Rocket dry mass
= Rocket dry mass
{title2=$M_{\mathrm{dry}}$}
In this ideal <rocket equation> model, <rocket dry mass> is the <mass> remaining after all usable <rocket propellant> has been expelled: structure, engines and payload. It is the final <mass> in the worked example; if <rocket propellant> remains at shutdown, the final <mass> is larger than the <rocket dry mass>.