In order to launch the space remote sensor sucessfully

the modal characteristic of a truss for enduring the dynamic load was calculated by Finite Element Method(FEM)

and the modal test was done by the hammer beat method. The calculated and tested frequency result was compared

and the visual comparing method and the Modal Assurance Criterion( MAC ) were employed in the relativity analysis of the modal shape. Experimental result shows that the first-order order frequency of the truss is 154 Hz

which satisfies the design requirement above 140 Hz

and the calculated error of the FEM is less than 10%. There are some shape relativity less than 0.5 in partly

so the FEM model needs to be modified for the following engineering use.