EOSS-274 GPSL Launch - Recap

EOSS-274 with two KC0D payloads on a qualification flight, two GPS-equipped radio beacons, and a 10 ft. Rocketman parachute with at total weight of 10.11 pounds was launched on a 1200 gram balloon from Homedale, ID  (N43° 36.84', W116° 5.27') at an elevation of 4,062 feet, and within a few yards of the Snake River, at 07:52:10 AM MDT on June 16, 2018.  The launch was part of the GPSL 2018 mass launch.  The last packet received before balloon burst was at 12:30:40 PM at an altitude of 92,413 ft. after an ascent averaging 559 ft./min.  The maximum recorded speed was 115 mph at 9:48 AM at an altitude of 34,004 ft. on ascent.   The parachute and flight string touched down at 2:15 PM at N44° 5.73', W115° 30.24' at an elevation of 5,800 ft. after a flight lasting 3 hr. and 21 min.  The horizontal touchdown speed was about 1 mph and the vertical speed was 710 ft./min.  The touchdown point was about 5.5 miles east of the town of Lowman, ID (N44° 4.939', W115° 336.712').  The straight line distance between launch and touchdown was 78.2 miles.

 A video of the pico balloon preparation and launch at https://www.youtube.com/watch?v=_RVhlBpa1k0

Original Announcement: 

EOSS Flight Predictions are updating daily (around noon) at www.eoss.org/predict

Payload plan updated to Rev 6

We'll be attending the Great Plains Super Launch  (GPSL) conference being held in Nampa, Idaho.  We will launch a 1200g exempt balloon and a pico balloon.  Our 1200g launch will be part of the mass launch associated with GPSL.  The pico balloon launch will most likely not occur with the mass launch due to the need for an indoor inflation of the balloon.  We're looking at a fill and launch at the end of the tech session on Friday.

With our pico balloon launch we'll be attempting an around-the-world flight. The balloons used will be two 36-inch mylar party balloons tied together and filled to achieve superpressure and float at about 40,000 feet. This should be above most thunderstorms. The balloon will carry a solar-powered WB8ELK Skytracker beacon, weighing 15 grams. The beacon transmits on 20 meters (14.097 MHz) at 20 mW using the Weak Signal Propagation Reporter (WSPR) protocol. The signal will be picked up by amateurs throughout the world monitoring WSPR frequencies and posted to the WSPRnet server. From there, a program running on a local computer will read the WSPR packets, reformat the information and post it on the APRS servers. The balloon can be monitored on WSPRnet as KCØRPS and on APRS.FI or FINDU as KCØRPS-11.

A clever scheme using two WSPR packets is needed to report the necessary information. This includes location (6-character Maidenhead locator) within one mile, altitude within 200 feet, temperature within 5 degrees, GPS satellite status, and the solar panel voltage. All of this information is reported in the APRS packet. The beacon transmits every 10 minutes during daylight hours and goes dead at night.

Pictures of the balloon, beacon, and link to a video are available at: http://gmigliarini.wixsite.com/wb8elk



Payload Plan: 


Event Date: 
Saturday, June 16, 2018 - 00:00
Flight Coordinator: 
Best Western Motel in Nampa as reference point. X=20, Y=20 Grid Test N 43.500 W116.000 result X 48.7 Y 14.3


One 1200g balloon included in the mass launch at GPSL 2018 in Nampa Idaho

Balloon Type: 
Totex 1200g Latex
10 foot Rocketman
Tracking Beacons
144.360 MHzAEØSS-13APRS/Digipeater EOSS 0.350WPrimary Beacon
144.905 MHzKCØD-1APRS/Digi/DF Release #2Secondary Beacon and release

Preflight Net:

  • Eyeball net after tech session on Friday

Recovery Operations: 

  • 146.100 MHz Balloon Field Simplex
  • 444.900 MHz PL 100 Nampa Repeater


Launch Site Simplex: 446.050 MHz

HF - Possible ops: 7.235 LSB

Tactical Calls: 
TacticalCall SignNameNotes
AlphaWA0GEHMarty, Sharon00:02, Tracking Coordinators, Downrange
BravoKC0LJohn00:07, Downrange Trackers
CharlieKC0RPS, N2XGLJim, Jeff00:12, Launch, Trackers
DeltaK0SCC, N0LPStephen, Nick00:17, Launch, Trackers
EchoKD0SEMDave, Dan, Cheryl00:22, Downrange, Trackers
FoxtrotKE7KCKTom, Denise00:27, Downrange, Trackers
GolfN0NDM, KB0YRZ, W0CBHLarry, Chris, Benjie, Rosie00:33, Launch, Tracker
TR Breakfast: 
6:00 Breakfast at McDonald's near Best Western. Trackers deploy to recovery, launch team to launch site..