Recap of EOSS-67

Recap of EOSS-67

Mike Gray [KD7LMO] photo of the lift off of GPSL 2003 balloons.
Click picture for slightly higher resolution image.

Links to other GPSL recaps are available at the Great Plains Super Launch 2003 Web Page

LAUNCH DATE: June 14, 2003
LAUNCH TIME: 07:35 am MST, 13:35 UTC
LAUNCH SITE: Deer Trail (directions)

Launch Site - Deer Trail
Launch Point: 39.6114� lat.   -104.0426� long.
Grid: X=15.69 Y=29.57
Ascent Rate: 1000 feet per minute
Descent Rate: 915 feet per minute
Altitude: 5205 feet
Predicted Landing Site
Landing Point: 39.6754� lat.  -103.7823� long.
Grid: X=29.5 Y=34.0
Altitude: 4501 feet
Flight Time: 131 Minutes
Bearing: 72.2� True
Range: 14.5 Mi.
Actual Landing Site
Landing Point: 39.4926� lat.  -103.7141� long.
Grid: X=33.2 Y=21.4
Bearing: 115.0� True
Range: 19.3 Mi.
Difference from Predicted to Actual Landing Site
Bearing: 163.9� True
Range: 13.1 Mi.

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

EOSS Frequencies:

Full Frequency Guide for GPSL Balloons

(note: the number in parenthesis following the frequency is the time slot in seconds after the GPS minute)

EOSS Grid Layout:

Location X Coord Y Coord
Last Chance 39.5 38.5
Deer Trail 15 30
Arriba 56 8
Akron 60 67

Grid Calculator centered on Last Chance with a lat long of:

  • 39� 44.441 North
  • 103� 35.615 West

Flight Systems:


Balloon Manufacturer Kaymont
Balloon Type latex
Balloon Size 1500 gram
Payload 12 lbs. (5 balloon sats) + EOSS payloads
Free Lift % 25%
Ascent Rate 1200 fpm variable. Probably leak resulted in steadily decreasing ascent rate until it finally went into a slow descent.
Descent Rate at cutdown ~ 1000 fpm sea level
Parachute 70 in. diameter (HM-2)
Peak Altitude 46,255.9 ft.
Launch Conditions dead calm

Data Files:

Arizona Near Space Research (ANSR)

Montana State (Borealis)

  • KD7MFJ-11

Edge of Space Sciences (EOSS-67)

Experimental Sub-Orbital Society (ES-OS)

  • KC�JHQ-11

Treasure Valley Near Space Program (TVNSP)

  • KD4STH-9
  • KD4STH-11
  • KD7HGS-11


N�KKZ Photos

N�LP Photos

KC0RPS's Photos


No audio recording were made for this flight.


From the Tracking Perspective

by Benj. W�CBH

Wow, what a great day.

Left at 4:30 am to pick up the driver and got back at around 5:30 pm.

We helped unload the helium bottles for the launch teams and we also watched KMark launch his mylar balloon. We left the site before the launch of the five latex balloons.

I had trouble with my computer and Nick's tracking program through most of the day. I finally gave up and just decided to use street atlas for the maps. Worked okay then.

Had a great talk with the owner of most of the land east of Agate. His brother-in-law owned the land where EOSS 67 landed.

I got his phone number and will try to add it to the list of people we know out east of Denver. Might come in handy someday.

Marty directed us to go to the aid of the Idaho team on their first balloon which landed southwest of Deer Trail. We went back that way, found the Idaho team and followed them to the proper road to get to their payload. Their computer was working all right and they found their systems without any help from the DFing antennas.

We then decided to head back to town and let my new driver meet some of the launch team. We had a great time talking with all of them until KMark's balloon finally decided to land. We then tore off west to help.

After many frustrating minutes of trying to find the proper roads, we got the landing grid point computed using Nicks grid calc program and off we went in search of KMark's payload which had become detached from his balloon which was skipping all over the countryside, with N0NDM and crew chasing it.

We finally found the signal after Larry K0ANI pulsed the commandable beacon and tracked it to a field full of vicious buffalo. Vicious things.

After a sizeable delay, the owner came down and allowed the rest of the tracking crew to go out and retrieve the payload. It took long enough for that to happen that Rick, N0KKZ and N0LP had time to come out and find the landing site and observe our methods of recovering payloads in dangerous areas. Ha! We even found a buffalo pie for Larry, N0NDM, who was still chasing the mylar balloon.

We had a great time at lunch in the cafe in Bennett. We met some new people and got to talk to the Idaho group. They live about 12 miles east of where I went to high school and college. I had a great time talking with them about Idaho. Haven't been back since my 30th high school reunion and next year is the 40th.

All in all my new DRIVER and I had a great time. We didn't get up on two wheels while making high speed turns, but that is okay. We had a good time, and learned some more about relaxing and listening for weak signals. Now, all I have to do is get my stupid computer to work so that I can read the packets as well as Chris. I did something different this time by mounting my dual band yagi in place of the single band yagi, and it worked well tracking signals on both bands. It also allowed me to communicate through a poorly responding repeater when I was in a bad spot. So, will have to add that to the permanent equipment list.

That's all folks. 

From the ES-OS Perspective

My my, what a day !

I'd like to extend a huge thanks to the EOSS gang and others that helped in the recovery of the "ES-OS" flight string. I thought it would be elementary as I got a position report from 100 feet AGL, but it apparently involved negotiating a yucca field inhabited by man-killing buffalo. The yucca did a number on my bottom package and completely discombooberated the "ChemSat" payload built by Adam's State College students. (Indeed, the trackers initially reported finding only an empty blue box.) Thanks to the EOSS trackers that back-walked the ~1/4 mile drag path to discover the debris field and recover the guts (I hope all) of the ChemSat. Meanwhile, the shredded bag took off and flew another 10+ miles at 0 to 3000 feet AGL. I had a two pound package on top of the balloon, but it just wouldn't tip over for three hours, finally landing at just past 3 pm.

The initial thought was that there was an electronic failure of the flight termination systems, but post flight inspection of the flight-termination balloon-top blow-plug revealed two burn marks about the size of a golf-ball. The electronics worked fine, but the blow plug refused to release. All the room temp testing of this system apparently didn't accurately mimic the environment the system encountered. That, or there was a rigging error. I'll dig into that later.

Although it was a long day, we all had fun.

Finally, extra special thanks to Larry and Dick for

  1. Hauling helium to the launch site and
  2. Helping us with the disposal chores for the 126k cu foot bag.


HF Radio

Bruce, NA�BR started the net at or about 06:15 local time (12:15 UTC) on 7.228 MHz. The band was not very cooperative. He moved about between there and 7.240 MHz looking for a clear piece of bandwidth. Propagation was not too good. Distant stations were heard but only sporadically.