In the framework of the Sen conjectures a construction of vacuum superstring
field theory on a non-BPS brane is discussed. A distinguished feature of this
theory is a presence of a ghost kinetic operator mixing GSO+/- sectors. A
candidate for such kinetic operator with zero cohomology is discussed.Comment: expression for the pure ghost kinetic operator corrected, Comments
added; 21 pages, 1 figure, LaTeX 2