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Neutrinos on Ice: Waiting to Fly

It’s another beautiful day in Antarctica, and the time has come to launch ANITA! Finding the right date is tricky. Many factors have to fall into place.

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


It's another beautiful day in Antarctica, and the time has come to launch ANITA! Finding the right date is tricky. Many factors have to fall into place. In order to detect neutrinos and cosmic rays, we want to fly over the Eastern ice sheet in Antarctica. We detect these particles via their radio emission. The smooth ice provides a great surface for the radio waves to refract in a predictable way, as opposed to the mountain ranges in central Antarctica and the bumpy coastline.

A polar vortex, forming a giant ring of stratospheric winds, sets up around the South Pole in early December. The air currents in the vortex dictate our flight path. If we launch too early, and the vortex hasn't set up properly, we might end up flying over the ocean, which we don't want. We want to get as much flight time as possible, to maximize the exposure time we have for detection.

Each day we check the vortex maps and forecasts that NASA prepares.


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Once the vortex is up and going, we wait for the weather conditions to be right. The winds have to be low, under 10 knots, and heading in the correct direction. Launching a balloon takes up to 10 hours, so the weather has to be good for a long time. Conditions change rapidly in Antarctica. If we think 10:00 a.m. might be a good launch time the next day, we wake up and prepare at 2:00 a.m. that morning. We launch pibals to gauge the wind conditions.

Six years in the making, the success of ANITA is dependent on the next few days. All the antennas are connected for the last time. Once NASA declares us “flight ready,” we don't touch the experiment, so there is no way to be positive that we have everything hooked up correctly. This leads to checking, double-checking and triple-checking. The last bits of they payload are painted white to ensure they don't get too hot during the flight.

Now we wait for the weather to cooperate. So far we have had five attempted launches. Riggers from NASA's Columbia Scientific Balloon Facility bring ANITA to the launch pad (called “rolling out”) and prepare to unroll the balloon. There is no going back once the balloon is taken out of it's box, so that point is often when the CSBF weatherman makes the crucial decision about whether or not to launch.

We were very close to launching on December 14, but high winds picked up at the last minute. We even had a special visitor come to watch the potential launch. A few hours before flight, an emperor penguin wandered out to our facility! It is still a little early to see penguins here, so it was a great surprise.

While waiting for launch, we had the opportunity to check out the site of the Pegusus airplane crash that occurred in 1970. As the C-121 Constellation (named Pegasus) neared Antarctica, a severe storm picked up. The plane didn't have enough fuel to return north, so it attempted to land blindly on the ice runway. It was a serious crash, but, amazingly, there were no fatalities and only five people suffered minor injuries. The wreckage is preserved in the snow near the airfield, now named Pegasus Field. It's a very cool historical landmark.

Katie Mulrey received a B.S. in Physics and Mathematics at the University of Mary Washington in 2008. She is now in the final phase of her Ph.D. work in High Energy Particle Astrophysics at the University of Delaware. Katie is a part of the ANITA collaboration and is heading to Antarctica to participate in the 2014 ANITA balloon campaign, which will probe the highest energy processes in the universe.

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