Wednesday, January 23, 2013

Day 92, January 24, 2012 -- The EBEX has landed.

The EBEX flight was terminated at approximately 11:30AM GMT on January 23rd, or roughly 12:30AM on January 24th local McMurdo (NZ) time. I actually found out about this rather on accident, as I had been watching the payload track on the CSBF website and noticed the altitude, which had been at about 110,000 feet not 10 minutes before, was at 86,000 feet! I checked my email and sure enough I had a message saying the flight had been terminated -- finally!

Termination of a balloon payload involves a few different actions. One is opening the helium valves at the top of the balloon. Another is firing the Universal Terminate Package (UTP), which has a pair of explosive cable cutters that release a collar that holds the bottom of the balloon to the top of the parachute. As the parachute and payload fall away from the balloon, they pull a rip line that tears open the balloon to release all of the helium quickly into space.

And after that, after about 45-50 minutes, the payload lands on the Antarctic plateau! Once on the ground, another UTP separates the payload from the balloon in order to prevent the parachute from filling with wind (very prevalent on the plateau) and dragging the payload (as has happened in the past, most notably during the BLAST 2006 flight where the payload was dragged 150 miles and ended up in a crevasse). EBEX landed here:

This turns out to be not a bad place to land. The coordinates are Latitude: 72°22.63 S, Longitude: 159°2.69 E, at an elevation of about 7350 feet on the Antarctic plateau. Relative to McMurdo, it's about about 400 miles away over the Transantarctic mountain range, but it is only 190 miles from an Italian Antarctic station, Mario Zucchelli Base, at Terra Nova Bay. Hopefully we will be able to stage our recovery out of Zucchelli, which should allow for quicker flight turnarounds and more of the payload recovered.

In other news, the BLAST recovery team (Elio) was finally able to make it out to their payload a couple days ago. Elio posted this picture of BLAST on the ice: . Bad weather at the BLAST landing site has prevented more flights out.

Unfortunately, all recovery operations are on hold at the moment, as we have received word that one of the de Havilland Twin Otter planes (operated by Kenn Borek Air out of Canada) has gone missing in the Transantarctics while en route from South Pole Station to Zucchelli. Naturally, search and rescue operations have the highest priority.

No pictures today.

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