This has been a hard week for lovers and dreamers of space travel — a frequent topic at TED. An explosion at Burt Rutan’s Scaled Composites spaceport caused three victims. It was followed by a report on issues of personal safety at NASA, part of the unfolding story there.

Space exploration is an inherent high-risk endeavor. We invite you to view several talks on TED.com that can help recapture the excitement and pure imagination that has inspired generations of people to reach for the stars: Burt Rutan’s own vision, Bill Stone’s audacity, and cosmologist David Deutsch, who tells us that humanity’s true purpose — the reason we exist — is to explore and learn, to gain knowledge.