note: The Pioneer Astronautics recap and various telemetry files are linked below.

LAUNCH DATE: August 26, 2000 
LAUNCH TIME: 15:21 UTC - 09:21 MDT
LAUNCH SITE: Moved to the Byers 


Balloon Track for Windows                                Version 1.6.3
Flight Recap
Saturday, August 26, 2000          EOSS-43          DEN_00_08_26_1200Z.dat
11:55:29 AM                         Byers                     wbaltrak.ini
Winds DataFile
Station: DEN
Date: 1200Z 26 AUG 00
DataFile Status: Errors in Source File
Intact Records: 34
Corrupt Records: 1
Launch Site - Byers
Launch Point: 39.7032� lat.   -104.2622� long.
Ascent Rate: 1221 feet per minute
Descent Rate: 1230 feet per minute
Altitude: 5400 feet
VOR Station - Falcon(FQF)
Latitude: 39.6867� lat.
Longitude: -104.6233� long.
Magnetic Offset: -10.0� from True Degrees
Maximums Enroute
Distance to LOS: 423.5 Mi.
Maximum Range: 8. Mi.
Maximum Winds: 29.9 mph from 90� at 102,887 feet altitude
Burst Data
Burst Point: 39.7672� lat.  -104.3124� long.
Burst Time: 81.2 minutes
Burst Altitude: 104,504 feet
Burst Bearing: 328.9�
Burst Range: 5.2 Mi.
Predicted Landing Site
Landing Point: 39.8043� lat.  -104.2723� long.
Altitude: 5400 feet
Flight Time: 112 Minutes
Bearing: 355.6� True
Range: 7.0 Mi.
Actual Landing Site
Landing Point: 39.911� lat.  -104.358� long.
Bearing: 340.5� True
Range: 15.2 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 328.4� True
Range: 8.7 Mi.


Red Track = Prediction
Black Track= True Track (as received)
Touchdown reported by K0ANI as packet received from the payload on the ground



  • The �Mars Micro Balloon Probe� which will place a series of balloons in the Martian atmosphere. The objective of this flight are to test and develop inflatable gases from compounds that are normally liquids at Standard Temperature and Pressure (STP). The Mars surface pressure is simulated at 100,000 feet above sea level, thus the experiment on an EOSS balloon. This experiment will attempt to inflate balloons using various compounds. This will also permit a test of the deployment canisters required on Mars.

    The EOSS Shuttle II ATV camera will monitor the balloon deployment and inflation. Tune in for the excitement.


  • Pioneer Astronautics, Dr. Robert Zubrin, Dean Spieth, �Mars Micro Balloon Probe�.


  • Preflight Foxhunt Net 8 pm the night before flight
    • 147.225 MHz Colorado Repeater Association
  • Launch Site:
    • Simplex 146.550 MHz
  • Telemetry:
    • 144.340 MHz APRS, Temps in and out, housekeeping, GPS navigation
  • ATV
    • 426.250 MHz NTSC video
  • Beacon
    • 147.555 MHz
  • Crossband Repeater 
    • Did not fly
  • APRS
    • APRS String on the output of the EOSS Shuttle II
  • Foxhunters:
    • 449.450 MHz Rocky Mountain Radio League (RMRL)
    • 146.58 MHz Simplex Field Frequency
  • HF Net 7.235 MHz

Recap of the Pioneer Astronautics Experiment

Here is a PDF file that contains a full recap of the Pioneer Experiment, with LOTS of graphs, pictures and information regarding their tests.

eoss43summary.pdf ~ 135Kb

If you do not have the Acrobat reader for PDF files, then check the EOSS Viewer Download page.


The primary objective of the flight was a success. At approximately 97,000 feet the �Mars Micro Balloon Probe� was successfully deployed and inflated.

GPS was intermittent, usually locked in only 2D mode thus not giving altitude information.

Additional information is welcome.


Several people have forwarded on Logs of the flight. I've posted two zip files

K0UT's Log Files Include:

  • A plain text TNC log file
  • A plain text log file of Pioneer's GPS transmissions
  • An APRS-PLUS Log file of the flight
  • An APRS-PLUS Log of K0ANI's search for the payload

My Telemetry file contains:

  • A plain text TNC log file
  • An APRS-PLUS Log file of the flight
  • A GIF of the flight (seen above)
  • A Street Atlas Plot of the above screenshot (you can zoom in and see details in SA)
  • The flight recap (as above)
  • A simulated APRS file of the prediction (it's used in the above screen shot to show the predicted path)