Superspace Action for the First Massive States of the Superstring
  Using the manifestly spacetime-supersymmetric version of open superstring field theory, we construct the free action for the first massive states of the open superstring compactified to four dimensions. This action is in N=1 D=4 superspace and describes a massive spin-2 multiplet coupled to two massive scalar multiplets. 
N. Berkovits and M.M. Leite (IFT/UNESP, Sao Paulo)