Satellite Structural Design - Finite Element Analysis for Satellite Structures - page 75

Fig. 3.32 Basis plate

Fig. 3.33 Basis frame

Rivets

Mounting seats and precise holes are provided on the outer surface of the frame to
install the ADCS devices. The basis frame provides mounting seats for two reaction
wheels in the Y, and X-directions, both X and Y-direction gyros, and three interface
units of X, Y, and Z-direction gyros. One of the frame walls contains two seats for
mounting PCU and CLU. The mass of the basis frame is 4.88 kg.
The basis plate and basis frame are fastened together using four M8 screws and
reinforced by two diagonal struts as shown in Fig. 3.31 . Each of the two diagonal
struts is connected to the basis plate and frame using two M6 screws. The diagonal
struts are channel bars made of aluminum alloy AMg6. The mass of each strut is
0.08 kg. 86 mm diameter holes in the basis plate and frame are provided for
installation of the eight studs connecting the satellite case subassembly. A bracket
for installation of the inclined star sensor on the basis unit plate is a welded
structure made of aluminum alloy AMg6. The star sensor bracket is installed on
the basis plate using four M8 bolts. The total mass of the basis unit case without
the star sensor bracket is 7.7 kg.

3.5.4 Upper Frame

The upper frame consists of four milled walls connected together by rivets as
shown in Fig. 3.34 . The upper frame walls are made of aluminum alloy AMg6.