Recap of EOSS-127

by Colin Glennan, WG0E

Chris KB0YRZ leading the students to the LZ

LAUNCH DATE: April 20th, 2008
LAUNCH TIME: 07:27:14 MDT (13:27:14 UTC)
LAUNCH SITE: Windsor, CO (directions)

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

Map files available in the data section

Launch Site - Windsor
Launch Point: 40.47367� lat.   -104.96233� long.
Grid: X=-37.46 Y=-13.43
Ascent Rate: 1400 feet per minute
Descent Rate: 950 feet per minute
Altitude: 4931 feet
Predicted Landing Site
Landing Point: 41.40265� lat.  -103.588� long.
Grid: X=34.2 Y=50.7
Altitude: 4500 feet
Flight Time: 130 Minutes
Bearing: 47.7� True
Range: 96.2 Mi.
Actual Landing Site
Landing Point: 41.12191� lat.  -104.03606� long.
Grid: X=11.1 Y=31.3
Bearing: 46.9� True
Range: 65.932 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 230.3� True
Range: 30.272 Mi.

Prediction History is available here

EOSS Flight Day Frequencies:

Global Frequencies

  • Tracking and Recovery Operations
    • VHF/UHF
      • North flight track: 449.450 MHz RMRL Repeater (103.5 Hz Tone)
      • 147.165 MHz 114.8 Hz tone Albin repeater for Nebraska
      • 147.105 MHz 114.8 Hz tone Cheyenne
      • 146.550 MHz simplex (for both field ops and the launch site)
      • Repeater Coverage Pages - Listings of all repeaters available in the expected flight areas.
    • HF
      • 80 meters 3.815 MHz
      • 40 meters 7.283 MHz

EOSS-127 Balloon Frequencies

  • Beacons
    • 147.555 MHz
      • CW ID: AE0SS
  • 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 unknown
Free Lift % calculated at fill
Ascent Rate 1400 fpm estimated
Descent Rate 950 fpm estimated
Parachute 10 ft
Peak Altitude 103,982 ft. asl
Launch Conditions determined at launch


Payload Configuration:

Tracking and Recovery Info:


Location X Y
Rt 71 & 14 (West Intersection) 30 -4
Touchdown (see Prediction Page)


Tactical Callsigns

Tactical Callsign Name Notes



Colin & Rob

Tracking and Recovery Coordinator











Glenn, Sam, and Jon Pilsner

Jon is with the Loveland Reporter-Herald















Larry & Benjie

Launch Coordinator



Steve & Daryl









Ground Station

Internet Gateway Stations:

as seen on Findu.Com

For AE0SS-11

  • K0ANI-14 - Larry Cerney, mobile with data connection
  • K0UT-1 - Bill Beach, Ft. Collins, CO
  • KB0TVJ-4  - Russ Chadwick, Boulder, CO
  • KC0D-3 - Mark Patton, Foxfield, CO (new callsign)
  • KG0W - Matt Kassawara - Cheyenne, WY
  • N0LP - Nick Hanks, ground station?
  • N0PSJ - Christopher Holmes, Arvada, CO

EOSS wishes to express our sincere appreciation to the stations above who iGated the balloon APRS telemetry onto the internet. 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 29 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.

Experimental Systems

Colorado University flew several demo balloon sats

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


Launch Site

Recovery Area

  • by Jim Langsted, KC0RPS
    • page 1 - Students and Payloads
    • page 2 - Drive in and EOSS folks
  • by Mike Pappas, W9CN
  • by Colin Glennan, WG0E


Note: more than 90% of the T&R traffic occurred on repeaters out of the range of the monitoring station. Thus most of the traffic heard here is relayed into the main net. It may still prove interesting and useful.


Tracking and Recovery Audio


Launch sequence photographed by Nick Hanks, N0LP



Spread Sheets

Mapping Files