Flight Recap for EOSS-180

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

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

Flight Coordinator: Larry Cerney

LAUNCH DATE: July 28th, 2012 (wx delay +1 day)
LAUNCH TIME: 07:10 am MDT (13:10 UTC)
LAUNCH SITE: Windsor, CO (driving directions)

Pre-flight Prediction and Actual Tracks

E0SS-180 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

Launch Site - Windsor
Launch Point: 40.47367� lat.   -104.96233� long.
Grid: X=20.00 Y=30.00
Ascent Rate: 1329 feet per minute
Descent Rate: 950 feet per minute
Altitude: 4931 feet
Predicted Landing Site
Landing Point: 40.42594� lat.  -104.81394� long.
Grid: X=27.8 Y=26.7
Altitude: 4500 feet
Flight Time: 144 Minutes
Bearing: 112.9� True
Range: 8.5 Mi.
Actual Landing Site
Landing Point: 40.52378� lat.  -104.02452� long.
Grid: X=69.2 Y=33.5
Bearing: 85.7� True
Range: 49.359 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 80.5� True
Range: 42.008 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 
    • 449.450 MHz (103.5 Hz Tone) RMRL
  • Field Simplex Frequencies  
    • 446.100 MHz simplex for field recovery operations
    • 446.150 MHz simplex for field recovery operations (Backup)
    • 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.


  • Launch Site Simplex
    • 146.550 MHz


EOSS-180 Balloon Payload 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
      • power up at 58 seconds past the GPS minute to properly slot telemetry
      • Telemetry once a minute
      • Sample Data
  • no backup

EOSS-180 Student Payload Frequencies

  • 437.405 SSB CalPoly AFSK payload


Flight Systems: 


Balloon Manufacturer Totex
Balloon Type latex
Balloon Size 3000 g
Neck Load 13.1 Lbs.
Neck Lift 15.9 Lbs.
Ascent Rate 1329 fpm estimated
Estimated Burst Alt 108,000 ft. ASL
Descent Rate 950 fpm estimated
Parachute 10 ft.


Payload Configuration: 

Payload Experiment Designer

SGC - Demosats

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-179, AE0SS-11

  • AE0SS - Nick Hanks at the Ground Station
  • KB0TVJ  - Russ Chadwick, Launch Site
  • KB0TVJ-4 - Russ Chadwick, Boulder, CO
  • KC0D-1  - Mark Patton, Foxfield, CO
  • N0EB-1 - Richard Beggs, Thornton, CO
  • N0IX-12 - Doug Gentges, Mobile iGate
  • 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  

Breakfast for the trackers will be at the Windsor Launch site.   We will leave the launch site and go directly east to near Greeley.

Johnson's corner KB0YRZ and W9CN at 5am


Location Grid X Grid Y
Windsor Launch Point 20 30
Grid Test   40.75� N , 104.333� W 52.8 49.1


Tactical Call Signs

Tactical Callsign Name Notes
Alpha WA0GEH, KC0D Marty and Mark Tracking and Recovery
Bravo N0IX , Doug President, Tracker
Charlie W9CN Mike and Miles Trackers
Delta WB0DKT, KB6OKA Glenn and Edna Trackers
Echo N0NDM Larry Launch and Grab
Foxtrot KB0LP Dave Tracker
Golf KC0RPS, N0NFW Jim, George Tracker
Hotel KB0YRZ Chris Tracker
Papa AC0RY Brian Colorado Space Grant

Text Recaps


Launch Site

  • by Mike Pappas, W9CN

Recovery Operations



recorded, not edited



EOSS-180 Launch

by Nick Hanks, N0LP








EOSS-180 AE0SS-11

The AE0SS-11 APRS system suffered a catastrophic accident that ripped the top off the unit disabling it. Pictures are available. This happened immediately after the first packet transmitted post burst. So we did compile a complete record of the ascent phase of the flight. The location of the touchdown was captured on scene by trackers with their GPSs, NOT by AE0SS-11.

The LOG from the AE0SS-11 system continued to record for several additional packets after transmitter failure. The log is annotated below by Mike Manes and has been used to create the map files


 Spread Sheets

Mapping Files