Launch weather for NSTAR 06-A was a solid overcast, but fortunately the winds were relatively light when we arrived at Scott KC0MTH’s place northeast of Treynor. The balloon fill and payload checkout was pretty uneventful and we launched at 0758 CDT (1258 UTC).
Our landing was expected to be a few miles south of Lyman IA, so we headed east on Hwy 92 toward Griswold and stopped at a local gas station for some snacks and to await the balloon burst. We had a few problems with packet reception, but attributed that to being almost directly under the balloon and in the payloads’ antenna nulls. We got enough data from the two payloads to have an idea of what was going on, however. Burst occurred at 0922 CDT (1422 UTC) at 92,290 ft.
As we were departing Griswold, we noticed that the N9XTN-12 altitude was decreasing much too rapidly. It became apparent that once again the backup beacon had fallen off the main payload and was in a free fall. Fortunately due to its light weight it was not particularly dangerous. Doug KA0O volunteered to monitor N9XTN-12’s descent and landing, heading south of Hwy 92 east of Lyman. We were able to capture a packet at 3200’ MSL, which was less than a minute before landing, so we thought we’d have a relatively easy search.
Wayne KE6DZD and I continued east on 92 to Lyman and then south, following the main payload’s track. The payload was transmitting as it should be, but for some reason the packets were a little distorted at times and would not decode. We lost much of the data on descent, and stopped updating below 14,000 ft which made planning the end of our chase more difficult. Finally we did get some packets just before landing, which occurred at 1007 CDT (1507 UTC) in a pasture about 14 miles east of Grant, IA.
After recovering the main payload, we returned to the search area for the backup beacon, which was a couple miles southwest of Lyman. Doug was already on foot searching the field under and downwind of the last report. The field was planted in corn which was between knee and hip high and had not quite grown enough to obscure our view when looking down the rows. The red color of the beacon should have made it stand out. There were a few grassy strips in the field for erosion control, which was chest high in grass and weeds and more difficult to see through. With light winds from the northeast below 3200 ft MSL, we expected the payload to be very near to perhaps 100-200 yards south and west of the last report. We conducted a search of the area for about 90 minutes, expanding as much as 500 yards south and east, plus the entire area within 200 yards of the last report. We also closely “stomped” the grassy areas as well. All was for naught, however, and we headed home shortly after noon. I did not expect I would see this payload again until harvest time in October, if ever.
Later in the week, I received a call from a farmer near Grant. His son had found the backup beacon while cutting hay in the same field we had searched. I was not able to speak with the son to get a better idea of where he found it, but was grateful to get the payload back again. No damage was noted and the electronics all worked when recharged and powered up. We had used a more robust spring clip for the attachment to the main payload, and apparently it worked itself open too. On NSTAR 05-B we also had a spring clip failure, but it was a tiny clip with a weaker closure. It seems the large spring clip had also failed to stay closed. I have always preferred spring clips for ease of assembly at the launch site, but it appears that’s too risky. We also use spring clips at other attachment points for the same reason. Some of them will be replaced with alternate attachment methods, and the rest will be taped shut after attachment.