Why not just use the DPFs to propel a very larger ship with water tank shielding and enough space for artificial gravity?
Lets be realistic here: a DPF is not a vonder engine, sure its has a ISP between 100,000-2,000,000sec but its does not have much thrust, this makes it great for speeding from planet to planet but a DPF could not “take off” from anything larger then an asteroid. So DPF does not answer the hardest problem there is in space travel: getting off the earth. Unless of course you use some DPF powered laser/maser array to
