Surviving Interstellar Travel

Even at faster than light speeds, interstellar journeys are long and James Blish's characters have different ways of surviving them. In Cities In Flight, entire cities fly through space and the citizens have the anti-agathics so it is possible to live and work in a city for years or decades yet not succumb to old age before journey's end.

The cities also use plants called Chlorella, which are explained in more detail in Mission To The Heart Stars: they renew oxygen, remove carbon dioxide and can be eaten.

In Mission..., the liner adapted to take three men to the galactic centre is powered by a Nernst generator which uses interstellar hydrogen for fuel whereas the flying cities need to mine or buy power metals and one city rightly regards it as important when they claim to have the fuelless drive.

Finally, the ship in Mission..., like other spacecraft mentioned in the same novel, recycles all water, even from human waste. Water recycling, Chlorella, the Nernst generator, large storage areas and stops for supplies enable the crew to make and survive their three year journey to the galactic centre.

An Angel accelerates their return.