EOSS-267 Fun Flight - Recap

Thanks to everyone that supported the EOSS-267 flight yesterday. It was a resounding success in several ways.  We shook the cobwebs off of our knowhow and  tracking stations, we successfully qualified several new payloads, and we had some new members join us in the chase!  We had several University of Colorado CBASE students join us for the launch and recovery to help hone their skills for assisting in planning, launch, and recovery later this year.

The weather was OK, except for the cold at the launch site, and the high wind at the recovery site.  It was better than dealing with the snow/freezing rain which was forecast but didn’t seem to make much of an appearance.  Thank you everyone for your flexibility in the date change.

KCØD-1 and wireless release #2

We had issues setting a new frequency in KC0D-1 before launch.  The issue was tracked down to a defective radio on the board.  That has now been replaced and the payload is now back up and working (and we are able to set the frequency!).   Tom’s (KE7KCK) GoPro mounted just below the release captured the successful operation of the new wireless release.  The microswitch that is activated when the release mechanism opens moved, so the report back was that the release did not open when it actually had. The battery inside of the release moved on impact at landing.  Both of these issues have already been addressed.  KCØD-1 and release #2 are now qualified and ready for the next flight.


This payload quit transmitting on the last flight. It was tracked down to a broken antenna cable.  Just to make sure that was all it was, this payload was flown and requalified.

KCØD-15 and release #1

This pair served as the ‘top’ beacon and release for the flight.  During this flight we tested the ability of the release to operate under full load, and under normal flight conditions.  This pair has flown many times and has automatically released the balloon after burst, but not under the full load of the flight string.  As hoped, it worked perfectly.  The balloon was manually commanded for release just above 65000 Ft. The on-board log file shows that the balloon was released at 65,462.  Not bad!

The successful release saved the trackers a long trek North of Sterling had the balloon gone to burst at around 95K feet.


This payload was not being qualified, but is a workhorse of the EOSS inventory.  It served as the ‘bottom’, which is the APRS beacon/digipeater that most trackers use to track the payload during flight.  As usual, it performed fine.

Again, thank you all for your participation and help

See you  mid-March for the next flight!

Mark Patton – KCØD

EOSS-267 Flight Coordinator

Original Announcement: 


Attention:  EOSS-267 flight date has changed to February 25, launch at 8:00 a.m. as a result of severe weather warnings for the recovery and launch sites.  Preflight net on 449.225 Saturday night, 8:00 p.m.

EOSS-sponsored flight to qualify new flight hardware for upcoming flights this year. One 1200g balloon.

A new payload and a new wireless release mechanism will be flown to qualify the pair for service later this year.  The wireless release will be commanded to open during flight, but is tethered to prevent the actual release of the balloon.  The KC7KCK GoPro will be mounted near the release to capture the operation of the release.  KC0D-11 will be flown to requalify the payload after a failure on the last flight due to a broken antenna connector.

 An attempt will be made to specify a target landing location of the flight string, then release the balloon at the right time to achieve this goal.  This could be useful to help avoid landing in undesirable locations such as a lake.

Prediction at www.eoss.org/predict Copy the prediction files for both 70K burst (EOSS 867)and the full flight at 100K burst (EOSS 267).  If the cutdown works, we will use the 70K version.  If the cutdown fails, we will use the 100K version.

The FAA Waiver and Authorizations can be found here.

Event Date: 
Sunday, February 25, 2018 - 00:00
Flight Coordinator: 
Launch Site: 
Rt. 71 & 14 (West) X 70 Y 30, test N41.000 W104.000: X=53.2 Y=56.8


Updated Payload Plan (Rev D).  As of 2/24

Multiple predictions on the prediction page (see flights 367, 467 ... 867) for different ascent rates and burst altitudes.

A 1200g balloon carrying EOSS beacons for qualification.

Balloon Type: 
Kaymont 1500g latex
9 foot Rocketman
Tracking Beacons
147.555 MHzKCØD-15APRS/DF/Wireless ReleaseSecondary Beacon
144.340 MHzAEØSS-12APRS/DigiPrimary Beacon, Timeslotted :00 & :30
145.600 MHz **change**KCØD-1APRS/DF/Wireless Releasefor qualification with tethered release
145.750 MHzKCØD-11APRS/DF/Releasefor qualification without release

Preflight Net:

  • 449.225 MHz RMHAM Repeater (141.3 Hz Tone) 8 pm MDT preceding night
  • 146.940 MHz (103.5 HZ Tone) RMRL Repeater if the RMHAM machine is down
  • 146.640 MHz (100 Hz Tone) DRL will serve as a backup frequency

Recovery Operations:

  • 449.450 MHz RMRL (103.5 Hz Tone)
  • 448.225 MHz (141.3 Hz Tone) Testing… PL verified 7/2/14
  • 446.100 MHz Field Simplex
  • 146.550 MHz Backup field simplex

Launch Site Simplex: 446.050 MHz

HF - Possible ops: 7.235 LSB

Tactical Calls: 
TacticalCall SignNameNotes
AlphaWAØGEH, KCØDMarty, MarkTracking Coordinators, Downrange
BravoKE7KCKTomTracker, Downrange
CharlieKCØRPSJimTrackers, Launch to Recovery Site
DeltaKØSCCStephenTracker, Launch to Recovery Site
EchoKDØSEMDaveTacker, Launch to Recovery Site
FoxtrotN6BAJeffTracker, Downrange
GolfNØNDMLarryTracker, Launch to Recovery Site
HotelKEØORBJon, NancyTracker, Downrange
IndiaW9CNMikeTracker, Sunday Only
JulietKØLOBJim, JanaeTracker, Downrange
KiloC-BASE Students Bryan, Antoni, Anshi, Colin, JacobTrackers, Downrange
TR Breakfast: 
As of Friday afternoon it looks like the tracking breakfast will be at McDonalds in Brush, CO Time 06:15 - 07:15. We will be cutting down at 70K, thus the shortened flight.