The Far Future of Intelligent Life Across the Universe - Stuart Armstrong. On how a technologically mature civilization may be able to explore the universe.
Visions, Ventures, Escape Velocities: A Collection of Space Futures - Ed Finn, Joey Eschrich. Dropbox link to a comprehensive book covering practical and philosophical matters of space exploration.
Life As It Could Be: Astrobiology, Synthetic Biology, and the Future of Life - Library of Congress. Longish recording of the future of life in space.
Space Governance - 80.000. Intro post with risks, near-term opportunities, and organizations.
Space Races: Settling the Universe Fast - Anders Sandberg. Examines the issue of the resource demands and constraints for very fast large-scale settlement.
Cosmos - Carl Sagan. Also Pale Blue Dot. An early inspirational account of our potential future in space, including early space images.
What’s It Like in Space? - Ariel Waldman. An illustrative account of the constraints and possibilities for human life in space.
How Space Exploration Replaced Religion in the USSR - Sasha Rospopina. On what it looked like to put space exploration first for the USSR.
You Are Not Where You Think You Are, What Do Alien Civilizations Look Like? - Kurzgesagt. Explainer video on our place in the universe.
The 12 Greatest Challenges for Space Exploration - Wired. Intro-level post on technical challenges we have to overcome for space exploration.
The Edges of Our Universe - Toby Ord. Divides the universe into, affectable, observable, eventually observable, and ultimately observable universe.
Space is for Everyone - Rachel Lindberg. TED talk arguing for a democratic approach to space exploration.
Space Law and Policy - Ali Prince. Discusses international cooperation and competition around space policy issues.
Aerospace Knowledge Guide - Website. Introduces useful terminology on space.