Flight Recap of EOSS-26

LAUNCH DATE: April 6, 1996
LAUNCH SITE: Moved to: 2 Miles East of Punkin Center, Colorado

  • 38deg 50' 38.4 North Latitude
  • 103deg 39' 47.3 West Longitude



Landing Time: 19:53 UTC, 12:53 PM MST (approx)

  • 38deg 13.59' North Latitude
  • 103deg 42.12' West Longitude
  • Bearing from Launch Site: 183 Degrees
  • Distance from Launch Site: 42.6 Miles

FLIGHT EXPERIMENT: Gas Capture Experiment and In flight Ozone Experiment
PROJECT INTEGRATOR: University of Colorado at Colorado Springs and Air Academy High School


  • Preflight Foxhunter Net 8:00PM the preceding night
    • 147.225 MHz Colorado Repeater Association
  • Launch Site:
    • Simplex 146.550 MHz
  • Telemetry:
    • 144.340 MHz FM (1 Watt output) - The Packet telemetry stream is in ax.25 format at 1200 baud and is readable in plain English for the most part. Included in each telemetry frame is an APRS position string (APRS users see note below). Every few minutes a CW ID is transmitted on this frequency.
  • Beacon:
    • 147.555 MHz beacon only (due to the rush, confusion, and high winds, it wasn't turned on)
  • ATV:
    • EOSS Shuttle Video - 426.250 MHz AM (1 Watt output) - NTSC video
  • Foxhunters:
    • 448.450 MHz Pikes Peak FM Association Repeater
    • 146.58 MHz Simplex Field Frequency
  • HF Net:
    • 7.235 MHz no net control set as of this writing

Recap of the Flight:
Click on Pictures for hi-rez versions

At 0:dark:30 teams of foxhunters roused themselves from a brief nap and hit the road in search of a payload. In their minds, a worry about the path this payload might follow.

The previous evening the winds aloft reports indicated a path of approximately 195 degrees from the launch site over a distance of 45 miles. This track would be a violation of EOSS policy to avoid, if at all possible, populated areas. But, 12 hours is often an eternity in wx in Colorado, and it was hoped that the morning's reports would bring a more palatable prediction.

Unfortunately, change was not in the wind. And so, with a nearly identical prediction as the previous evening, it was decided that the only safe way to fly was to move the launch point out east.

The thriving metropolis of Punkin Center, Colorado was determined to be a viable location for launch. And so, the launch team packed their bags and hit the road.


A delay of 2 and 1/2 hours was taken in order to give the launch team sufficient time to move to the new location and set up operations.

Payload integration between the EOSS Shuttle I (on top, gold) and the UCCS/AAHS (sliver) was accomplished with no troubles.

While we had ensured a safe flight path, the delay had given the surface winds a chance to act up and disrupt our preparations. Winds at the launch point were a steady 8 to 10 mile per hour with gusts up to 16 MPH. These conditions made launch preparations a nightmare. As seen in this picture, our pilot balloon was being dragged into a nearly horizontal position relative to its tie down point by the high winds.


Filling operations nearing completion.


As seen here by the 45 degree angle of the parachute pointing towards the balloon, Merle really had his hands full. The balloon was being forced dangerously close to the ground by the high winds. While launching in these conditions is possible with a nice open field, here we were on a narrow county road with two barb wire fences on either side. Thankfully, the winds were almost directly out of the north, and we did have a good runway to get the payload airborne.


With a little good timing and a few hardy track stars, we did manage to launch the balloon.
Flying is fun
Once airborne we checked out the various frequencies and to our angst, discovered that somehow, the beacon had not been activated. With all the tension at the launch site, it's a wonder we got this baby airborne at all, but, with dozens of people monitoring HTs, a checklist being completed the frustration at this oversight was palpable.


In spite of all the difficulties encountered during the launch, the crowd seemed to enjoy the liftoff experience. We had a large contingent of students from the schools involved and there were numerous spectators who had learned of the event via amateur radio, and perhaps from this web site.

The Students of the Air Academy and the University of Colorado at Colorado Springs conducted two experiments.

The Gas Capture experiment utilized a mechanical device to capture an atmospheric sample several thousand feet above the launch site. This device consisted of an evacuated canister with a valve controlled by radio. When the balloon rose to the sample altitude, a command was sent that toggled the valve open and closed. The canister was successfully filled with a sample and sealed.

The on board ozone sensor operated throughout the flight. Measurements from this experiment were transmitted to the ground station via the Shuttle's Computer and radio suite. The telemetry file (available here in a ZIP file) is in plain ASCII format.


During the flight students from the Air Academy High School manually entered this data (as seen here - computers out of sight, sorry) into an EXCEL spreadsheet for processing to determine the ozone concentrations from the data beamed to the ground.

Throughout the flight the Tracking and Recovery Teams were active DFing the payload. Their experience at this task is readily apparent. Many times their triangulated bearings matched to within a mile or two of the GPS determined position of the payload.

Due to the phenomenal skills, and incredible guesswork of the preflight weather team <g> with a predicted touchdown of 44.5 miles from the launch site at 188 degrees, the hunters had little work to do. One team merely drove to a location near this predicted site and waited. And for their wisdom, they actually got to see the payload land.

Hey, you'll never guess who does the weather, right??

But seriously, we usually don't get half this lucky with predictions over Colorado. The weather here can be somewhat changeable. A team is always located in the vicinity of the predicted touchdown and this time that team got lucky. And although they did have that fantastically accurate prediction, they were really guided into their position by the number crunching guys at Tracking and Recovery Net control.

And so, recovery proceeded apace. Minutes after touchdown the lucky team was eager to romp off to the payload and make the recovery. However, we do have a safety policy that required them to wait until a second team was on site to man the radios while they trekked into the touchdown point. They were good sports and bided their time.

Another flight successfully concluded. And EOSS would like to thank:

  • The Pikes Peak FM Association for their fantastic repeater system, in particular, the 448.450 MHz repeater and it's linked cousins. This baby really makes chasing in south eastern Colorado a pleasure. Thanks to their members too, for putting up with all the chatter.
  • The supporters of the Multinational Oil Conglomerates, our FOX HUNTERS. Banks will be calling in loans for your gas charges soon so, be prepared. Thanks guys. Your perseverance and expertise make EOSS a viable concern. Somehow, I don't think the membership would be willing to bear the costs of one lost payload after another. And you guys and gals have managed the incredible feat of recovering 26 payloads in a row. The perfect record continues.
  • The Students. I now know what dedication is. I watched these folks slave themselves to their computers and manually enter every datapoint as it arrived via telemetry. WOW! Just imagine, every 30 seconds you gotta enter that data. Fall behind and you could really lose it. But, these stalwart souls banged away successfully and compiled the database without a hitch. But, these intrepid souls were not the only students involved. 
  • Read about all the teams in a report the students submitted to EOSS to help us get up to speed on their project.
  • And Many More!

And one special kudo. Thanks to the Pikes Peak Radio Control Club for the use of their incredible facility. Not only do they offer all the comforts of home, they entertain you while you're about your tasks.

This gentleman, sorry I didn't get your name, flew this beauty through all (or at least most) of the aerobatics routines. Hammerheads, rolls, you name it. What a show.