Recap of EOSS-64

LAUNCH DATE: March 30, 2003
LAUNCH TIME: 07:16 am MST, 13:16 UTC
LAUNCH SITE: Meadow Lake Airport (directions)

Payload - W5VSI-11 (to the ground)

Green = actual track
Purple = predicted ascent
Red = predicted descent


Balloon - K�YUK-11 (data ends at 8,765)

Green = actual track
Purple = predicted ascent
Red = predicted descent

Launch Site - Meadow Lake Air
Launch Point: 38.9527� lat.   -104.5752� long.
Grid: X=12.3 Y=117.0
Ascent Rate: 1000 feet per minute
Descent Rate: 1384 feet per minute
Altitude: 6874 feet
Predicted Landing Site
Landing Point: 37.8499� lat.  -103.9884� long.
Grid: X=44.5 Y=40.8
Altitude: 5000 feet
Flight Time: 98 Minutes
Bearing: 157.2� True
Range: 82.5 Mi.
Actual Landing Site
Landing Point: 37.808� lat.  -104.0297� long.
Grid: X=42.3 Y=38.0
Bearing: 159.3� True
Range: 84.4 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 218.0� True
Range: 3.7 Mi.

If an EOSS payload is highlighted, there is a link to an information page about that payload.


  • APRS in payload train
    • 144.340 MHz
    • ID
      • Callsign W5VSI-11
      • Digi EOSS
      • Node BALNOD
  • APRS on balloon
    • 445.975 MHz
    • ID: K0YUK-11
  • Beacon
    • 147.555 MHz
  • ATV
    • 426.250 MHz (AM)
  • Tracking and Recovery Operations
    • 448.450 MHz 100 Hz tone PPFMA Repeater
    • 145.355 MHz 100 Hz tone PPFMA Repeater (south of Pueblo - linked to 448.450 MHz)
    • 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)

Flight System:

Balloon Manufacturer Raven
Balloon Type Plastic
Balloon Size 19,000 Cu Ft
Nozzle Lift 50 lbs.
Free Lift % 25%
Gross Inflation 53 lbs.
Ascent Rate 997.7 fpm post flight average
Descent Rate 1153.5 fpm average from 10k ft. down
Peak Altitude  74167.32 ft ASL
Launch Conditions light winds

Gross Inflation = balloon weight + parachute weight + payload weight + free lift.

See NOTES below regarding payload train configuration

Payload Configuration:


GAINS Pump Test payload

Related Web Pages

Tracking & Recovery Grid

Location X coord Y coord
Pueblo 10 70
Hawley 59 50
Agular 9 10
La Junta 69 50
Launch Point 13 117
Predicted Touchdown 41 32

Hawley is the center site for use by Grid Calculator

These coordinates are for the intersection of roads 10 (east/west) and 71 (north/south). 71 intersects 10 in two locations approximately 1/2 mile apart. These coordinates are taken from the Eastern intersection, closest to the town of Hawley.

  • latitude = 37� 58.947' N
  • longitude = 103� 43.225' W
  • X = 59
  • Y = 50

Tracking Stations as of Saturday Night

  • Alpha = WA0GEH
  • Bravo = KB0YRZ
  • Charlie = N0NDM & W0CBH
  • Delta = N0PUF
  • Echo = KC0CNT
  • Foxtrot = KC0JHQ (ground station bearings)
  • Golf = K0JLZ
  • Hotel = N0LP (computer tracking from ground station)
  • Excel Spread Sheet Triangulation = WB3JZV

Special Thanks:

We would like to express our appreciation to

  • John, N�KIC
  • Lee, K0QED

Their iGating of the packet data to the internet was of inestimable value. The FAA folks were very impressed. One controller was heard to remark that the system was "awesome". Nothing like bringing the FAA directly into the loop via the net, and the efforts of our local volunteers.

Thanks also go to Russ, KB�TVJ for designing the web interface to and Steve Dimse the author and maintainer of Findu!

Tracking and Recovery Triangulation Analysis

Data Files:

Plain Text

Spreadsheet (comma delimited)


Usually the charts are pretty much identical flight to flight with minor variations. However, this time we had a telemetry stream from both the balloon envelop and the payloads. This offers interesting charts comparing the descent rates.


Recap Stories:

From Benjii, W0CBH

Hi gang.

Well, I for one am a little tired.

2:00 am came pretty early. Larry Noble, N0NDM was on time at 3:00, oh heck he was a minute late. We went straight south to Walsenburg, and then east on Highway 10.

We had about 1/2 an hour to get stuff hooked up (it wasn't enough time) and start taking bearings. We still had too much junk and not enough time. We couldn't get the grid tracker program to track the balloon, but it still worked great as a grid tracker. We used the jeep mounted antenna for 2 meter bearings, and Larry's hand held antenna with the new attenuator. We would then average the bearings. The beacons were great and didn't seem to wander so much.

When the cutaway occurred we ended up finding the balloon beacon first and tracked it to a visual sighting which was across a big field to the east of the road. We couldn't find an easy way to it. After visiting two farm houses we decided to head east to road 5 and then south. By then Larry K0ANI had located it, and was picking it up.

We then continued south on 5 and ended up with Jim K0JLZ and got an eyeball on the payload. Then the beacon started coming in. We drove in with the land owner, and found it about 2 miles from the fence. We had lunch with the gang in Fowler, and got home about 3:30 pm.

Great time, good weather, and great scenery. We have some more ideas about what not to take next time, we will see if we stick to the plan.


General Radio Footprint for the flight