Recap of EOSS-55

KC�JHQ Home made balloon filled and ready for flight (photo by Slate, N�TQN)

LAUNCH DATE: March 23, 2002
LAUNCH TIME: 09:01:17 MST, 16:01:17 UTC
LAUNCH SITE:  Windsor, Colorado (directions here)



Balloon Track Predict vs. Actual data

Balloon Track for Windows                                Version 1.7.5
Flight Recap
Saturday, March 23, 2002           EOSS-55          DNR_02_03_23_1200Z.dat
1:54:44 PM                         Windsor                    wbaltrak.ini
Winds DataFile
Station: DNR
Date: 1200Z 23 03 02
DataFile Status: Intact
Intact Records: 75
Corrupt Records: 0
Launch Site - Windsor
Launch Point: 40.4744� lat.   -104.9628� long.
Ascent Rate: 1200 feet per minute
Descent Rate: 1230 feet per minute
Altitude: 5020 feet
VOR Station - Gill(GLL)
Latitude: 40.51� lat.
Longitude: -104.55� long.
Magnetic Offset: -10.8� from True Degrees
Predicted Landing Site
Landing Point: 40.5115� lat.  -103.664� long.
Altitude: 4500 feet
Flight Time: 88 Minutes
Bearing: 87.4� True
Range: 68.2 Mi.
Actual Landing Site
Landing Point: 41.0617� lat.  -102.8333� long.
Bearing: 69.3� True
Range: 118.5 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 48.5� True
Range: 57.7 Mi.

Post Burst Predictions

Balloon Track for Windows                                Version 1.7.5
Flight Recap
Saturday, March 23, 2002           EOSS-55            EOSS-55_02_03_23.dat
2:20:19 PM                        55 burst                   postburst.ini
Winds DataFile
Station: NN0RPM-11
Date: 1021L 23 Mar 02
DataFile Status: From GPS Data File
Intact Records: 113
Corrupt Records: 0
Launch Site - 55 burst
Launch Point: 40.9372� lat.   -103.1181� long.
Ascent Rate: 866 feet per minute
Descent Rate: 1230 feet per minute
Altitude: 5000 feet
Predicted Landing Site
Landing Point: 41.0395� lat.  -102.9168� long.
Altitude: 4500 feet
Flight Time: 19 Minutes
Bearing: 56.0� True
Range: 12.6 Mi.
Actual Landing Site
Landing Point: 41.0617� lat.  -102.8333� long.
Bearing: 59.8� True
Range: 17.2 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 70.5� True
Range: 4.6 Mi.


  • Preflight Net:
    • 147.225 MHz 8 pm MDT Friday March 22, 2002
    • 146.640 MHz will serve as a backup frequency
  • Beacon
    • 147.555 MHz CW ID
  • Tracking and Recovery Operations
    • 449.450 MHz 103.5 Hz tone required (RMRL repeater)
    • 146.550 MHz simplex (same simplex for field and launch ops)
  • Simplex at Launch Site
    • 146.550 MHz (same simplex for field and launch ops)
  • APRS - Since it is a DF hunt flight, the aprs data will not be made public until after the flight has completed.


Fox Hunt Contest

Win Prizes. See the Contest Announcement Page for details on how to qualify and participate, and of course the rules

New "Home Made" Balloon Test

HERE is Mark's outline of the balloon system

Mark KC0JHQ will be flying his homemade balloon. It is a zero pressure envelop that should ascend to around 60,000 feet plus a little where it will float. After a test of the floating capabilities, the payloads will be cutdown from the balloon via ground station commands. Limitations on this flight in order of priority

  1. Cutdown at 50 mile range from the launch site
  2. Cutdown after float test is complete
  3. Cutdown at 2 hours into the flight

The last item is automated on a timer in the event we lose the ability to transmit commands to the payload. The cutdown system is redundant. There are two separate and independent mechanisms on the payload.

We had one failure on this flight. The DF beacon and manual cutdown package seemed to die during the flight. Thus, the loss of one RDF target for the fox hunters and the inability to initiate cutdown on command.

We did have a backup cut down device on a timer and it worked just fine. Because we had to rely on the second cutdown device we were forced to float until the 2 hour timer executed its function. This forced the flight to go quite a bit longer than the management circle expected. However, we did warn the fox hunters we might go as far as 100 miles and this extension only took us out to 118 miles so it wasn't all that unexpected to folks not in the management  tracking loop.

Direction Finding Competition

by Marty Griffin, WA�GEH

EOSS #55 was a great success for the competitive DF teams.  This competition was designed to test the DF skills of anyone wishing to learn to track and chase a high altitude balloon.  As it turns out, the competitive hunt turned into a cooperative hunt as the infamous Mrs. Murphy rewrote the rules again.  That's right Ann - Mrs. Murphy.

The DF target was a homemade, 50' cylindrical balloon and a payload built by EOSS member Mark Caviezel, KC0JHQ.  Mark's balloon had an APRS package that would be tracked by his crew who included Karl Gross, N7MXO and Mark's fine friend, Leslie.

The competition hunters would be tracking a 147.555 MHz beacon.  There would also another secret APRS package so the EOSS management team could report to the FAA and maintain control.

We welcomed first-timers Jim Zimmerman, K0JLZ and his navigator John Polson WB0JDQ.  Jim is an accomplished Dfer here on the Front Range and he wanted to try his Doppler arrangement. 

Also joining us for the competition were:

  • Benjie Campbell, W0CBH and his son Jeremy Campbell
  • Dan Meyer, N0PUF and his lightbar adventures
  • Chris Krengel, KB0YRZ and his sidekick Clint Wellard, AC7FY
  • Ben Baker, KB0UBZ and his sidekick, Ann Trudeau, KA0ZFI

Marty Griffin, WA0GEH, presided as mother-hen and kept the teams in communications with each other during this adventure.

Mrs. Murphy struck shortly after launch when Ben got a call from work and had to abandon the effort.  Tough luck and we missed him and Ann on the mission.

Mrs. Murphy struck again about 40 minutes into the flight when the main beacon on 147.555 MHz failed for some reason and we were left with tracking short bursts on the no-longer-secret APRS frequency.  Quickly this competitive hunt turned cooperative.

Decisions were made to allow the balloon to loiter to assure it would clear the Pawnee National Grasslands where there are no roads.  Attempts to command a cutdown were unsuccessful and the failsafe, 2-hour timed cutdown device, managed to cut away the balloon at 10:47.

Mark, Karl and Leslie managed to locate the balloon and recover the entire 50' envelope.  They then joined the rest of the group to locate and recover the main payload.

HF proved very worthwhile as we shifted from the 449.450 repeater to the Sterling Colorado 146.91 machine.  We used 40 meters as a secondary method to keep folks in touch.  The Sterling repeater worked great all the way into the recovery site.

The recovery teams took and recorded standard LOS bearings as the payload neared the ground.  All signals and APRS were lost at LOS.  Out best calculations determined the payload had landed about 12 miles east of Lorenzo, Nebraska.  Out teams deployed east on Road 8 and spread to the north.  Finally, one of the teams heard the beacon and we zoomed in to a farmhouse and got permission to enter from the landowner.  Using DF techniques and binoculars, Dan, N0PUF spotted the orange chute.   The payload was about a mile south of the main road (Road 12). 

Mark and Leslie braved the long walk towards the payload and the rest of us toughed it by driving 2 miles over a "trail" to the payload.  Pictures were taken and a very satisfied crew knew that their teamwork had found yet another payload in a very difficult situation.

The payload was found at N41 03.935, W102 49.975.  This was about 15 miles east and one mile north of Lorenzo, Nebraska.

The drawings for the prizes were held.

  • The grand prize, a Garmen eTrex,  was won by our newcomer, John Polson, WB0JDQ who will hopefully put it to use during the next missions he works with EOSS.
  • The two Delorme Street Atlas 9.0 packages were won by:  Chris Krengel, KB0YRZ and Jeremy Campbell.
  • The two Mid-East maps were won by:  Benjie Campbell, W0CBH and Dan, N0PUF

After recovery we chowed down at the Country Kitchen where a sassy waitress generally kept the group in line and getting too heady with their success.  We then headed home back through Sterling and down I-76.

I would like to thank everyone for keeping cool heads during Mrs. Murphy's events and assuming a cooperative posture.  I would also like to thank Rick, N0KKZ for his predictions and fine data management skills as well as Nick, N0LP for keeping us updated on payload events.  This is what we do!  A good time was had by all.



Raw TNC Log File