Gondola:

BLAST consists of a precision-pointed inner frame (composed of the primary mirror, secondary mirror, near-field baffle, and cryostat) supported by an external gondola. The outer frame will be pointed in azimuth by a flywheel and an active pivot. The inner frame has an elevation mount and is driven by motors relative to the outer frame. Balance of the inner frame will be achieved using actively positioned weights for differential buoyancy and cryogen blow-off.

The cable-suspended gondola design is lightweight, with a high tensile strength and a high resonant frequency. The gondola has a 8 m hook height and 4.4 x 2.9 m² footprint. A PDF diagram of the gondola is available here.