ESOS Flight updates

Welcome the ES-OS (Experimental Sub-orbital Society) Flight page update

ES-OS6 Launched an incredible 126k cubic foot balloon as part of the GPSL (Great Plains Super Launch) that took place June 14th, 2003. "ES-OS" was one of six amateur balloon groups that launched balloons in support of the Colorado Spacegrant college balloonsat workshop.. The flights launched from Deer Trail, Colorado, about 70 miles east of Denver. ES-OS6, according to APRS data reached an altitude of 106299 feet above sea level.

Filling the 126000 cubic foot mylar envelope

Standing by for Launch

ES-OS6 Envelope Release

Envelope lifts off, almost at payload train release, more than half the balloon is on the ground

Payload train
release and ground crew

Note other balloons in background being prepped for launch

Payload train on its way to 106,299 feet in a blue Colorado sky!

A full-up ES-OS6 mission begins, just seconds after liftoff

The Recovery Crew approaching the landing site, west of Deer Trail, and avoiding the "man eating" "tatonka", Lakota Souix for "buffalo"

Click here for the previous ES-OS5b mission page

Click here to join the ES-OS email reflector and email KC0JHQ for flight updates and more information.

You are visitor number

Photography courtesy of Jim Langsted



	"ES-OS SIX" flight campaign notes. Flight June 14, 2003 K. Mark Caviezel, KC�JHQ Two weeks prior to the Great Plains Super Launch (GPSL) I cleared out a conflicting engagement and set my sights on building and flying a bigger plastic balloon at the event. With help from James Kilgore, I performed some long overdue modifications on my balloon making tools. The balloon for the "SIX" flight was to be 126,000 cubic feet, quite a bit bigger than we've made before, but the newly worked-over tools made it a tractable task. We only started making the balloon on the Thursday a week prior to the flight. We had no problems in fabricating the balloon, the new tools made it comparable to our last balloon (28,000 cubic feet). Indeed, the modified 'pinch roller' made the finished 126k cu ft bag smaller and more manageable 28k cu ft bag that was flown on the "FOUR" mission. There was a significant amount of 'touch labor' involved in making the 126k bag, but it was about as expected. Since there is no margin for blemishes, it is a tedious process though. But, we persevered and had the balloon built by June 12. Our payloads were performing ok as well. With input from the FAA, the main launch was pushed to 7 am, a 2 hr departure from the previously planned 9 am launch. Although I don't like to aid seemingly arbitrary dictates from the FAA, an earlier launch may be beneficial to my large balloon. Up early and out to the Deer Trail, CO, launch site, we were greeted by absolutely fabulous conditions, near zero wind, pleasant temperatures, and lush green grass. We arrived at 5:45 am, and the helium truck arrived shortly thereafter. Although I had scheduled a 6:30 am launch, I was not in a hurry. Indeed, two students who had a payload to fly did not show up until 6:12, and had to turn on and check out their elaborate "Chemsat" payload. No problem. We integrated all the payloads on to the flight string, had a launch ops briefing and started helium fill at 6:36 am. The flight was planned for three full T bottles, but one bottle was appreciably less than full when we got it. So, we had to 'borrow' some helium from the Arizona balloon group. Unfortunately, we took more than we planned to, and they were a little short of helium later on. Regardless, I shouted a traditional three count countdown and Larry Nobel released the 'bubble' on my count of "Zero!" at 6:52 am. Larry had been heaving down on more than 60 lbs bouyancy before release. The balloon was 200' long and serpentine-staged in the box. With optimal conditions, we opted to go for a 'box launch' and the payload handlers did not have to move more than ten feet to release their payloads. It took 18 seconds from the release of the balloon bubble to lift off of the payload. The balloon was BIG and although I should have known what to expect, even I was shocked by the size of the thing. It made a placid ascent into the beautiful blue Colorado sky. It took me several minutes to confirm that we had a nominal flight going on, the balloon was so big and the winds were so light that many times it looked like the balloon was not going anywhere. Meanwhile, the other balloon groups (all with 1200 gram latex balloons) were filling and pulled off a near simultaneous launch at 7:12 am. The big 126k cubic foot balloon was an easy visual marker to see the other smaller balloons. The predicted flight path was not far, so we weren't in a hurry to take off for the chase. Two college students joined James and I in our chase vehicle. We rendezvoused with other balloon trackers several miles from Deer Trail, just sat and watched the balloons and kept an eye on the telemetry. The 126k cubic foot balloon vent failed to properly open and the balloon reached full inflation and burst at 106k feet. This was a bummer as it's engineered float altitude was 118-119k feet. So, the balloon dumped most, but not all of its helium and started a bouyancy dominated descent, averaging about 450 feet per minute descent. This made for a longer than planned flight, touchdown was about noon. Well, it touched down in a field with yucca plants, and the flight string managed to get severed while on the ground. So, the balloon skin took off, at near neutral bouyancy. For the next three hours, it hovered between ground level and possibly 3000 feet AGL. Eventually, it tipped over, dumped all of it's helium and landed in a green field about 15 miles away from the first landing site. We got permission from the land owner to retrieve the big balloon skin. It filled most of Dick's 3/4 ton pick up truck. Dick hauled the helium, and it was convenient to throw a couple helium bottles on top of the balloon skin to weight it down. We rendezvoused for a late lunch with the other balloon trackers and disposed of the balloon skin in the restaurant dumpster. It was a landmark flight in terms of balloon size, marred only by the failure of the vent to properly open. The next balloon will incorporate a design modification to avoid this type of problem. All in all, it was a long day, but a fun event for all involved.