Flight Recap of EOSS-20

note: This synopsis has been reconstructed using telemetry logs and my personal memory. Uh, oh. Any errors are mine and if discovered will be corrected.

Launch date: December 3, 1994
Launch time: 17:30 UTC
Launch site: United States Air Force Academy
              Colorado Springs, Colorado  USA
Launch coordinates:  39'00.56 N
                               104'52.90 W

Last Packet time: 19:38 UTC +- 5 minutes
Last Packet coordinates:  39'00.92 N
                                      103'23.65 W
Last Packet bearing from launch: 90.2 degrees
Last Packet distance from launch: 79.8 Statute Miles

Maximum Altitude: 95,000 feet est.

Payload Systems:

  • ATV - 426.250 MHz
  • Beacon - 147.555 MHz
  • Telemetry - 144.290 MHz
  • Pressure Sensor used to determine altitude (AFA provided experiment)
  • Temperature sensors (internal and external)
  • GPS position determining receiver


  Flight Highlights


This flight had a dual purpose for the Air Force Academy Cadets. First, to expose the Cadets to the real world of contractor/contractee relationships. Second, to fly an altitude sensor experiment onboard the payload.

EOSS was also using this flight as a test of their new Shuttle II payload system.

What's that expression, "Into every life a little rain must fall." Well, we got poured on for this one. But, experimentation does often produce results not expected.

Very briefly, our new controller had a few problems. Timing of port access caused some lost data. A possible desense onboard caused some commands to be lost. We lost GPS lock at 64,000 feet. It seems we received incorrect firmware for the GPS board. On descent we lost first, the beacon. Oh, it continued to transmit, however, it was in freefall making its way to earth separately from the payload. It ended up landing some 20 miles from the touchdown site for the rest of the package. A plastic strap that attached that beacon to the payload train had flown over 8 flights. It's believed that UV weakened this strap and caused it to snap under heavy loads produced during the initial and turbulent descent phase. During that same turbulent passage, we lost our ATV antenna and the accompanying picture vanished at net control.

We were lucky that we carried a secondary payload from NAVSYS. Their TIDET package, transmitting on 403 MHz was what lead our Fox hunter teams to the payload.

FAA Liaison for the flight as well as technical assistance was performed by Mike Manes, W5VSI. 

The balloon preparation team headed by Merle McCaslin, K0YUK, ran into a few interesting problems. High winds at launch time caused a wrist watch's sharp pointed edge to come into contact with the balloon. POP!

After this setback, the balloon prep team moved to an area of relative shelter for inflation.

Once the balloon was ready to go, a track team was required to keep the payload train from hitting the ground as the balloon ascended to the full length of its train.

The fox hunters were up to their usual standards. Recovery of the payload was effected in a timely fashion.