EOSS-284 Spring STEM Flight - Recap

Original Announcement: 

Due to adverse weather conditions in the recovery area, the launch is postponed until 3/24.  Payload plan Rev D posted - the only change is to the launch date.

3/22/18: Updated Grid

The launches are scheduled for 7:10am from Deer Trail School in Deer Trail Colorado. This link shows maps and directions to get to the site. Payloads should be there no later than 6:00am. Note that it is over a one-hour drive from Boulder and almost a two-hour drive from Colorado Springs to the launch site.

Predictions of the flight path and launch site weather are available here. The prediction updates daily by noon. You can watch the prediction change. Please keep monitoring this page for changes. If the winds change, we may have to move the launch site.

1 1500g balloon

  • NDIA-sponsored STEM experiments from six schools
    • St. Mary’s High School (Nuclear Chemistry students)
    • Texas Middle School (8th grade science students)
    • Casey Middle School (Raspberry Pi computer programing students)
    • Fremont Elementary School (4th grade students)
    • Evans International Elementary School (4th & 5th grade students)
    • Schriever AFB Child Enrichment Center (K - 4th grade students)

The mileage link for EOSS members is   https://goo.gl/forms/V7r4DKZyEpod5auj1

Event Date: 
Sunday, March 24, 2019 - 00:00
Flight Coordinator: 
Launch Site: 
Punkin Center X=20, Y=30, Grid Test N39.000 W103.000 Ans: X=57.5, Y=40.3


A balloon carrying three student experiment payloads and a geiger counter.

Balloon Type: 
Totex 1500g latex
10 foot spherachute with fast release and thermal cutter
145.535 MHzKC0D-1APRS/DF/Cuttersecondary beacon
145.710 MHzKC0D-2APRSQualification
144.340 MHzAE0SS-7APRSprimary beacon

EOSS Preflight Net @ 8 PM MDT preceding night:
        • 449.225 MHz (-5 MHz Offset, 141.3 Hz Tone )  RMHAM Repeater  
        • 146.940 MHz (-600 KHz Offset, 103.5 Hz Tone) RMRL Repeater if the RMHAM machine is down
        • 146.640 MHz (-600 KHz Offset, 100.0 Hz Tone) DRL Repeater will serve as a backup to the backup repeater 

Launch Site:
        • 446.050 MHz Simplex  
        (Note that some radios assume these are repeater frequencies and attempt to put a 5 MHz offset in the transmit frequency automatically)

Track & Recovery Operations:
               • 448.450 MHz (-5 MHz Offset, 100.0 Hz Tone) PPFMA repeater (Assuming we are flying out of Deer Trail).

        Simplex Frequencies:
        • 446.100 MHz Balloon #1 Field Simplex 
               (Note that some radios assume these are repeater frequencies and attempt to put a 5 MHz offset in the transmit frequency automatically)

        Legacy 2M Simplex Frequency (not generally used due to desense/interference issues with the 2M APRS packets)
        • 146.550 MHz Simplex

2M Direction Finding Frequencies:

  • 144.340
  • 144.360
  • 144.905
  • 145.045
  • 145.535
  • 145.645
  • 145.710
  • 145.765


Tactical Calls: 
TacticalCall SignNameNotes
AlphaWAØGEH, KCØDMarty, MarkAlpha Team
CharlieKCØRPS, W0GVJim, JerryTrackers
FoxtrotN6BAJeffTracker, SDR Whiz
Ground StationN0LPNickGround Station
HotelKE7KCKTomFC, Launch, Tracker
KiloN0NDMLarryLaunch, Tracker
TangoKC0LJohnTracker From Texas
TR Breakfast: 
IHOP 2495 Williams Ave, Limon, CO 80828. 6:15 Caution, the Limon area will be rainy Friday and Saturday morning. Sunday should be a dry day, but the roads will be muddy. Be safe on muddy roads. Prediction: X=65.0, Y=67.2 7.5 miles north of Seibert