NSTAR 07-A should have been labeled our "return to flight" mission, as it had been 391 days since our previous flight. That beat our previous interval by almost a factor of two.
In the day or two prior to our launch date, it became apparent that (a) surface winds of 10-15 mph from the southwest would be present at launch time, and (b) we would need a launch site south of I-80 in order to avoid the possibility of landing too close to the Platte River or I-80 itself. Fortunately Roger found an excellent launch site for us - a trap shooting range on the north side of Doniphan, NE which also happened to have a great windbreak for the expected southwesterly winds. We moved the planned launch time earlier to 0700 CDT to get into the lightest surface winds possible.
Saturday the 7th dawned clear and a little breezy, as expected. We were a little behind schedule and didn't arrive at the launch site until 0620. Some groups were already filling balloons as we found our parking place. We could see that the treetops were waving in the breeze but the trees did an excellent job of sheltering us from the wind. We got unloaded and were ready to fill our balloon by about 0645.
I had debated whether to use a 1200g balloon or a 2000g balloon. I had four 1200g balloons on hand that were purchased from eBay at about $40 each. The 2000g balloon was bought for almost $200 when Kaysam went out of business and I had had it for about two years. Because the winds were expected to increase, I opted to fill one of the cheaper balloons.
The fill process went normally and we were ready to hook up our payloads. We had recently gone away from using the "lanyard" method of getting the balloon up because of their tendency to twist and become fouled. Instead, we slip the load line between the balloon and the parachute carefully through gloved hands, then up the parachute and spreader ring until we have hold of the main payload. The backup payload, separated by 20' of line, is then placed downwind and is simply jerked off the ground at launch.
Rather than using gloved hands, I decided to try using a spring clip as a pulley. The balloon would be let go and one person would hold the parachute and allow the load line to slip through the metal clip rather than through gloved hands. This would avoid the possibility of rope burns. We started this process and had begun to raise the balloon when the knot broke at the top of the chute. This released the balloon with nothing but 15' of string attached.
An expensive loss, but not fatal to our ability to fly that day. I then decided to go for broke and use the 2000g balloon and one of the spare helium tanks CNNSP had made available. We had never lost two balloons in one day, so what were the odds? The winds were staying quiet enough, so we started filling the 2000g balloon. We soon noticed a roach or other large insect had apparently taken residence in our fill tube and was blown into the balloon's interior.
Harry KC5TRB approached us around this time. The NSTAR main payload was slotted to transmit between :20 and :30 seconds past each minute. However, some of the transmissions were occurring at about :32 past. I was unable to reprogram the time slotting code and Harry was already airborne. Fortunately the :20-:40 time slot on 144.36 was still open and we just changed to that frequency to avoid the interference.
The balloon fill proceeded normally. We made our last-minute payload checks again and launched at 07:19:04 CDT.
The early part of the flight proceeded normally as we watched the balloon head east-northeast for a few miles before turning around and passing to our south. Paul KD4STH had launched about 40 minutes earlier and was looking for someone to convoy with for the chase since he did not have any tracking equipment. Because of the disparity in launch times and the fact our payloads were on the same frequency, we offered to help him chase, then we'd have plenty of time to get in position for our chase.
We headed south from Doniphan to Hastings, then east from there on US 6 towards Heartwell. From the previous day's predictions and the way the flights were tracking, we estimated Paul's payload would land a few miles east of Heartwell and not far from US 6. We stopped on US 6 for a few minutes, then headed south on a county road and were able to spot his parachute. It passed directly overhead and we were able to see it land in a soybean field about four miles ESE of Heartwell.
After we recovered Paul's payload, ours was crossing over 100,000 ft. We had hoped our 2000g balloon would best NSTAR's previous record of just over 105,000 ft, and perhaps be the highest for the day. We knew Near Space Ventures had reached just over 109,000 ft earlier. We got a report of 108,055 ft, then nothing for a period of time before burst. We were able to see the balloon as it burst - it was like a bright star that faded out over a couple of seconds. Later, our on-board logging showed a maximum altitude of 110,915 ft at 09:03:32 CDT.
We began heading southwest towards Minden. We had hoped to find a gas station but there weren't any that appeared to be open. We went north on Hwy 10 out of town and stopped to see how the end of the flight would evolve. The payloads began turning almost due east along a county road below 15,000 ft, so we began heading north a little farther.
At around 8000 ft, I could see two separate objects in the sky at the right location. At first I thought we were seeing someone else's payload that just happened to be descending along with ours. Within a few seconds, it was apparent this second object was falling much faster than the first. I rechecked our telemetry and both APRS payloads were still attached. The second object was the remains of the 2000g balloon which had finally torn loose from the neck ring and fell separately. This lump of latex fell in a cornfield off to our right as we were heading north.
We turned east off Hwy 10 onto a county road. The payloads were also traveling due east and we stayed under them for the mile and a half as they drifted east about 15 mph. They fell into a farmhouse's back yard at 09:39:10 CDT, narrowly missing the house and some power lines.
As we walked up, we could see the owner coming back towards the house. She had seen the payloads on the ground and was heading towards them. We identified ourselves and explained what we were doing. She continued her chores outside while we were getting photos and checking things over. I got her address and said we'd send some photos and other information once we compiled everything.
