Spacecraft Structure - Model

MidSTAR's frame is an octagonal structure 32.5" along the long axis, including separation system, and 21.2"x21.2" measured side-to-side in cross-section. The deployment mechanism is mounted on the negative x face. The positive x face is reserved for externally mounted experiments. Of the 38" along the x-axis allowed in the ESPA envelope, 2-4" are reserved for the deployment mechanism; 4-6" is reserved for external experiments, and the frame length is 30". All eight sides of the spacecraft are covered with solar cells in order to maximize the power available. Eight dipole antennas are mounted on the four faces of the spacecraft which "cut the corners" of the ESPA envelope, and are therefore positioned within the ESPA envelope rather than coincident with the envelope surface. The remaining sides will be mounted with remove-before-flight eyeholes for lifting and transport during ground support. All eight sides of the spacecraft are covered with solar cells in order to maximize the power available.

MidSTAR features three interior shelves, which provide area inside the satellite for mounting of components and payloads. Their locations are determined by the dimensions of the payloads and components. These can be varied if necessary, as long as the structure remains within the center-of-gravity requirements.

The load-bearing structure of the octagon consists of the top and bottom decks, connected at the eight corners by stringers. The side panels of the spacecraft are 1/8" aluminum panels mounted to the stringers with #10 bolts. Three of these plates will be rigidly attached to the stringers using a nut and bolt combination. The remaining five panels will be removable to allow for access to internal components and payloads.