EOSS-339/340 Metro State University - Intro to Space - Recap

Two 1500 gram balloons were launched from Deer Trail, Colorado at 0658 (EOSS-339) and 0716 (EOSS-340) on Saturday morning, April 22, 2023.
The balloons carried a total of 7 Metro State and High School payloads.

EOSS-339 rose to an altitude of 97,284 feet where it burst.  The payload string then landed about 15 miles south of Seibert, CO at 0910.
Latitude 39.0710, Longitude -102.7975, Altitude 4,768 ft -  120 yards east of CR-20 just north of CR-C.

EOSS-340 rose to an altitude of 92,029 feet where it burst.  The payload string then landed about 14 miles south of Seibert, CO at 0918.
Latitude 39.1118, Longitude -102.8602, Altitude 4,945ft -  3/10 of a mile east of CO-59 across from of CR-F.

Mileage link for club members  https://forms.gle/qJjy47iTHF5ywDPJ6

Original Announcement: 

One 3000g balloon or two 1500g balloons flying student payloads for Metro State University's Intro to Space Course.Predictions are available at www.eoss.org/predict. Deer Trail is the launch site.If cloud covers more than 5/10 the heavy will be configured into 2 1500 g balloons.


Event Date: 
Saturday, April 22, 2023 - 00:00 to 23:45
Flight Coordinator: 
Launch Site: 
Punkin Center: X 30, Y 30 Grid Test: N 39.000 • W 103.000: = X 67.5 Y 40.3


Metro State University Student launch.  One Heavy or 2 Lites launch site Deer Trail.


Balloon Type: 
Totex 3000g Latex
Rocket Man 12 ft
Payload Plan: 

Communications Plan

Preflight Net:

Confirmed: the 449.225 minus offset with a 141.3 Hz tone "Fun Machine” .  The Pre-Flight Net is on Fridays prior to the flights @ 19:00 (7 PM).

Analog T&R Repeater:

Confirmed: the RMRL 449.450 minus offset with 103.5 Hz tone for this flight, including Skyhub links to:

  • Limon (Cedar Point) - 447.650(-) MHz, 103.5 Hz
  • Hugo - 447.150(-) MHz, 103.5 Hz
  • Firstview - 447.600(-) MHz, 103.5 Hz
  • Akron - 447.425(-) MHz, 103.5 Hz
  • Stratton - 146.895(-) MHz, 103.5 Hz


RMHAM DMR has been approved using the “Wide” talk group.  This includes the use of both deployable repeaters.   


RMHAM has added the following DMR sites:

  • Burlington Colorado RMHAM-N0SZ Input 440.0500 MHz Output 445.0500 MHz Color Code 6,  TS-1 TG 700 (Wide), TS-2 TG 720 (Central)
  • Limon Colorado RMHAM-N0SZ Input 440.275 MHz Output 445.275 MHz Color Code 7, TS-1 TG 700 (Wide), TS-2 TG 720 (Central)

These two sites provide almost full coverage along the I-70 corridor from Byers to Goodland Kansas.

Updated code plugs are available on the RMHAM website.

The Usual EOSS Simplex Frequencies (UESF) will be used:

  • Ground Station                          446.050
  • Balloon #1 T&R                        446.100
  • Balloon #2 T&R                        446.150
  • Balloon #3 T&R                        446.200
  • Car to Car drive out                   446.275 

2M Direction Finding Frequencies:

  • 144.340
  • 144.905
  • 145.645
Tactical Calls: 
TacticalCall SignNameNotes
AlphaWAØGEH, KCØDMarty, Mark
DeltaKØSCC, KE0BMVStephen. Parker, Sunday Only if needed
FoxtrotKØNKKNancy (Flight Controller)
Ground Station (on wheels)N2XGL, K5JK, NoCALLJeff, Tom, Randy
TangoKCØLJohn (Remote From Texas)
TR Breakfast: 
Optional Tracker Breakfast, 6:00am, IHOP Limon, Flying J