Flight Recap for EOSS-175

Recap Maps | Frequencies | Flight Systems | Payload Config | I-Gates | T & R | Text Recaps | Photos | Audio | Video | Data | Charts

03/27/2013 13:50 (CDT): minor edits

Flight Coordinator: Doug Gentges  and Rob Wright
LAUNCH DATE: May 2nd, 2012 (no wx delay)
LAUNCH TIMES: 10:50 am MDT (16:50 UTC) exact launch time dependent on activities at Coors Field
LAUNCH SITE: Coors Field, Denver, CO

Pre-flight Prediction and Actual Tracks

E0SS-175 AE0SS-11

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 (NO DESCENT TRACK)
Prediction and Actual tracks made with Balloon Track

Maps by Google Earth

Above Map Files available in the Data Section below

Launch Site - Coors Field
Launch Point: 39.75667� lat.   -104.99417� long.
Grid: X=.96 Y=1.06
Ascent Rate: 1500 feet per minute
Descent Rate: 1150 feet per minute
Altitude: 5277 feet
Predicted Landing Site
Landing Point: 40.27422� lat.  -103.9932� long.
Grid: X=53.7 Y=36.8
Altitude: 4500 feet
Flight Time: 103 Minutes
Bearing: 55.7� True
Range: 63.9 Mi.
Actual Landing Site
Landing Point: 40.47533� lat.  -103.68102� long.
Grid: X=69.9 Y=50.7
Bearing: 54.0� True
Range: 85.263 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 49.7� True
Range: 21.506 Mi.

Final Pre-Flight Prediction is available here
Prediction History is available here

FAA Waivers for 2012

This is an exempt flight but it never hurts to be aware of waiver information

EOSS Flight Day Frequencies:

Tracking and Recovery Frequencies

  • Preflight Net:
    • 147.225 MHz 8 pm MDT preceding night
    • 146.640 MHz will serve as a backup frequency
  • Tracking and Recovery Operations
    • Repeaters 
    • Field Simplex Frequencies  
      • 446.100 MHz simplex for field recovery operations
        • Note: Some radios insist on incorrectly placing a negative 5 MHz offset when selecting frequencies from the simplex portion of the 70 CM band. Check your radio and if this is the case. Consider programming in this simplex frequency to a memory channel as some radios have demonstrated the annoying habit of re-inserting the offset if you momentarily shift to a repeater then return to the simplex freq. Check the operation of your radio on this simplex freq to be ready for however your radio behaves.
      • 146.550 MHz Backup field simplex
    • Repeater Coverage Pages - Listings of all repeaters available in the expected flight areas.
    • There may be FRS operations see THIS PAGE for a list of channel numbers and their associated UHF Frequencies.
    • HF (possible as of this update)
      • 3.810 MHz LSB
      • 7.235 MHz LSB
  • Launch Site Simplex
    • 146.550 MHz

EOSS-175 Balloon Payload Frequencies

  • Beacons
    • 147.420 MHz
      • CW ID: K0SCC
  • APRS
    • 144.340 MHz
      • ID: AE�SS-11
      • DIGI: EOSS
      • Node: BALNOD
      • APRS Time Slotted Every 30 seconds at 0:00 and 0:30
        • power up at 58 seconds past the GPS minute to properly slot telemetry
      • Telemetry once a minute
      • Sample Data
  • 147.555 MHz
    • ID: K0SCC-11

Flight Systems:  


Balloon Manufacturer Totex
Balloon Type latex
Balloon Size 1200 g
Neck Load 8.51 lbs.
Neck Lift 11.29 lbs.
Ascent Rate 1329 fpm estimated
Descent Rate 950 fpm estimated
Parachute 5 ft.
Peak Altitude 95,000 ft. estimated
Launch Conditions determined at launch

Payload Configuration

Payload Experiment Designer

Demonstration flight for Steve Spangler Weather and Science Day 2012 at Coors Field

Experimenters are welcome to submit websites for linking or overviews which I will post on a page on the EOSS website.

Internet Gateway Stations:

as seen on Findu.Com (listed alphabetically)

EOSS-175, AE0SS-11

  • N0HIO - David Koerner, Denver, CO
  • KB0TVJ-4 - Russ Chadwick, Boulder, CO
  • KB0TVJ - Russ Chadwick, Launch Site
  • KC0D-1  - Mark Patton, Foxfield, CO
  • N0IX-12 - Doug Gentges, Tracking and Recovery Mobile iGate
  • N0EB-1 -  Richard Beggs, Thornton, CO
  • 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 30 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 (webmaster@eoss.org) 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 findu.com 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.

Tracking and Recovery  

T&R Meeting

  • Wiggins Rest Stop
  • Meet at 10:00




Grid X

Grid Y

West Intersection of CR 71 and CR 14 70 60
Test Coordinates   40.25� N  x  -104.5 � W 26.7 35.5



Tactical Call Signs 





Alpha KB0YRZ, W5EEA Chris and Mike Tracking and Recovery Coordinator
Bravo N0IX,KC0UUO, KD0QYY Doug, Rob and KJ Tracker
Charlie KC0RPS, W0NFW  Jim, George Tracker
Delta K0ANI Larry Tracker
Echo K5JFD John Tracker
Fox KB0LP Dave Tracker
Golf K0SCC Steve, Parker, Daryl Trackers
Hotel W9CN Mike Tracker
Juliet N0NDM Larry Launch Coordinator and Tracker
Kilo WB0DKT, KC0ZIE, KG6HXM, KB6OKA Glenn, Darren, Sam, Edna, Annie Trackers
Lima N0EB Richard Tracker


Text Recaps



Launch Site


Recovery Site


recorded but not posted



EOSS-175 Activities and Launch at Coors Field

by Nick Hanks, N0LP



Steve Spangler Effect Video

Spangler Effect Gang



EOSS-175, AE0SS-11


 Spread Sheets

Mapping Files


EOSS-175, AE0SS-11

by Nick Hanks, N0LP