FLIGHT RECAP OF EOSS-23

Air Force Academy Test Flight

LAUNCH DATE: 21-May-1995
LAUNCH SITE: Air Force Academy Parade Grounds
Launch coordinates:

  • 39'00.56 N
  • 104'52.90 W
  • 38 deg 50.98' N
  • 103 deg 26.94' W

LAUNCH TIME : 12:15 UTC
FLOAT START TIME: 13:58 UTC
CUTDOWN TIME: 19:31 UTC
TOUCHDOWN TIME: 20:12 UTC

FLIGHT TRACK: 99 degrees azimuth
FLIGHT EXPERIMENT: Satellite Test
PROJECT INTEGRATOR: United States Air Force Academy - Gil Moore
Shuttle I FREQUENCIES:

  • 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.
  • Cross Band Repeater (Courtesy of the Rocky Mountain Radio League see note at bottom of page):
    • 446.000 MHz FM Input Frequency
    • 147.555 MHz FM (250 milliWatt output) Output Frequency
  • ATV:
    • 426.250 MHz AM (1 Watt output) -NTSC video
  • Pikes Peak FM Association 448.450 MHz
  • Cross band Repeater on EOSS-23 (446.000 input, 147.555 output)

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Flight Recap:

I originally indicated that this satellite would fly on board the Space Shuttle. That is incorrect. It will in fact be launched aboard an expendable launch vehicle.

The Academy's satellite measures approximately 18" on a side. It is equipped with solar panels and is outfitted with an attitude control system. This balloon flight will be a test of that attitude control system's ability to keep the satellite oriented on the sun using a solar sensor.


satellite being prepped for launch.

 

Gil Moore was the lead project integrator for the Academy.

As can be seen in this photo, he was quite please at the prospect that we would finally get his payload off the ground. The photo was taken just before dawn. Weather conditions were ideal and the satellite payload was breezing through its preflight checkout.

 


Filling of the 250,000 cu. ft. Raven balloon

 

The launch was spectacular if uneventful. The winds were calm and the balloon with its payload train rose calmly into the skies over the Air Force Academy.


Lift off of EOSS-23

 

Once the balloon entered float it hovered between 113,000 feet at a max altitude and 95,000 at a minimum altitude. The average altitude throughout the float period was 98,615 feet above sea level. The payload was commanded to cut itself down and at landing the duration of the entire flight was about 8 hours.

This flight produced a brand new (to me) graph. Normally EOSS does not fly zero pressure balloons. Here is the Altitude versus Time Graph for EOSS-23.

 

Also of possible interest is this graph depicting the Ground Track of EOSS-23. It depicts the changing winds at altitude. These direction changes were happening WHILE the balloon was floating at altitude. They are not a result of traversing differing levels of the atmosphere.

EOSS flew a crossband repeater to assist the tracking and recovery teams. We invited remote stations to use the repeater under the direction of net control.

The Academy flight was entirely their work. They offered EOSS payload space (we tie onto their support cable) in exchange for our recovery efforts.

Files

If you're interested in the full telemetry from this flight click here to download EOS23TLM.ZIP, a 47K zip file. Included in this file is an ASCII delimited file suitable for import into a spread sheet, should you wish to run some calculations of your own.

Note:

If you are perusing the pages and come across a glaring omission, PLEASE email me about it so I can give credit where credit is due. Amateur Radio operators get paid little (actually folks it's NOTHING) for their long hours on these projects. If I can properly bestow some kudos, I WANT to do it.

Thanks!!