Recap of EOSS-76

LAUNCH DATE: May 1, 2004
LAUNCH TIME: 11:31 am (17:31 UTC)
LAUNCH SITE: Deer Trail, Co (Directions)

Webmaster notes:

I've stolen shamelessly (with permission) from the University of Kentucky's website for some photos and movies linked below.

Thanks to Ralph Wallio, W0RPK, for noting that I had used the wrong ascent rate data to produce this map and the accompanying recap data. Below is the real deal.

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

Maps made with MapPoint
Prediction made with Balloon Track

Launch Site - Deer Trail
Launch Point: 39.6114� lat.   -104.0426� long.
Grid: X=11.48 Y=80.43
Ascent Rate: 1000 feet per minute
Descent Rate: 910 feet per minute
Altitude: 5205 feet
Predicted Landing Site
Landing Point: 38.6874� lat.  -103.5552� long.
Grid: X=37.9 Y=16.6
Altitude: 4500 feet
Flight Time: 132 Minutes
Bearing: 157.6� True
Range: 68.9 Mi.
Actual Landing Site
Landing Point: 38.9688� lat.  -103.58� long.
Grid: X=36.4 Y=36.1
Bearing: 150.7� True
Range: 50.8 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 356.1� True
Range: 19.5 Mi.

EOSS Frequencies:

  • Tracking and Recovery Operations
    • 448.450 MHz PPFMA Repeater (100 Hz tone)
    • 146.550 MHz simplex (same simplex for field and launch ops)
    • There may be FRS operations see THIS PAGE for a list of channel numbers and their associated UHF Frequencies.
    • 7.228 MHz HF
  • Beacon
    • 147.555 MHz
    • ID: W5VSI in CW
  • APRS
    • 144.340 MHz (primary APRS)
    • ID: K�YUK-11
  • ATV
    • 426.250 MHz
    • ID: W5VSI

University of Kentucky Frequencies

  • APRS
    • 441.000 MHz
    • ID: KG4YLM-11
  • Telemetry
    • 445.975 MHz
    • ID: KG4YLM-12
  • Beacon
    • 146.505 MHz
    • CW ID: KG4YLM
  • ATV
    • 922 MHz AM

Flight Systems:

Balloon Manufacturer Kaymont
Balloon Type latex
Balloon Size 3000 gram
Payload 23.15 Lbs.
Free Lift % no info yet
Ascent Rate 1241.29 fpm calc from telemetry
Descent Rate not enough data
Parachute 10 ft. diameter
Peak Altitude guesstimated at 65,000
Launch Conditions calm

Payload Configuration:

Contained in the PDF below, the layout of the payload train.

EOSS Grid:

Location Grid X Grid Y
Punkin Center 30 28
Yoder 2 27.5
Karval 39 20
Junct. Hwy 86 and I-70
Exit 352 I-70
23 60
Matheson 15.5 50.5
Launch Site 11 80.7
Predicted Landing (fri night) 37.2 24.1

Tactical Callsigns:

Tactical callsign(s) name(s)
alpha WA0GEH Marty (T&R coordinator)
bravo W0CBH Benjie
charlie KB0YRZ & KB0UBZ Chris and Ben
delta N0PUF Dan
echo N0NDM & N5LPZ Larry and Mike
foxtrot K0JLZ & K0AEM Jim and Richard
golf KA0ULN Russ
hotel KI0DZ Mary Frances
india N0LP Nick (Ground Station)
kilo KG4YLM Bill (U of KY)

Internet Gateway Stations:

as seen on Findu.Com

For K0YUK-11

  • KH2NC - Rick Nilson
  • K0YG-7 - Mark Patton
  • K0ANI-9 - Larry Cerney
  • K0QED - Lee Inman

For KG4YLM-11

  • K0YG-7 - Mark Patton
  • K0QED - Lee Inman
  • KI0KN - James Cizek

EOSS wishes to express our sincere appreciation to those 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.

The redundant stations for the balloon provide excellent coverage. If you go to and enter in the callsigns of any of EOSS's APRS payload systems to retrieve the raw position data you will note that many of these stations contribute to the flow of information. In the event of a station dropping out momentarily, the others pick up the slack quite nicely.

Thanks again guys! The FAA (and EOSS) are very grateful for your assistance in this endeavor.

Just to give credit where credit is due:

Open these files and see how each i-gate station contributed to the FAA reporting for EOSS-76. The i-Gate is the last call sign before the actual packet APRS data.


From the Launch Site

From the Recovery Site

  • Photos by Larry Noble, N�NDM
  • Photos (3 pages) by Chris Krengel, KB�YRZ

University of Kentucky

  • On this Page are a few captures from the onboard camera of the deployed wings and a group shot of the student team.


The 3000 gram balloon post flight. Photo courtesy U of KY
Click HERE or on image for larger version.


University of Kentucky

There are several really worthwhile videos available at the University of Kentucky's servers. Some of them are small enough to be viable over dialup, however the good ones are pretty much broadband only, meaning they are many megabytes BIG. This launch video will remain on the website "permanently" as a honor to the U of KY team that managed to squeeze so much into so little space. :-)


As always, video may be removed to conserve space. You have until at least June 15th, 2004 to download this file.


Below are links to the audio recordings of the Tracking and Recovery net on the Pikes Peak FM Association's 448.450 MHz repeater. They are all MP3 files averaging 1.5 to 5 megabytes.


We had our share of problems this time out. One APRS system failed to lock up, the other had audio problems. However, below is the data from the K0YUK-11 APRS system. This file is a compilation of data gleaned from my system, Findu and the iGaters and the EOSS ground station.


Text File

Data from the KG4YLM-11 APRS was unusable. However, the Findu log of the data is linked above in the Internet Gateway Stations section. That data is in compressed binary form however, you can see that it essentially does not change during the flight indicating a malfunctioning GPS/APRS combination.


Tracking & Recovery

by Benjie Campbell, W�CBH

This was a great flight! We got to sleep longer, drive slower, eat more, and have a great post flight lunch. Wow, can't beat that with a balloon. I vote for later launches, understanding what the complications have been in the past, but it was fun to do this once.

We had more trackers, thanks Mary Frances (KI�DZ) for bring the kids and hubby, we have missed you guys. Hope to see you next time.

The trip out on highway 86 from Parker, was a bit slick. I left a little before 6:00 am. We only drove 35 to 40 mph for half the trip. It was pretty slick on the shaded side of the road. Once we got to Kiowa, road conditions were better and we could go faster. Russ, (KA�ULN) followed us from his home in Elizabeth. He went north at I-70 to help with the launch team and we went south to meet up with the rest of the trackers at Limon.

We had seven or eight trackers at breakfast at the Denny's and 10 of the University of Kentucky students. We had time to eat, and prepare our vehicles, and computers before we all headed south.

Marty (WA�GEH), our tracking and recovery coordinator, asked Marcia and I to go to Karval and then west a bit. We set up on a dirt road, and waited for the balloon to launch. We had an hour to get things set and practiced a bearing or two, and got the programs running. I am still having troubles with grid calc, and my GPS receivers. On the way home I hooked up the Garmin and it worked great, so I will not use the new GPS receivers with the grid program. The laptop stand in the jeep worked great. No more bouncing and falling off my lap.

The balloon burst early so we all had to move north to the new landing site, and we didn't get there in time to see the landing, but Mary Frances arrived first and we were a close second.

We DF'ed the balloon to the west of a north/south dirt road, and Mary Frances' kids spotted the parachute blowing in the wind. It was just over a ridge line, not visible from the road, unless the parachute was billowing high enough. Great eyes kids have.

Soon, the University of Kentucky people arrived along with the rest of the tracking team. We had the owner of the land and several of his neighbors watching the recovery, and they all helped to bring out the payloads and students.

We are getting more of the eastern Coloradans interested in our flights. We might need to start notifying the newspapers out there of upcoming activities. We might have more observers.

Again, it was a very fun flight, and successful in the recovery. Everything worked well and I am looking forward to the next flight.



University of Kentucky's ambitious program to develop a glider for use on Mars requires more than a short paragraph here so, visit their Big Blue Site, to learn more about the program.

HF Radio

  • Some activity on 7.155 MHz, primarily the Kansas flight.