How To Find A Colonizable Planet In A New Galaxy

Poul Anderson, Tau Zero, CHAPTER 14.

Finding the 1%:

rule out red dwarfs, blue giants etc;

observe many Sol-type stars simultaneously;

utilizing time dilation, observe them over a long cosmic period;

maybe find ways to use relativity effects to gain information;

identify stars with planets with terrestroid masses and orbits;

cruise close by promising systems;

aided by automation and electronics, use spectroscopy, thermoscopy, photography and magnetography to scan for biological, thermodynamic, chlorophyllic and polarization conditions on planetary surfaces;

return to the system with the most suitable planet;

before then, while en route to the new galaxy, employ the entire crew to devise the necessary instrumentation.

Thus:

a chemist and a molecular biologist design a device to detect and analyze life at a distance;

physicists, electronicians etc build and test the device;

meanwhile, an astronomer leads a group to make tools for remote planetography;

the program employs every assistant, draftsman and manual worker, thus saving the crew's sanity.