http://apcnasa3ozl2j74htizuzba5b6nhugbg2qze2nrz43siunkct555fpid.onion
Finally, note that for an "ideal" rocket, with zero dry weight, M PL is just M b and there is no advantage to staging. For "real" rockets, with finite dry weights, staging is always advantageous, although a theoretical limit is reached with an infinite number of stages, as shown in the previous figure.