Flight Recap for EOSS-174

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: Jim Langsted - KC0RPS
LAUNCH DATE: April 14th, 2012
LAUNCH TIMES: 07:09 am MDT (13:09 UTC)
LAUNCH SITE: Windsor, CO (Click Here for directions)

Pre-flight Prediction and Actual Tracks

E0SS-174 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 - Windsor
Launch Point: 40.47367� lat.   -104.96233� long.
Grid: X=12.64 Y=.57
Ascent Rate: 1329 feet per minute
Descent Rate: 950 feet per minute
Altitude: 4931 feet
Predicted Landing Site
Landing Point: 41.51849� lat.  -104.10326� long.
Grid: X=56.9 Y=72.7
Altitude: 4500 feet
Flight Time: 128 Minutes
Bearing: 31.5� True
Range: 84.9 Mi.
Actual Landing Site
Landing Point: 41.34421� lat.  -104.1936� long.
Grid: X=52.3 Y=60.7
Bearing: 33.5� True
Range: 72.261 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 201.3� True
Range: 12.91 Mi.

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

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 
      • South End of Recovery
      • North End of Recovery (Wyoming)
        • 146.775 MHz (114.8 Hz Tone) Cneyenne (Linked to Albin)
        • 147.165 MHz (114.8 Hz Tone) Albin (Linked to Cheyenne)
    • 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-174 Balloon Payload Frequencies

  • Beacons
    • 147.555 MHz
      • CW ID: AE0SS
  • 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


Video Might Be available, check http://www.eoss.tv

Various Online Live Tracking Pages

Flight Systems:  


Balloon Manufacturer Totex
Balloon Type latex
Balloon Size 3000 g
Neck Load 22.1 lbs.
Neck Lift 26.4 lbs.
Ascent Rate 1329 fpm estimated
Descent Rate 950 fpm estimated
Parachute 10 ft.
Peak Altitude 97,000 ft. estimated
Launch Conditions determined at launch

Payload Configuration: 

Payload Experiment Designer

SGC Demosats, Metro State

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-174, AE0SS-11

  • K0ANI - Larry Cerney, Denver, CO
  • KB0TVJ - Russ Chadwick, Launch Site
  • KB0TVJ-4 - Russ Chadwick, Boulder, CO
  • KC0D-3 - Mark Patton, Foxfield, CO
  • N0EB-1 -  Richard Beggs, Thornton, CO
  • N0IX-12 - Doug Gentges, Tracking and Recovery Mobile iGate
  • N0PSJ - Christopher Holmes, Arvada, CO
  • N0SPB - Shaun Bryant, Commerce City, CO
  • N0SPB-10 - Shaun Bryant, Tracking and Recovery Mobile iGate, mostly in Albin WY for the flight.

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 




It looks like we will be heading to Wyoming for this recovery.  Bring your passports!

Please note the Cheyenne and Albin repeater frequencies in the Cheyenne area for our recovery frequencies. 

We will formally, under net control, move to repeater frequencies

Fill up with gas! Wear warm clothes and good boots.  Bring tow ropes!

Only one, well-laden balloon this flight.

Greet Lia Mathews, the new coordinator for Colorado Space Grant.

A Glider with cell-phone messaging connections will be released 50 minutes into the flight.  Trackers may
try recovery efforts after our payload is recovered.  More later.




Grid X

Grid Y

West Intersection of CR 71 and CR 14 80 10
Test Coordinates   41.25� N  x  -104.5� W 37.3 54.1



Tactical Call Signs 





Alpha WA0GEH Marty Tracking and Recovery Coordinator
Bravo K0SCC Steve, Daryl and Parker Tracker, Driving Pro, Optical Tracking Asset, Food and Beverage
Charlie KC0RPS,  N0NFW, N0SSW  Jim, George, Harlan Flight Coordinator and Tracker
Delta KB0YRZ Chris Tracker
Echo none    
Fox KC0UUO, KD0QYY,N0IX, KD0RPF Rob and KJ, Doug, Alan Presidential Timber and First Lady and two Trackers
Golf N0NDM Larry Launch Coordinator, Tracker

Text Recaps



Launch Site

Recovery Site



recorded but not posted



EOSS-174 Launch

Nick Hanks, N0LP






EOSS-174, AE0SS-11


 Spread Sheets

Mapping Files