Read here about tensegrity structures composed of nine struts, part of a series of pages organized by strut count.
A t-prism can be constructed with 9 struts.
Multiples of 3
The tensegrity simplex is the 3 strut construction, often called the tensegrity tetrahedron. Most 9 strut tensegrities are constructed by varying the 3 strut simplex. A mast can be assembled by repeating the 3 strut module 3 times, or each strut of the simplex can be tripled, yielding a 9 strut construction.