The Limits of the Human Body in Space: An Illustrated Guide

Alexis Madrigal, senior editor, The Atlantic: Perhaps nothing has reminded humans more of our fundamental organismness than traveling to outer space. All of the things our bodies take for granted on Earth -- gravity, oxygen, a relatively narrow range of temperatures [...]

The Blue Marble Shot: Our First Complete Photograph of Earth

Al Reinert, screenwriter, Apollo 13: It was the first photograph taken of the whole Earth and the only one snapped by a human. You can't see the Earth as a globe unless you get at least twenty thousand miles away, and only 24 humans ever went that far into outer space [...]

Sparking the Cosmic Imagination

Rita J. King & Zea Barker: On April 12, 1961, President Kennedy woke up to learn that the Soviet Union had launched the first cosmonaut Yuri Gagarin into space. First Sputnik, now this! Immediately, Kennedy met with Lyndon B. Johnson. The speech he gave challenged Congress [...]

The Exploration of Mars by Humans: Why Mars? Why Humans?

Joel S. Levine, senior research scientist, NASA's Langley Research Center: The trip will take about nine months each way with a stay time on the surface of Mars of several hundred days. The length will provide an excellent opportunity to engage the public in the mission [...]

One of the Bravest and Most Selfless Acts in Modern History

Kenneth Reightler, former NASA astronaut: April 12 is a very special day, worthy of celebrating every year. But this year is different. In 1961, as a ten-year-old kid reading science fiction, I could easily believe that people were trying to do what others only dreamed and wrote about [...]

A Triumph of Math, Science, Technology and Engineering

Paul Knappenberger, president, Adler Planetarium & Astronomy Museum: The 1961 launch of Yuri Gagarin into orbit around the Earth -- the birth of human spaceflight -- was a significant event for all peoples. It was a triumph of math, science, technology and engineering [...]

The Explosive (But Now Forgotten) Rumor About Yuri Gagarin

Alexis Madrigal, senior editor, The Atlantic: In the day after Yuri Gagarin's momentous ride into space, a strange story cropped in newspapers across the world. Sergei Bouterline, an MIT instructor, made the explosive claim that Gagarin was actually his nephew [...]

The Difference Between Exploring and Tourism

James Jorasch, founder, Science House: But what about the third man in space? Have you ever heard of Soviet Cosmonaut Gherman Titov? Although certainly a great man, he's unlikely to be popping up as the answer to a quiz show million dollar question [...]

Space Telemetry: How Extraterrestrials Phone Home

Tim Carmody, freelance writer: In 1945, Arthur C. Clarke believed that communications satellites were "a possibility of the more remote future -- perhaps half a century ahead." The idea that scientific measurements could be taken and computational commands [...]