groovesoop posted a photo:

The “Boss” launchpad vehicle hoists BESS at its assembly area outside the “Pig barn” at the Long
Duration Balloon facility, Dec. 13, 2004, near Williams Field, McMurdo Station, Antarctica. At nearly 45,000kg, the Boss is built with a low center
of gravity and enough power to accelerate the payload into position and get out of the way
when the balloon launches.