Flight Recap of EOSS-2

Launch date: March 11,1991
Launch time: 16:03 UTC
Launch site: Robert Clement Park
                   Littleton, Colorado  USA
Launch coordinates:  39.60865 deg NORTH
                              105.07388 deg WEST
Max Altitude: 111,000 ft.
Touchdown time: 18:28 UTC +- 5 minutes
Touchdown site: Near Ted's Place, Colorado USA (yep, it's a town nw of FT. Collins)
Touchdown Distance: 74.31 Miles
Touchdown coordinates:  40.6833 deg NORTH
                                     105.1500 deg WEST

Payload Systems:

  • ATV - 426.250 MHz
  • Beacon - 147.555 MHz
  • 6 meter control of ATV pointing angle
  • Pressure Sensor used to determine altitude
  • Temperature sensors (internal and external)

Project Lead: Jack Crabtree, AA0P
Balloon Lead: Merle McCaslin, K0YUK
Launch Site Lead: Jack, AA0P
Public Relations Lead: Tim Armagost, WB0TUB
Tracking and Recovery: Greg Burnett, K0ELM
Radio Nets Lead: Eileen Armagost, WD0DGL

  Flight Highlights
ATV picture looked ok after launch. We were able to control the camera attitude right after the launch. This was the first time we were able to look up at the balloon and out at the horizon. We lost the RC of the ATV camera after a few thousand ft. No Pictures from 35mm camera. The explosion of the balloon tangled the parachute, and the package came down hard. Some of the parts of the flying balloon were recorded on ATV.

The beacon stayed with the package and we found and recovered the payload within 45 minutes of touchdown.

We used an AIR (Atmospheric Instrumentation Research) altitude/temperature module to downlink on the ATV audio subcarrier.

Weather conditions at the launch were ok. We had moderate winds and so, used a plastic cover over the balloon to control it's bouncy movement. However a fairly large static charge dissipated when the plastic was removed. We didn't take any static hits on the payload but it was a concern.


Dave Clingerman, W6OAL, at the workbench getting the payload into shape.


Clement Park Launch site preparations underway


Here's now we used to launch. Rather than lining up the payload handlers downwind and releasing the balloon, we used to "lower" the balloon into the air by hand until the entire payload train was being held by the last paylaod. That was released and we had a launch.

Recap of EOSS-002

by Robert Slate, N0TQN

webmaster note (09-Sept-07): Slate sent this in to me several months ago but I seemed to let it fall off my radar. Sorry about that. A recent email passed across my desk and reminded me to get to work.

Click HERE or on the Image to see a full resolution version

While I had listened and "tracked" EOSS-001 with a handi-talky using body shielding methods, this was the first flight we chased. I did not have my license at the time so while I could listen to the chase teams, I could not talk to them.

As I recall, we all were surprised when it went north and there was fear of it landing in the mountains. We were not planning on chasing but I grabbed the family and chased from I-25 and HWY-14 to about the hog-back on HWY-14 where we lost the signal.

The chase for us started at about burst and it became apparent pretty soon that it was coming down rather fast!

Somewhere around the north end of Horsetooth I found the team and lead them up into Bonner Peak Ranch where Crystal (our daughter) first spotted the balloon and payload.

We were last in the chase and everyone else had sped on past it. Since I could not contact them we just waited until they all came back.

This photo was taken with an cheap instamatic and then later copied with a modern digital camera. Text was then added.

Of note, maybe because of exposure to the EOSS and DSES, Crystal has since pursued a degree in mechanical engineering and has worked for several years with NASA and Boeing on flight hardware for the ISS.