Pi-heptomino

A growing spaceship which uses the pi-heptomino.

It does include a pseudo-spaceship based on the Pi-heptomino (pseudo because it needs some classic spaceships in front, and so the middle gets longer and longer.

1) gliders on paths *adjacent* to the six annihilating paths produce a pi-heptomino and consequent large explosion -- and there's no way to place blocks on nearby lanes to catch those gliders, because they'd interact messily with gliders on some of the original six glider paths;