December 15, 2008, McMurdo Station, Antarctica -- Tom Gaisser
Long-Duration Ballooning in Antarctica
Yesterday, a group of six IceCubers left the South Pole on the first leg of the trip North. We arrived here about 6 p.m. The original schedule called for our replacements to be on a flight south from Christchurch that same day and we were to meet here in McMurdo. The flight from Christchurch was postponed until today, which gave me an extra day in McMurdo.
I met two colleagues in the galley here who invited me to visit the Long-Duration
Balloon (LDB) facility today. Eun-Suk Seo is a professor at the University
of Maryland who leads the Cosmic-Ray Energetics and Mass (CREAM) project.
I also met David Saltzberg from UCLA who works on the Antarctic Impulsive Transient
Antenna (ANITA).
The goal of CREAM is to make direct measurements of individual cosmic-ray nuclei to the highest possible energy. The ANITA detector is designed to detect neutrinos of ultra-high energy by recording the radio waves produced when they interact in the ice. Both detectors benefit from flights of long duration at high altitude. The CREAM experiment can detect primary cosmic-ray nuclei before they interact in the atmosphere. The high altitude gives ANITA a view over thousands of square kilometers of ice to look for neutrinos.
Above, Eun-Suk Seo from the University of Maryland and Tom Gaisser from the University of Delaware in front of the CREAM payload. Below, the ANITA detector assembled for launch with Tom shown for scale. Photo by David Saltzberg.
This is the NASA balloon launch vehicle that carries the payload as the helium-filled balloon rises. In the background are the high-bay buildings in which ANITA (in the back) and CREAM are being prepared for launch.
Although the scientific goals and techniques of these two experiments are rather different, they make use of the same NASA Long-Duration Balloon facility (see http://www.nasa.gov/vision/universe/starsgalaxies/cream.html). During the Austral summer, a polar vortex is established in the upper atmosphere. The circulating winds then allow balloons to make several circumnavigations of the Antarctic continent. The record (41 days) is held by the first CREAM flight. The current flight of CREAM may go as early as tomorrow. ANITA will follow later.
I took this picture (above) of the Pathfinder balloon as it was being filled with helium just before launch this morning. It will probe the upper atmosphere to check wind patterns to determine whether CREAM can be launched tomorrow. The flight from Christchurch is due here in an hour or two, and we are scheduled to fly out early tomorrow on the same plane (a South African C130). We have “bag drag” at 20:00 tonight and our transportation to the airfield is set for 03:30 tomorrow. The view of Mt. Erebus (about 25 miles away) is what we will see when we board the plane if the weather is still good.
View of Mt. Erebus from the LDB facility. The Williams airfield is nearby.
