Announcement of EOSS-31

note: The original announcement for this flight was lost. This is a recreation compiled on 18-March-2005. the recreation was prompted by the recent submission by Marty Griffin, WA0GEH, of documents pertaining to the flight.

LAUNCH DATE: September 20, 1997
LAUNCH TIME: 14:00 UTC, 08:00 MDT
LAUNCH SITE: Windsor, Colorado (Gene Fatton's Ranch - Here's a Map


  • 40deg 28.493' North
  • 104deg 57.756' West Longitude


  • East


  • EOSS Cutdown mechanisms
  • APRS Experiments


  • 147.225 MHz Colorado Repeater Association (Thanks)
    • Preflight Foxhunter Net 8:00PM the preceding night

Launch Site:

  • Simplex 146.550 MHz


  • 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.


  • 147.555 MHz
    • Primary beacon for the Tracking and Recovery Team

ATV: (weight contingent)

  • 426.250 MHz AM (1 Watt output) - NTSC video
    • EOSS Shuttle Video

Tracking and Recovery Teams:

  • 449.450 MHz Rocky Mountain Radio League Repeater
    • WA0GEH Field Coordinator
  • 146.58 MHz Simplex Field Frequency

HF Net:

  • 7.235 MHz no net control set as of this writing


Automatic Position Reporting System (APRS):

EOSS Shuttle controllers now beacon on the packet telemetry frequency with an APRS position string. If you are running APRS you should be able to graphically track the progress of the flight on the "CODENVER.MAP" map file. The Shuttle is not a TNC equipped packet station. It only reads data from various sensors and experiments and formats and transmits that data in AX.25. Therefore, beacons from other APRS stations will NOT be retransmitted (digi). So, in order to minimize possible interference with hams in your area, we request you turn off the position beacons at your APRS station. Thanks!


The Amateur Video Signals from the payload may be picked up by a cable ready TV set on channel 58. However, you need to be very close to the balloon, and have a directional antenna to do this as cable receivers do not have much sensitivity (why should they?). If you don't have a cable ready set, try tuning DOWN from UHF channel 14. Some sets can receive the signal there too.

Who Can Hear It:

Almost all our transmitters are on VHF or above frequencies. Therefore, you need to be line of site to the payload to hear/see it. Since the payload rises to an altitude of over 90,000 feet on most missions, reception is usually possible for folks in most of Kansas, most

of Nebraska, most of Wyoming, extreme south eastern Idaho, eastern Utah, north eastern Arizona, most of New Mexico, northern Texas, and western Oklahoma. DO NOT BE DISCOURAGED by the apparent low power of our signals. I usually monitor the Beacon with an HT from the ground station throughout the flight. The signal is strong even at 130 miles and I only lose it when the balloon descends below my horizon.

Marty's Email

I include this email as it is the original preface to the above announcement as it was distributed to various news groups, and email lists.

-----Original Message-----

From: Marty Griffin
Sent: Thursday, September 18, 1997 11:25 AM
To: ''
Subject: EOSS 31 Flies Saturday!

Hi Folks,

The Edge of Space Sciences will fly EOSS 31 this Saturday from Windsor Colorado. Launch time will be 8:00 and there will be assorted signals on the amateur frequencies.

EOSS 31 will be a contest of sorts. Since we need a reliable cut- down mechanism for EOSS 33, we will fly as many cut-down mechanisms as members can build. There was some discussion about using a pager service for the cutdown signal. Chip volunteered to investigate a simple "kitchen timer" concept.

For more details see our web page: (webmaster note: no longer valid)

Here are a few details:

Flight Profile for EOSS-31

LAUNCH DATE: September 20, 1997
LAUNCH SITE: Windsor, Colorado (Thanks to Gene Fatton, Gene will host a brunch for the visitors, launch crews and recovery folks, life doesn't get better than this!)

EOSS #31 is on schedule and will launch from Windsor, Colorado at 8:00 am MDT. Listen for the beacon on 147.555 and look for ATV on 426.25. The flight should reach 90,000 ft. and the beacons should be heard in a 400 mile radius. This flight is carrying experiments for EOSS members to try various cutdown mechanisms as well as some APRS experiments.

Friday night, Marty, WA0GEH will conduct the tracking and recovery net on 147.225, 8:00 MDT. Logistics for the tracking and recovery operation will be discussed. Please plan to listen in or, if you are interested, joining the effort. Greg, N0ELM is the EOSS Tracking and Recovery leader and will be on the net.

The Tracking and Recovery net will be on 449.450 MHz Saturday, September 20. Starting about 6:00 am logistic traffic will start to flow. This will be become a DIRECTED net, all traffic for the recovery effort will be directed through Marty, WA0GEH.

We hope to see some of the students from Creighton Middle School at the launch site. We are looking for some schools who are interested in participating in future flights. If you know of a possibility, please f orward this email to that person and have them contact Marty Griffin, 303-220-7225/303-470-5471h.

Again, the instructions for getting to the launch site, (thanks to Ted, N0RQV):

1. Travel !-25 north to exit 262 (Windsor) 2. Exit, travel east 1.5 mi. to a road with no sign, but has power poles. 3 Turn south, travel 0.4 mi to the launch site, a barn on the east side of the road.

Visit our Web Page at:

webmaster note: the above URL was the original home of the Eoss Web site. I left it in for nostalgic and historical purposes. It no longer exists and clicking on it will only take you to the new domain name holder's advertisement page.