University of Minnesota
School of Physics & Astronomy

Spotlight

EBEX in Flight

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Asad works on the cryostat, a.k.a "the Champagne Bucket"
Asad Aboobaker
                                                       

Launching a balloon-borne scientific experiment, or "balloon campaign" can be a long, intense operation where physicists work in isolated locations that can make a balloon experiment seem like a military campaign. Asad Aboobaker, a Research Associate at the University of Minnesota, working in Shaul Hanany’s Observation cosmology group, blogged the EBEX launch in Fort Sumner, NM.

Aboobaker chronicled the group’s set-backs, small triumphs and near-disasters as they readied for the launch.

Aboobaker’s job was to lead the integration of the instruments in the cryostat, a large “fridge” full of liquid helium that keeps the instruments cooled so that they can reach the maximum detection sensitivity. He also worked on the mechanics of the balloon gondola. At one point the group believed they were going to need to add a large amount of counterweight to one side of the payload to ensure it could point at different locations on the sky correctly. Because adding the counterweight would have put the payload over its weight allowance, Aboobaker came up with the unique solution of adding heavy-duty springs to one side of the gondola to provide the necessary restoring force. The solution, using common garage door springs, replaced 600 lbs of counterweight.

Aboobaker also worked on the gondola’s baffle, which is a large, light weight shell that protects the detectors from signals from the sun since the experiment is trying to pick up the extremely faint Cosmic Microwave Background radiation. During one of the days that the experiment was moved to the launch pad for outdoor tests, high winds shredded the baffle. “It was a disheartening day,” he said. The group managed to fix the baffles and strengthen the supporting structure in time for the next launch window. Aboobaker says his job often amounts to finding creative ways to solve problems quickly.

EBEX successfully launched, but what was the triumphant end to one campaign was just the beginning of another. The flight was a dry run to optimize and increase the detectors for a launch to take place in Antarctica in December of 2011. The group is doing data analysis so that they can make the necessary adjustments to their design for the Antarctic flight. Aboobaker says the gondola took a fair amount of damage when it landed but most of the instruments on board survived. The group needs fix the balance issue and further reduce weight when the gondola is rebuilt to ensure a successful Antarctic flight. Aboobaker is busy working on the new design and will be in Antarctica for the balloon campaign at the end of 2011 along with his blog. “There is a lot of work to do, but I’m looking forward to it.”

More information at http://groups.physics.umn.edu/cosmology/