Recap of EOSS-87

LAUNCH DATE: 26-Feb-2005
LAUNCH TIME: 08:56 am MST (15:56 UTC)
LAUNCH SITE: Windsor, CO (directions)

EOSS-087 Track

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

Maps made with MapPoint
Prediction made with Balloon Track

Launch Site - Windsor
Launch Point: 40.4737� lat.   -104.9623� long.
Grid: X=-2.39 Y=35.57
Ascent Rate: 1100 feet per minute
Descent Rate: 910 feet per minute
Altitude: 4931 feet
Predicted Landing Site
Landing Point: 40.1082� lat.  -104.4331� long.
Grid: X=25.5 Y=10.3
Altitude: 4900 feet
Flight Time: 125 Minutes
Bearing: 132.0� True
Range: 37.6 Mi.
Actual Landing Site
Landing Point: 40.0557� lat.  -104.6028� long.
Grid: X=16.6 Y=6.7
Bearing: 146.6� True
Range: 34.5 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 248.0� True
Range: 9.7 Mi.

EOSS Frequencies:

Global Frequencies

  • Preflight Net:
    • 147.225 MHz 107.2 Hz tone
  • Tracking and Recovery Operations
    • 449.450 MHz RMRL Repeater(103.5 Hz Tone)
    • 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 (sporadic usage)
  • HF Net
    • 7.228 MHz
      • The HF net may or may not be in operation for any particular flight. It depends on whether or not we get a volunteer net control station.
      • This net will move UP (away from Advanced and Extra band slices) to accommodate QRM. It should not set up above 7.250 MHz so if you don't hear it in that slice of spectrum, it is probably inactive. However station to station traffic for the Tracking and Recovery guys might pop up.

Balloon Frequencies

  • Beacon
    • 145.600 MHz
    • 446.025 MHz
      • ID: K�ANI-11
      • Tone then CW ID and APRS packet
      • Flight Test of system
  • APRS
    • 144.340 MHz
    • 144.390 MHz (wasn't heard during flight)
      • ID: NG�X-11
      • Flight Test of Mark Caviezel's new APRS package
      446.025 MHz (wasn't heard during flight)
    • 445.950 MHz
      • ID: K�YUK-11
    • 147.555 MHz
      • ID: W0WYX
      • Packet burst on the output of the RMRL Crossband repeater
  • Cross Band Repeater
    • Input: 445.975 MHz
    • Output: 147.555 MHz

Flight Systems:

Balloon Manufacturer Kaymont
Balloon Type latex
Balloon Size 1200 gram
Payload 13.1 lbs.
Free Lift % 20%
16.1 lbs.
Ascent Rate 880 fpm calculated
Descent Rate 1148.622 fpm avg (7500 - 5000 ASL)
Parachute 5 ft.
Peak Altitude 83,916.99 ft. ASL
Launch Conditions light winds

Payload Configuration:


NOAA AirCore� Atmospheric Profiler

Nick Hanks, N�LP is holding the atmospheric sampler. Behind him, Russ Chadwick KB�TVJ is explaining how it works. This version of the sampler is 14 or 15 meters long.

This coil of tubing will be sealed at one end, open at the other. As the balloon ascends to burst altitude, the air within the tube will evacuate. Then during descent it will refill with air.

Because of the inner diameter of the tube (small) and the way it will be pressurized from the atmosphere as it descends, the guys up at Boulder NOAA believe this will give them a good peek at atmospheric constituents at various altitudes. For a system to be workable, the length of the tube will need to be extended to between 40 and 80 meters in order to obtain sufficient resolution to be useful.

AirCore� Report

by Russ Chadwick, KB�TVJ

The AirCore� experiment atmospheric sampling tube was carried on EOSS87 inside the parachute spreader ring and this arrangement worked well. 

Everything worked as planned during the launch, flight and recovery. The EOSS Tracking and Recovery Team had the tube capped within 30 seconds after the balloon landed, a remarkable achievement.  It�s hard to imagine that things could have been done any better than that.

The difficulties started when the CO2 content of the tube was to be analyzed at Atmospheric Observing Systems, Inc. (AOS) in Boulder.  Russ Chadwick and Aaron Watson of NOAA carried the tube from the recovery site to Boulder where Jim Smith, the owner of AOS, was at the AOS facility and ready to do the measurement. 

T here appeared to be problems getting the measurement system calibrated.  After about 5 hours of effort, it was determined that the system was calibrated, but that the aluminum used in the tube was absorbing CO2 .  This was unexpected because calibrated air with 378 parts per million concentration of CO2 is routinely stored in aluminum tanks at high pressure for years without any change in the CO2 concentration.  After this finding was verified with four different tests, it was decided to do an uncalibrated measurement of the CO2 in the AirCore� tube.  This took about 10 minutes and showed that there were more variations in CO2 concentration at the lower altitudes than at the higher altitudes.

Over the next few months, NOAA will do work to determine a more suitable material for the AirCore� sampling tube.  Hopefully, in the late spring or early summer, this experiment will be redone.  It is hoped that this could become a fairly routine measurement that could be done by amateur ballooning groups around the country.

webmaster link: leads to the Atmospheric Observing Systems webpage dealing with the CO2 analyzer.

Internet Gateway Stations:

as seen on Findu.Com


  • K�YG-7 - Mark Patton

For W0WYX-11 (RF Gated to 144.390 then i-Gated to the net)

  • N�TI - Bob Schellhorn, RF Gate
  • K�ANI - Larry Cerney, I-Gate

For AE�SS-11

  • K�UT - Bill Beach
  • K�YG-7 - Mark Patton

for K�YUK-11

  • K�UT-3 - Bill Beach
  • K�YG-7 - Mark Patton

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. 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 maintain the data flow quite nicely.

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, 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 Info:

EOSS Grid:

Location Grid X Grid Y
Intersection 71 and 14 (west) 65 45
Hudson 14 8
Nine Mile Corner 70 12.5
Rockport 6 65

Tactical Callsigns:

Tactical Callsign Name Notes
Alpha WA0GEH Marty coordinator
Bravo KB0YRZ Chris  
Charlie W0CBH and N5LPZ Benjie and Mike  
Delta KC0RPS  and W0NFW Jim and George  
Echo NG0X and KC0TLK Mark and Yolanda  
Foxtrot K0LOB and KC0QHI Jim and Jackie  
Golf KB0TVJ Russ  
Hotel K0SCC Steve and Whitney  
India N0LP Nick Ground Station


Our Customer

Edge of Space Sciences

For the past several years EOSS has been flying "fun flights". Those are flights for the express purpose of testing new payload systems, running the tracking and recovery team ragged and generally having a good time with no customer requirements to be met. Each flight has a specific goal besides the having fun aspect. When that goal is developed, I'll post it here.

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 Windsor, Colorado. Flight day coverage may vary depending on upper air winds.


Launch Site (Windsor)

Recovery Site

Audio Files

Audio files are often removed to conserve server disk space. If these files are removed, they will still be available on request.

Rocky Mountain Radio League 449.450 MHz repeater tracking and recovery net

Rocky Mountain Radio League Cross Band repeater

  • eoss087_xband.MP3 1.3 MB, this is a short file with approximately 12 minutes of audio. I wasn't monitoring the radio that received and recorded this so, I'm not sure what happened with the rest of the audio.

Data Files logs

Spread sheet data


HF Radio

Usually starts 30 minutes, frequency posted above