Announcement of EOSS-115

LAUNCH DATE: March 17, 2007
LAUNCH TIME: 8:00 am MDT (14:00 UTC)  might slip or be planned to go at 08:15 MDT
GROUND STATION: Windsor, CO (Driving Directions)
LAUNCH SITE: Briggsdale, CO (40.63948 N, -104.2259 W)

Google Earth Map of the launch site we used for 114. I'm assuming we'll go there again this time out.

Pre-Flight Information

On Air Nets

Check into the weekly EOSS net every Tuesday evening, except the 2nd Tuesday of the month when we hold our face to face meetings.

  • Tuesdays at 8 PM (20:00) Local time
    • 147.225 MHz 107.2 Hz tone CRA Repeater (Denver)
    • 145.460 MHz 107.2 Hz tone CRA Repeater (Boulder) manual link required (link may be unavailable)
    • 145.160 MHz 107.2 Hz tone CRA Repeater (Colorado Springs) full time link active
    • 146.640 MHz backup DRL Repeater (Denver only)

Pre-Flight Coordination Net

The evening prior to flight we hold a coordination net at 20:00 Local Time to assign the grid information and tactical callsigns. Any last minute information, launch time changes, launch location changes, maybe even a cancellation will be announced on this net.

Tracking and Recovery Team
Flight Day Breakfast

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.

Flight Systems:

Balloon Manufacturer Kaysam
Balloon Type latex
Balloon Size 3000 gram
Payload 24.1
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


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.

Payload Configuration:

Tracking and Recovery Info:


Location X Y
Last Chance 25 30
Touchdown (see Prediction Page)


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 and Parker  
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:

Future I-Gaters:

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

Current I-Gate Station:

If you are present at your iGate during the flight try and monitor the tracking and recovery frequency. The ground station likes to check the frequency prior to launch to find out if any stations are out there ready to igate the traffic onto the net for the FAA to monitor.

The prediction program used to determine the track of the balloon prior to flight can now output a prediction for the Rise, Closest Approach, 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.

Your Log Files

Our technical committee members would also request you open a log file and record all the packets you hear and forward onto APRS-IS. Whenever there is a technical failure of a package it is always helpful to have the most complete dataset possible to attempt to determine the cause of failure and possible fixes. After a flight send your data files to me (webmaster) and I will distribute them to the appropriate payload builders. They appreciate these logs even if all goes fine during a flight.


This time out EOSS will have three customers.

  • 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.