Recap of EOSS-66

LAUNCH DATE: May 3, 2003
LAUNCH TIME: 07:10 am MST, 13:10 UTC
LAUNCH SITE: Windsor, CO (directions)

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

Launch Site - Windsor
Launch Point: 40.4737� lat.   -104.9635� long.
Ascent Rate: 1000 feet per minute
Descent Rate: 915 feet per minute
Altitude: 5020 feet
VOR Station - Akron
Latitude: 40.1555� lat.
Longitude: -103.1797� long.
Magnetic Offset: -9.2� from True Degrees
Predicted Landing Site
Landing Point: 40.6187� lat.  -103.0354� long.
Altitude: 4501 feet
Flight Time: 131 Minutes
Bearing: 83.7� True
Range: 101.7 Mi.
Actual Landing Site
Landing Point: 40.6801� lat.  -103.3158� long.
Bearing: 80.1� True
Range: 87.6 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 286.2� True
Range: 15.3 Mi.

Prediction Accuracy

How accurate are the wind predictions from NOAA. See a series of track predictions, one a day for a 7 day long period, running up to launch. This series includes the actual flight day prediction and the above recap info to compare against.

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

EOSS Frequencies:

  • Preflight Net:
    • 147.225 MHz 8 pm MDT preceding Friday night
      • 145.160 MHz simulcast in the Springs
    • 146.640 MHz will serve as a backup frequency
  • HF Net during Flight
    • 7228 KHz (see notes about this freq)
    •  starting at 13:15 UTC (6:15am MST)
  • APRS
    • 144.340 MHz
    • ID = K�YUK-11
  • Beacon
    • 147.555 MHz
  • ATV
    • 426.250 MHz (AM)
  • Tracking and Recovery Operations
    • 449.450 MHz 103.5 Hz tone RMRL Repeater
    • 146.910 MHz Sterling Repeater
    • 146.550 MHz simplex (same simplex for field and launch ops)

University of Kentucky Frequencies:

  • Telemetry
    • 145.600 MHz
    • ID = KG4YLM
  • APRS
    • 445.975 MHz
    • ID = KG4YLM-11
  • ATV
    • 923.000 MHz AM
    • 439.250 MHz AM backup if 923 MHz fails.

EOSS Grid Layout:

LocationGrid XGrid Y
Hwy 14 and 71 (west intersection)1040
Landing Point (approx.)61.953.5

The Grid Calculator uses the intersection of Hwys. 14 and 71 (west intersection) as its basis. This location is near Stoneham or 55 miles ENE of Greeley, Colorado.

  • Latitude: 40.61025� N
  • Longitude: 103.6769� W
  • GridX: 10
  • GridY: 40

Flight System:

Balloon ManufacturerKaymont
Balloon Typelatex
Balloon Size3000 gram
Payload24.77 lbs
Free Lift %22%
Ascent Rate 1101.1 fpm (calculated)
Descent Rate 900 to 950 fpm *
Peak Altitude88,661.41 ft.
Launch ConditionsGood, estimated winds 3-4 from the NW

* The descent rate is for Sea Level. It is approximate as the descent speed telemetry fluctuates quite a bit during the final phases approaching landing due to up and down drafts in a convective and windy atmosphere.

Payload Configuration:

University of Kentucky experimental inflating glider.

Schematic of Payload Train


These audio files were recorded from the 449.450 MHz RMRL repeater and contain the traffic of the Tracking and Recovery operations.

  • Preflight = From 6:45 am to 7:08 am (traffic prior to launch) 1.8 MBytes
  • Ascent = From 7:09 am to 8:25 am (liftoff to just prior to cutdown) 5 MBytes
  • Descent = From 8:25 am to 9:10 am (cutdown to touchdown and recovery) 3.3 MBytes


  • James Kilgore's Videos during the landing. 4.5 Mbytes. James was one of the members of K. Mark Caviezel's [KC�JHQ] chase team for this flight.



Unfortunately, the KØYUK-11 APRS system suffered some type of problem and data was unavailable from it.

The APRS data aboard the University of Kentucky was provided via a Kenwood D7. This payload does not include time stamped packets, so it is up to the receiving station to provide that. I had some troubles with Balloon Track decoding that type of packet and this resulted in some strange time stamps. I've cleaned up the spread sheet file below to only include data with valid time stamps. The TNC Log File includes all data.


Tracking and Recovery

by Benjie Campbell, WØCBH

Well, what a nice day to fly. I had a ball. I think Chris did too, but I don't care as I did.

Chris KBØYRZ picked me up at 4:10 am, and Russ KAØULN joined us on the road. We made it to Fort Morgan rather quickly, and had some breakfast and then took off for Sterling. We went east on highway 6, about 4 miles east, and set up on a rise. We were able to get into the Sterling repeater when we found the right frequency (145.295). Dan NØPUF, Russ, and Shawn KCØLZE all went further east to cover the east end of the flight prediction. They were not able to get into the Sterling machine, but were able to contact us on 146.550 simplex, so Chris and I acted as a relay into the Sterling repeater so Marty WAØGEH could take their bearings. It worked well. We had some glitches, but not very many.

Chris had his ATV running and he was able to see all of the flight, and had some good video of the wings deploying on the payload. I wasn't able to see it since the TV was behind my seat. Darn! I will have to watch the tape I guess.

The tracking beacon on 147.555 was very steady, thanks to Mike Manes W5VSI changing the antenna to a J-pole configuration or fixing the counterpoise. Whatever he did, it worked in the air. We did notice that we didn't hear the beacon on the ground until we were within 2 miles of it.

We were not able to track the KØYUK-11 APRS signal until one beacon hit us as we moved to the landing site. It didn't provide us with valid data either. We were not able to track the KG4YLM-11 APRS beacon either, since we didn't have a dual band radio hooked up to the TNC/computer. That will change on the next flight. You just need two dual band radios on these flights, that is all there is to it.

The recovery site was fun. All or most of the Kentucky people were there when we arrived. Travis KG4VLW showed up just as we were leaving for lunch.

The parachute was picked up by someone else besides me. I then helped Chris fold it up. Larry NαNDM and I had a private tutoring session with Mike Manes several days before the flight. This will preclude me from getting another Lawn Chair Larry award, I hope.

All in all it was a good flight and recovery, everyone had a great time. It was fun sitting in the restaurant, talking with all the U of K people. The tracking team did get T-Shirts from the U of K team, which were pretty nice. We all had a good time discussing the pros and cons of the system prep, flight and recovery. I hope they will be back and fly with us again.

webmaster note: University of Kentucky has tentatively requested a launch in January of 2004.



Nasa has posted an online story about the University of Kentucky's Big Blue project. Look for it at:

HF Radio

Bruce, NAØBR started an HF net approximately 45 minutes prior to launch on 40 meters. Unfortunately, the propagation conditions did not appear propitious and little to no traffic was passed.