For further information email dsmith (David Smith) at scipp.ucsc.edu.
Payload J1: Launched at 2115UT on January 20th, and currently at float. The x-ray detector seems to work well at night and is noisy during local day, causing other problems on the payload as well. This may be due to temperature or pressure variations Latest position: -71.31, -51.34E (i.e. west of Greenwich). Note: the latitude of -79 shown earlier was a type for -70; our apologies.
Payload J2: Launched and returned to Earth. Launched at 1400 UT on 17 Jan 2005. After reaching float at 34km a bit less than 2 hours later, it began coming down slowly, and hit ground (or water) about 14 hours after launch. Here is the flight profile for the beginning of the flight, and a closeup on the point where it reached its ceiling. While at float, it saw very high count rates which we believe are due to solar protons from the X-class solar flare at about 0900 UT; we saw many spectral lines from nuclear de-excitation of nitrogen and oxygen.
Payload J3: Launched at 0950 UT on January 24. Currently at -75.387 Lat., -20.373 E Longit.. Data collection is sporadic due to problems connecting with the flight modem.
Payload J4: was LAUNCHED at approximately 1309 UT on January 19. It reached float at 33.2km at 1510 UT. Starting at 25km the gamma-ray detector started registering extremely high count rates (on the order of 20,000 counts per second). The spectrum was consistent with extremely intense electron precipitation. The count rate then came down to about 1,000 counts per second, After 19 hours at float, altitude is within 1km of the initial float. At about 0700 UT we were hit by an enormous flux of solar protons from a well-connected X7 flare. The detector was so overwhelmed that it may have sustained some temporary damage, but seems to have recovered and is now working well. Here is the initial altitude profile. Currently at -69.617 Lat., -72.84 E Longit. Data collection is sporadic due to problems connecting with the flight modem.
North and South have now launched all payloads.
Wednesday, Dec 17, 2003
After bouncing up and around Mt. Discovery, the MINIS payload broke free and rose up again to about 3 km, moving southwest. A helicopter reconnaisance flight confirmed that it was aloft again, and that it had lost its booms. It made it over the Royal Society Range and out to the plateau, continuing to rise to 9 km, the height of the tropopause. After that, it turned westward and very gradually came down. The last position it reported was 77.6869 S, 127.8722 E, 3332 meters altitude, at 05:58 UT on December 17. This is only a few hundred meters above the altitude of the plateau at that position -- we conclude that it probably came down shortly afterwards and we lost telemetry (which had already been spotty since the original landing(s?)) once it hit the ice. The distance, the probable degree of damage, and the lack of remaining battery life make a recovery unlikely.
Our best guess as to what happened is that there was a hole in the balloon about halfway down. When it reached 14km (well above the tropopause), the helium bubble was big enough to see the hole, and it leaked a lot of helium quickly, bringing it down to the ground. On landing, it bounced and dragged up the mountain losing its booms, so that with less weight it had some positive lift -- enough to bring it up to the tropopause but not enough to cross it, and therefore not enough to trigger further leakage -- thus the second descent was several times slower than the first.
Monday, Dec 15
Launch occurred at 09:40 UT and went fairly smoothly, with all systems active, however upon reaching 13.8 km the payload came back down, probably due to a leak in the balloon (since it passed the tropopause without slowing badly, there was initially plenty of lift). The payload came down on the lower South flank of Mt. Discovery, and as of this writing is still bouncing and/or dragging slowly along. Most systems (including the scintillator, flight computer, and Iridium uplink) are still functioning. A helicopter recovery is being considered for tonight.
Sunday, Dec 14, 00:00
Testing of the payload continues at Williams Field, after successfully moving from McMurdo Station two days ago. Launch is possible within 24 hours.
The 2003/4 McMurdo campaign was funded by the National Science Foundation (NSF) Atmospheric Sciences section. The 2004/5 SANAE campaign was funded by the NSF Office of Polar Programs.