Recap of EOSS-84

LAUNCH DATE: September 18, 2004
LAUNCH TIME: 07:19 am MDT (13:19 UTC) approximately
LAUNCH SITE: Meadow Lake Airport, CO (directions here)

EOSS-84 Track

Blue = Actual Track
Green = Predicted Ascent Phase
Red = Predicted Descent Phase

Maps made with MapPoint
Prediction made with Balloon Track

Launch Site - Meadow Lake Air
Launch Point: 38.9527� lat.   -104.5752� long.
Ascent Rate: 1000 feet per minute
Descent Rate: 900 feet per minute
Altitude: 6874 feet
Predicted Landing Site
Landing Point: 39.315� lat.  -103.705� long.
Altitude: 4900 feet
Flight Time: 106 Minutes
Bearing: 61.5� True
Range: 52.9 Mi.
Actual Landing Site
Landing Point: 39.3368� lat.  -103.8323� long.
Bearing: 56.1� True
Range: 47.8 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 282.5� True
Range: 7.0 Mi.

EOSS Frequencies:

Global Frequencies

  • Preflight Net:
    • 147.225 MHz 8 pm MDT preceding Saturday night
      • 145.160 MHz simulcast in the Springs
    • 146.640 MHz will serve as a backup frequency
  • Tracking and Recovery Operations
    • 448.450 MHz PPFMA (100 Hz Tone) (approved-final)
    • 146.550 MHz simplex (same simplex for field and launch ops)
    • Repeater Coverage Pages - Listings of all repeaters available in the expected flight areas.
    • There may be FRS operations. Not expected this flight but see THIS PAGE for a list of channel numbers and their associated UHF Frequencies.
    • 7.228 MHz HF

EOSS Frequencies

  • Beacon
    • 147.555 MHz
      • ID: W5VSI in CW
  • APRS
    • 144.340 MHz (Payload Train)
      • ID: W5VSI-11
      • DIGI: EOSS
    • 445.975 MHz (Raven Balloon Envelope)
      • ID: K�YUK-11
    • Note: After payload separation, this APRS beacon will follow the descent of the balloon, NOT the payloads. We plan to clean up after ourselves by recovering the balloon after it lands.

FSL Frequencies

  • Packet
    • 145.600 MHz (Telemetry)
      • ID: KB�TVJ-11
  • ATV
    • 426.250 MHz (AM Color)
      • ID: KB�TVJ

Flight Systems:


Balloon Manufacturer Raven
Balloon Type plastic
Balloon Size 19,000 cu. ft.
Payload 35.9 lbs.
Free Lift % 22%
Gross Inflation 53 lbs.
Ascent Rate 907.1 fpm avg.
Descent Rate -1264.35 avg. from 10K to the ground
Parachute 10 ft. diameter
Peak Altitude 75,964.57 ft. ASL
Launch Conditions calm

Payload Configuration:

EOSS Grid:

Posted the night before the flight.

Location Grid X Grid Y
Falcon 2.7 5
Genoa 62 29
Flagler 85 30.1
Byers 23 58
Last Chance 56.4 60
Meadow Lake (launch) 4.3 5.6
Predicted Touchdown 58 32.8

Tactical Callsigns:

Tactical Callsign Name Notes
Alpha N�NDM Larry coordinator
Alpha (b) W�CBH Benjie  
Bravo K�JLZ Jim  
Bravo (b) K�AEM Richard  
Charlie KC�RPS Jim  
Charlie (b) W�NFW George  
Delta WA�GEH Marty  
Echo K�ANN Ann  
Foxtrot KI�DZ Mary Frances  
Foxtrot (b)      
Golf NQ�R Randy  
Hotel K�ANI Larry  
India N�LP Nick Ground Station

Internet Gateway Stations:

as seen on Findu.Com

For W5VSI-11

  • K�YG-7 - Mark Patton
  • WA0VSL-3 - Doug Wilson
  • WB0BLV - Leroy Sublett

For K0YUK-11

  • K0YG-7 - Mark Patton
  • WA0VSL-4 - Doug Wilson

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

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. 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.

Having more than one station covering each APRS beacon means that should a station drop out momentarily, the others maintain the data flow quite nicely.

Thanks again guys! The FAA (and EOSS) are very grateful for your assistance in this endeavor.


Launch Site:

Recovery Site:


These MP3 audio recordings were made from my home N�KKZ (10 miles east of Parker, Colorado) using a Marantz PMD-670 digital recorder connected to an Icom IC-R8500 monitor. They were edited in Adobe Audition.









The chart above illustrates why making new predictions during the flight were somewhat problematical. I probably would have gone ahead and done it if it weren't for the fact that the balloon was essentially following quite closely to the prediction regardless of the slower than expected ascent rate in the early phase of the flight.


Tracking and Recovery Perspective

by Benjie Campbell, W�CBH
assistant Tracking and Recovery Coordinator

What a great flight. As we were driving east on I-70, I mentioned to Marcia (KC�SOW) and Larry (N�NDM), that all the work getting ready for this flight was worth the view we had of the sunrise.

We met the rest of the tracking crew at the McDonald's in Limon, Colorado for a short breakfast and then left for our control position, which was located just behind the McDonald's, ha! We waited for the liftoff.

We were a little worried when parts started falling off the payload at liftoff. No one in the field had ATV equipment, since Chris (KB�YRZ) was not tracking for this flight. So, from a tracking perspective, we didn't miss the loss of that mode.

Our two tracking and coordination computers were giving us fits. We finally got one working with APRS Plus SA and were able to track the payload thru most of the flight. We never did get a visual on the balloon despite looking for it throughout the entire flight. Several other trackers with much younger eyes did. The reports from Larry (K�ANI) of the inflating and deflating of the payload balloon were great.

The community of listeners to the events on the repeater used for coordination of the trackers should remember that the personnel in the tracking vehicles have a lot to do. Unfortunately, we usually don't have time to chat with them about what we are doing. Although we appreciated individuals volunteering to assist us, we had already made arrangements for help during the evening net the day before the flight. We have done this enough to pre-arrange help with tasks that we need done. The time spent explaining this during the flight takes away from the time we need to do our jobs right in the field. It is a lot of fun to listen to the repeater during a flight, but the key word is listen. The occasional new listener who is interested in what is going on is fine, he or she becomes a potential new member, but the continued interruption of normal communications to answer the questions of someone who isn't involved in the actual process for a flight is very time consuming and a distraction to an already very busy repeater and the tracking coordinator and his team.

We need to coordinate better with Air 1. The coms between Air 1 and the Tracking Coordinator on this flight were spotty at best. We should move that com to the simplex frequency once the plane is within line of sight of the Tracking Coordinator. I will try to rectify that next time we have Air 1.

This exercise ended up being a APRS flight. We had originally planned to have Nick (N�LP) collect the bearing data and run the triangulation program from the launch site, but we didn't have time since the balloon burst before the first bearings were taken. We had three or more trackers who had a visual on the payload during the fight and decent. Marty (WA�GEH) actually saw it land. There aren't too many people that have seen that event.

So, all in all, we have a great flight and recovery crew lunch in Limon. We were able to see the launch when Cec and Larry showed us the videos they had taken of those events.


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