In 1971, the lab’s scientists and engineers faced a variety of challenges and setbacks while building the Main Ring and the rest of the lab’s accelerator systems. One of the problems they encountered was construction debris in the vacuum tubes that would be used in the Main Ring. This debris interfered with the movement of particles through the tubes. At the suggestion of lab employee Bob Sheldon, the lab obtained a ferret named Felicia to assist with cleaning vacuum tubes in the Meson Laboratory, which is in the lab’s Fixed Target Areas north of the Main Ring. Lab staff, including Walter Pelczarski and Don Richied, fitted Felicia with a harness attached to a string, then encouraged her to run through tube segments. Once she had pulled the string through the tube, lab staff could attach a cleaning swab to the end of the string and pull it through, clearing out any obstructions in the tube.
Felicia caught the imaginations of many people inside and outside the lab. The lab newsletter ran an article about her on September 2, 1971, and soon afterwards the Chicago Tribune, Chicago Sun-Times, Aurora Beacon-News, Minneapolis Star, and Time Magazine all published articles about her.
Felicia was able to assist lab staff with clearing some segments of vacuum tube, but ultimately the lab needed to clean tubes that were too long for Felicia—she was unable to travel through more than about 300 feet of tube, and many of the segments that needed to be cleaned were considerably longer. In late 1971, lab engineer Hans Kautzky developed a robotic mechanical spear that could pull a magnetic cord through these long vacuum tubes. The lab retired Felicia, and she spent the rest of her life in the homes of lab staff who had worked with her. She became ill in May of 1972, and she died in a veterinarian’s office on May 9, 1972.