EOSS Flight Archives

EOSS-394/395 Gateway to Space & NDIA - Recap

The Saturday flight was delayed one day because of high ground winds and an extended predicted flight path. On Sunday, April 12, 2026, one 1500g balloon carrying student experiments sponsored by the Rocky Mountain Chapter of the National Defense Industrial Association and one 3000g balloon carrying student payloads from CU-Boulder's Gateway to Space program were flown. Both balloons landed approximately 19 miles NNE of Anton, Colorado. The flights were as follows:

EOSS-392/393 COSGC Spring Flight - Recap

EOSS 392, 393 Heavies Rev B has new tops and bottoms. EOSS 392. 392, 394 Lites Rev A overweight waiting for final weights on April  1. We may have to drop some payloads.  This will be two 3000g balloons or three 1500g balloons carrying student payloads for the Colorado Space Grant Consortium program.   If clouds prevent the launch of 3000g balloons, the payloads will be separated and launched as 3, 1500g payloads.

Flight prediction: https://eoss.org/predict.

EOSS-391 - Qualification Flight - Recap

One 2,000g balloon was launched on March 21, 2026 from Deer Trail Colorado with EOSS qualifying payloads and a new ADS-B built by Metro State University - Denver.  The balloon was launched at 8:00am with the help of members from the Parker Radio Club. The balloon reached an altitude of 91,900 ft when it burst.  Trackers were talking to the landowner (just north/east of Arabia) as the parachute and payloads landed about 50 ft from the driveway they were standing in.  One of the easiest recoveries!

EOSS-388/389/390 Ranum Innovation, Golden HS, and Evergreen HS - Recap

Three 1500g Lite balloons were launched from Deer Trail on Saturday, December 6, 2025. The upper level winds were higher than expected and the real-time landing predictions were putting the balloons across the state line in Kansas. Ultimately the balloons did land in Colorado and were easily retrieved once landowner permission was obtained. The balloons performed as follows:

EOSS-386/387 COSGC Fall Flight - Recap

Two 3,000g balloons were successfully launched on November 8, 2025, a breezy Saturday morning from Wiggins High School.  The first balloon 386 launched at 6:47am reaching an altitude of over 100,000ft. The second balloon burst upon filling, and a backup balloon was successfully filled with 387 being launched after 7 am reaching an altitude of over 80,000'.

EOSS-384/385 Metro State University - Intro2Space - Recap

On Sunday, November 2, 2025, two 3000g balloons were launched from Wiggins High School, carrying fourteen Metro State University Intro2Space payloads. Because of an excessive long prediction for Saturday, the flight was delayed until Sunday. The weather was cool but managable. The balloons flew as follows:

EOSSP-3/4 Pico Balloon Launch at HAMCON 2025 - Recap

Monitor all three EOSS pico balloons here.

EOSS-383 NDIA Flight - Recap

(Draft of flight summary)

EOSS-383 was launched at 7:25 a.m.on Saturday, October 17, 2025 from the Limon Softball Complex and achieved an altitude of 96,548 feet before cutdown and release of the parachute which brought the payload safely to rest at 09:48 AM in far eastern Cheyenne County near the intersection of CO State Hwy 385 and  County Road Y (38.9233333,-102.3451667).

EOSSP-2 Pico Balloon Launch - Recap

This isn't really a Recap, because the pico balloon is still flying, as of March 9, 2026 (day 172) it has made thirteen circumnavigations of the world (see map in Charts & Data).

EOSS-381 &382 Colorado Space Grant Consortium Summer Launch - Recap

This will henceforth be known as the EOSS 381/382 Fog, Battery, Brakes, Fork Flights. Two 1500g balloons were launched from the Limon Soft Ball Fields on Saturday, August 2, 2025.

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