Flight Recap of EOSS-11

Launch date: April 4, 1993
Launch time: 17:51 UTC (flight a), 19:23 UTC (flight b)
Launch site: Robert Clement Park
                   Littleton, Colorado  USA
Launch coordinates:  39.60865 deg NORTH
                              105.07388 deg WEST
Max Altitude: 98,000 ft.
Burst Time: 20:38 UTC
Touchdown time: 21:40 UTC
Touchdown Distance: 47.9 miles

Touchdown coords are WAY OFF and incorrect. They've been posted here for 15 years so I'll leave them for web based historical interest but replace them with correct coords if they someday become available, probably not.

Touchdown coordinates:  38.5351 deg NORTH
                                     103.5471 deg WEST

Payload Systems:

  • W6ORE Flight Controller
  • ATV - 426.250 MHz
  • Beacon - 147.555 MHz
  • Pressure Sensor used to determine altitude
  • Temperature sensors (internal and external)

Experiments: Test flight of LORAN-C
Project Lead: Jack Crabtree, AA0P
Balloon Lead: Merle McCaslin, K0YUK
Tech Committee: Mike Manes
Launch Site Lead: Jack Crabtree, AA0P
Ground Station: Rick von Glahn, N0KKZ
Tracking and Recovery: George Riedmuller - N0NJM and Paul Ternlund - WB3JZV

Flight Highlights
The first flight (11 A) was aborted due to insufficient lift caused by an old balloon (manufactured in 1981). Filling nozzle broke and we lost some helium. Compounding the erroneous lift readings, high winds at the launch site. The balloon never raised it's payload over 10 feet altitude before it took off in the wind lowering and dragging its payload across the ground, a busy (luckily it was a low traffic day) road and finally onto a golf course where it hung up in some fencing. The external temperature sensor and the 35mm camera suffered damage enough to make them fail prior to the second attempt (11 B).

The second flight used a new balloon (manufactured in 1992). Using an increased tare weight we had a normal high wind launch.

Other than very windy conditions, the day was CAVU.

The LORAN-C lost lock a good part of the flight. The altitude sensor worked normally, it still needed calibration at high altitudes though.

The computer delivered a false touchdown signal at 17,000 feet. Bob, W6ORE made a software fix for the next flight.


Tracking and Recovery Perspective on EOSS-011

by Jim White, WD0E

A slightly longer unedited (by the webmaster) version is available at YOUTUBE HERE