  We study the mass scales in the $SO(10)$ grand unified theory based on the
following minimal Higgs representation content: adjoint $45_{\rm H}$, spinor
$16_{\rm H}$ and complex vector $10_{\rm H}$, with higher dimensional operators
on top of renormalizable interactions. We show that the consistency of the
theory requires scalar $W$ and $Z$, scalar quark doublet and scalar gluon to
lie below $ 10\, \rm TeV$ energy and potentially accessible even at the LHC.
These signatures are intimately connected with the prediction of proton
lifetime below $10^{35} {\rm yr}$, to be probed in the new generation of proton
decay experiments.
