Recap of EOSS-115

photo by Stephen Meer, K0SCC
Students from the University of Kentucky and Oklahoma State approach the Big Blue V glider in it's landing location on the plains of Colorado.


LAUNCH DATE: March 17, 2007
LAUNCH TIME: 8:27 am MDT (14:27 UTC)
GROUND STATION: Windsor, CO (Driving Directions)
LAUNCH SITE: Briggsdale, CO (40.63948 N, -104.2259 W)

Pre-flight Prediction and Actual Track

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

Map made with MapPoint
Prediction made with Balloon Track


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

Maps by Google Earth

Launch Site - Bryce White Site
Launch Point: 40.63948� lat.   -104.22259� long.
Grid: X=-8.29 Y=92.06
Ascent Rate: 1100 feet per minute
Descent Rate: 950 feet per minute
Altitude: 5000 feet
Predicted Landing Site
Landing Point: 39.62433� lat.  -103.19486� long.
Grid: X=46.2 Y=22.0
Altitude: 5000 feet
Flight Time: 123 Minutes
Bearing: 141.9� True
Range: 88.6 Mi.
Actual Landing Site
Landing Point: 39.75481� lat.  -103.54558� long.
Grid: X=27.5 Y=31.0
Bearing: 149.5� True
Range: 70.755 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 295.9� True
Range: 20.697 Mi.

Prediction History for EOSS-115 AVAILABLE HERE


Close up of Big Blue Touchdown and EOSS landing

Blue = Actual Track
Map made with MapPoint
Prediction made with Balloon Track

EOSS Flight Day Frequencies:

Global Frequencies

EOSS Balloon Frequencies

  • Beacon
    • 147.555 MHz
      • ID: AE0SS (CW)
  • 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
  • ATV
  • 426.250 MHz
  • AM Modulation
  • Standard ATV Module
  • Video overlay using the new Balloon LAN to bring GPS to the payload via the 2.4 GHz Zigbee BLAN
  • ID: AE0SS (audio CW)
  • Orientation: Look down 100%
  • Balloon LAN (Local Area Network)
  • Zigbee Network
  • 2.4 GHz range rf network (not 802.11)
  • System not intended to be accessible from the ground at 2.4 GHz

University of Kentucky Frequencies

  • APRS
  • 445.975 MHz
  • ID: KG4YLM-11
  • Beacon
  • 147.480 MHz 
  • ID: W5YJ
  • 50 mW output
  • ATV
  • 2.398 GHz
  • 1 watt
  • wideband FM

note: The balloon LAN freqs are posted for informational purposes only. This system is accessed via other frequencies and the 2.4 GHz traffic is very weak and intended only to reach from one end of the balloon train to the other. So, ground based receivers won't normally hear this traffic even with substantial gain antennas. A lower frequency LAN is being planned which will operate at greater RF power and offer LAN operations between the balloon and ground controllers.

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 24.1 lbs.
Free Lift % calculated at fill
Ascent Rate 1274.7 fpm average through entire ascent
Descent Rate 801.4 fpm average below 10K feet
Parachute 10 ft
Peak Altitude 89,134.84 ft. ASL
Launch Conditions Windy guesstimated at > 10 knots


Payload Configuration:

Tracking and Recovery Info:


Location X Y
Last Chance 25 30


Tactical Callsigns

Tactical Callsign Name Notes
Alpha N0MPM and N0NDM Mike and Larry Tracking and Recovery Coordinator
Bravo KB0YRZ and KC0UUO Chris and Rob  
Charlie KB0QQW Chris and Caleb  
Delta K0SCC Steve, Parker and Daryl Hartner  
Echo WA0GEH and N0AUS Marty and Al  
Foxtrot KC0VJE Louis  
Golf WB0DKT and KC0ZIE Glenn and Darren  
Hotel KC0ZLS Shaun  
Ground AE0SS Nick Ground Station

Internet Gateway Stations:

as seen on Findu.Com

For AE0SS-11

  • K0AEM-1 - Richard Beggs, Thornton, CO
  • K0YG-3 - Mark Patton, Foxfield, CO
  • KC0VJE - Louis Perley, Erie, CO
  • KC0ZLS - Shaun Bryant, Commerce City
  • KI4GYZ - Art Hostmark, Thornton, CO

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.


  • University of Kentucky will fly their Big Blue 5 experiment

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


Launch Site, Briggsdale

Landing Site (EOSS Payload Train)

Landing Site (University of Kentucky's Big Blue V glider)


Data Files

Text Files

Spread Sheet Files

Mapping Files