EOSS-253, 254,255,256 COSGC DemoSat and BIRST Flights - Recap

EOSS-253, 254, 255, and 256 were launched in rapid succession starting at 0700 from the Limon Softball fields launch site on July 15, 2017.  All were 1500g exempt balloons.  

  • EOSS-253 reached an altitude of 98,885 ft
  • EOSS-254 reached an altitude of 100,795 ft
  • EOSS-255 reached an altitude of 97,847 ft
  • EOSS-256 reached an altitude of 96,219 ft

All payloads were recovered north of Matheson, CO.  Video of the EOSS-255 and 256 Launch videos can be viewed on Youtube here: EOSS-255 Launch ; EOSS-256 Launch

Recap galleries have been created below.  Check back for updates to Charts, data and photos as they are loaded.  

EOSS thanks local landowners for permission to recover the Colorado Space Grant and Ball Intern payloads.

 Mileage Reimbursement 


Original Announcement: 

Update Friday 1430:  253 lite and 254 lite payload plans changed to Rev C - swapped COSGC payloads to make exempt weight. Cloud cover forecast is > 5/10ths, so be prepared to split onto lite balloons, and pay attention to which balloon you are on to get  you to the right recovery (noted on plans).Launch site has changed to LIMON.   There has been heavy rain in the area, and forecasted storms in the afternoon.  So be prepared for possible rainy and muddy conditions. Take extra care while driving on the back roads. Hopefully we will recover before the afternoon weather.  Note below that our repeater frequency will be 448.450 Mhz. This will be two flights to support the Colorado Space Grant Consortium summer program and the Ball Aerospace BIRST intern program.  The nominal configuration will be 2 3000g balloons.  However, if cloud coverage precludes non-exempt flights, we will split the payloads and fly 4 1500g balloons to meet exempt requirements.  Predictions are located here. In the case of greater than 5/10ths cloud cover, we will split the strings into exempt strings.  See below for contingent 'Lite' payload plans.

Event Date: 
Saturday, July 15, 2017 - 00:00
Flight Coordinator: 
Launch Site: 
Punkin Center, X 80, Y 20, Test N 39.0000, W 104.0000  X 64.0 Y 30.2


EOSS-253 will be a 3000g balloon in support of the COSCG Summer DemoSat Program

Balloon Type: 
3000g Totex
10 ft.
147.42 MHzK0SCC-11APRS/DF/Cutter
144.34 MHzAE0SS-12APRS/DF/Digi


This will be a flight of a single 3000g balloon in support of the Ball Aerospace Intern BIRST program

Balloon Type: 
10 ft.
144.95 MHzKE0BMV-11APRS/DF/Cutter
144.34 MHzAE0SS-13APRS/DF/Digi
144.36 MHzKC0D-15APRS/DF/Releaseunder qual
145.60 MHzKC0D-14APRS/DFunder qual

Preflight Net:

  • 147.225 MHz CRA Repeater (107.2 Hz Tone) 8 pm MDT preceding night
  • 146.940 MHz (103.5 HZ Tone) RMRL Repeater if the CRA machine is down
  • 146.640 MHz (100 Hz Tone) DRL will serve as a backup frequency

Recovery Operations:

  • 448.450 MHz PPFMA (100.0 Hz Tone)
  • 448.225 MHz (141.3 Hz Tone) Testing… PL verified 7/2/14
  • 446.100 MHz Field Simplex EOSS #253
  • 446.150 MHz Field Simplex, EOSS #254
  • 446.200 MHz Field Simplex, EOSS 255 (if necessary)
  • 446.275 MHz Field Simplex Driveout and EOSS #256 (if necessary)
  • 146.550 MHz Backup field simplex

Launch Site Simplex: 446.050 MHz

HF - Possible ops: 7.235 LSB

Tactical Calls: 
TacticalCall SignNameNotes
AlphaWAØGEH, KCØDMarty, Mark, Wyatt, CashEOSS #253, 255, Alpha
BravoW9CN, KBØYRZ, N0JPSMike, Chris, JohnEOSS #254, 256, Alpha Backup, Trackers
CharlieKDØSEM, KE0CQQDave, RyanEOSS #253, 255
DeltaKØSCCStephenEOSS #254, 256, Launch Team, Tracker, Rider?
EchoKE7KCKTom, ConnerEOSS #254, 256, Flight Coordinator, Ball
FoxtrotKCØRPS, WØNFWJim, GeorgeEOSS #253, 255, Tracker
GolfKCØLJohnEOSS #253, 255, Tracker From Texas
HotelN7JJYGeorgeNew Tracker, Follow Foxtrot Tracker
IndiaKØLOBJimEOSS #253, 255, Tracker, Welcome Back!
WhiskeyKDØNRYChrisEOSS #253, 254, COSGC Director
TR Breakfast: 
Grid Test Changed Friday night to provide answer of 64.0,30.2 Launch site was changed from Windsor to the Limon Ball Fields. First launch is at 6:45 unless a 2fer indicates otherwise. Trackers who do not wish to travel to the launch site (this prediction is west of the launch site) may meet Mike, Chris and John at Patty Anne's Cafe in Kiowa, about 6:00. The forecast looks a bit iffy for cloud cover, so everyone be sure to familiarize yourselves with the "lite" payload plans for a 4fer. The Tactical Calls and Note section below has been modified to designate EOSS #255 and #256 in case of a 4 flight day. Limon has had some heavy rain, so be aware of slick roads and drive safely. This from Randy: The area in and around the predicted landing site for EOSS253/254 received 1-2" of rainfall in the past 24-36 hours, so be advised that driving conditions on unpaved roads may require some caution, as will any excursions off of the roadways and into the fields. The grid has been posted above.