We are living in a golden age for astronomy, as cutting-edge observatories probe the earliest moments of the universe, map the cosmos, and study planets orbiting distant stars. The next generation of telescopes will advance that work still further, with capabilities under development enabling studies of small, Earth-like planets, which could result in the detection of signatures of life. However, designing and building these telescopes present tremendous challenges. How do you choose what capabilities a telescope should have, and how do you decide the time is ripe to build it? How do you allocate resources among different telescopes in a portfolio, and how do you maintain policymakers’ confidence as you build them? Our guests have decades of experience confronting such problems, which they are drawing on as they lead the work of carrying future telescopes from drawing board to reality.