat.  -104.69185� long.
Grid: X=6.8 Y=41.7
Bearing: 283.4� True
Range: 18.981 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 266.1� True
Range: 4.95 Mi.

Prediction History for EOSS-120 AVAILABLE HERE

EOSS Flight Day Frequencies:

Global Frequencies

EOSS-120 Balloon Frequencies

  • Beacon
  • APRS
    • 144.340 MHz
      • ID: AE�SS-11
      • DIGI: EOSS
      • Node: BALNOD
      • APRS Time Slotted Every 30 seconds at 0:00 and 0:30
      • Telemetry once a minute
        • power up at 58 seconds past the GPS minute to properly slot telemetry
      • Sample Data

Radio Coverage:

  • Green, you should be able to work the payload systems.

  • Red, is the border of the received signal. Red appears jittery because it is depicted topographically. Thus, the red dots on the eastern half of the map but well within the maximum distance show hilly terrain behind (east) which reception is not possible.

This is a generic 95,000 ft ASL coverage map for flights that depart from the vicinity of our launch site. Flight day coverage may vary depending on upper air winds.

Flight Systems:


Balloon Manufacturer Kaysam
Balloon Type latex
Balloon Size 3000 gram
Payload 25.6 lbs.
Free Lift % calculated at fill
Ascent Rate 1100 fpm estimated
Descent Rate 950 fpm estimated
Parachute 10 ft
Peak Altitude determined after flight
Launch Conditions determined at launch


Payload Configuration:

Tracking and Recovery Info:


Location X Y
West Intersection of Highways 71 and 14 60 35
Touchdown (see Prediction Page)


Tactical Callsigns

Tactical Callsign Name Notes
Alpha WA0GEH and N0AUS Marty and Al Tracking and Recovery Coordinator
Bravo KB0YRZ and KC5TRB Chris and Harry  
Charlie WG0E and N0MPM Colin and Mike  
Delta W0CBH and KC0SOW Benjie and Marcia  
Echo KC0RPS Jim  
Foxtrot WB0DKT, KC0ZIE, KC6HXM, WB6KDF Glenn,  Darren, Sam and Loren  
Ground AE0SS Nick Ground Station


Internet Gateway Stations:

as seen on Findu.Com

For AE0SS-11

  • K0YG - Mark Patton, Foxfield, CO
  • K0YG-3 - Mark Patton, Foxfield, CO
  • N0PSJ - Christopher Holmes, Arvada, CO
  • WY0F - Jack Barnard, Grand Island, NE
  • KC0MWM - Roger Hammond, Grand Island, NE

EOSS wishes to express our sincere appreciation to the stations above who iGated the balloon APRS telemetry onto the internet. You have all i-gated before but did you know I publish predictions for i-gates? I keep a list of everyone who has ever i-gated an EOSS balloon flight. You're all in the list so if you're wondering when the balloon will pop up over your horizon, check out this page for future flights.  Currently predictions are being made for 28 i-gates.

We are relying heavily on real time position information available on the net to allow the FAA controllers to have up to the minute location data to assist them in air traffic control.

Redundant stations for the balloon iGating provide excellent coverage. If you are able to iGate we invite you to join the Internet Gateway Team. Contact me ( to be put in touch with the coordinator. By joining the team, you are giving peace of mind to the iGate coordinator for that flight. He knows you'll be there and he can rely on you.

Naturally, anyone can iGate data onto the net and even if you aren't a member of the team we will welcome your contribution to the internet based tracking effort. If you callsign appears on the log, you'll be shown as a contributing station as those above are.

Having more than one station covering each APRS beacon means that should a station drop out momentarily, the others can often maintain the data flow.

Thanks again guys! The FAA (and EOSS) are very grateful for your assistance in this endeavor.

Future I-Gaters:

Check out the EOSS I-Gate page for information on how to participate and why we need you.

Current I-Gate Stations:

Guys, the prediction program used to determine the track of the balloon prior to flight can now output a prediction for the Rise, Closest Approach or maximum elevation, and Set of the balloon for each of your stations. I have posted a prediction page for stations that I have been able to discover geographic coordinates. See the I-Gate prediction page for an example. The page will not be updated daily, however, it will be updated the evening prior to flight for I-gate planning purposes.

I have often been asked by iGaters when they should expect to either start receiving signals (AOS) or expect to see those signals disappear (LOS). This prediction page should answer all those questions for you.


  • Colorado University - Upward Bound - Student hands on training

note: customers are welcome to submit detailed synopses of their flights or web links to their own web sites.



Launch Site


  • by Marty Griffin, WA0GEH
  • by Colin Glennan, WG0E



Tracking and Recovery audio of the flight as recorded from the Rocky Mountain Radio League's 449.450 MHz repeater. Voice activated recording is used, so long gaps of silence are automatically removed from the recordings. Therefore, 30 minutes of audio in one of these MP3 files might represent an hour of actual elapsed time.


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Text Files

Spread Sheet Files

Mapping Files