Travel the universe with Dr. Ethan Siegel as he answers the biggest questions of all
The sacrifices of early astronauts paved the way for Apollo’s successes, and so much more.
In all of history, only 24 humans have ever escaped Earth’s gravity.
The very first launch from NASA’s Cape Kennedy space center was of the Apollo 4 mission. Although it accelerated no faster than a sportscar, the key to its success was that the acceleration was sustained for so long, enabling payloads to escape Earth’s atmosphere and enter orbit. Eventually, multi-stage rockets would enable humans to escape the gravitational pull of the Earth entirely. The Saturn V rockets later took humanity to the Moon. (NASA)
From 1968 through 1972, the crews of Apollo 8 through 17 voyaged to the Moon.
It has been more than 50 years since humanity first set foot on another world: our Moon. This photo, from the Apollo 15 mission, was taken by one of only 24 people (and of another one of those 24) to ever travel beyond low-Earth orbit. Of these 24, all survived the journey, but only 10 remain alive today. (NASA / APOLLO 15)
The customs form filled out by the Apollo 11 astronauts returning from the Moon. What seems like an unnecessary formality today was an essential part of record-keeping, particularly in the early days where it was not yet certain that there were no active forms of life on the Moon that could be possibly infectious to Earth-based life. (NASA / US CUSTOMS & IMMIGRATION)
Ted Freeman, US Air Force Captain, was the first NASA astronaut to perish in training. A 1964 accident involving a T-38 Talon aircraft claimed his life, as it later did to three other astronauts prior to the start of the Apollo program, including the original prime crew for the Gemini 9 mission. (NASA (L), ANNE CADY (R))
View of a United States Air Force Northrop T-38 Talon jet trainer in flight, from the 1960s. Since 1959, the T-38 Talon has been a mainstay in terms of flight trainers for various branches of the military and government, including the Air Force and NASA. Four separate astronauts, Theodore Freeman, Charles Basset, Elliot See and Clifton Williams, were killed in training using this plane from 1964–1967. (US Air Force/Interim Archives/Getty Images)
From left to right, Apollo 1 astronauts Roger Chaffee, Ed White, and Gus Grissom lay supine in the capsule simulator for their upcoming mission. This photo, taken in January of 1967, was supposed to be in preparation for the first successful launch of the Apollo era. Instead, a fire during a subsequent test set the Apollo program back by nearly a full calendar year, killing all three astronauts but leading to extremely valuable knowledge, albeit at the ultimate price. (NASA VIA GETTY IMAGES)
The tragic lessons learned helped ensure the safe return of all subsequent Apollo crewmembers.
This iconic image, of NASA mission control in 1970, celebrates the successful splashdown of the returning Apollo 13 astronauts. Director at Mission Control, Gene Krantz, with his infamous buzzcut hairstyle, can be seen prominently at center, while others light up cigars in celebration. (NASA)
All 24 astronauts that journeyed to the Moon — including 12 moonwalkers — survived.
The crew of Apollo 11 — Neil Armstrong, Michael Collins, and Buzz Aldrin — in the Mobile Quarantine Facility after returning from the surface of the Moon. The U.S.S. Hornet successfully recovered the astronauts from the Command Module after splashdown, where the crew was greeted by President Nixon, among others. (NASA)
This unfamiliar scene shows a small region of the Moon’s ‘day’ side from the perspective of Michael Collins aboard Apollo 11. For the entirety of the duration of Armstrong and Aldrin’s historic first steps on the Moon’s surface, Collins was alone, orbiting the Moon, losing radio contact with everyone for 45 minutes out of every revolution. (NASA / APOLLO 11 / MICHAEL COLLINS)
The orbiting module went 45 minutes without human contact during each revolution.
The Apollo mission trajectories, made possible by the Moon’s close proximity to us. Newton’s law of universal gravitation, despite the fact that it’s been superseded by Einstein’s General Relativity, is still so good at being approximately true on most Solar System scales that it encapsulates all the physics we need to travel from Earth to the Moon and land on its surface, and return. (NASA’S OFFICE OF MANNED SPACE FLIGHT, APOLLO MISSIONS)
The lunar lander can be seen returning to the orbiting module with the Earth and Moon in frame, from Apollo 11. Michael Collins, on board and taking the photo, was the ‘loneliest human’ in existence for a time, being alone and behind the Moon, cut off from all other humans, for 45 minutes at a time with every revolution. (MICHAEL COLLINS / NASA / APOLLO 11)
When is the Moon not a Moon? When it’s composed entirely of text. Here, the entire text transcript of the Apollo 11 mission is laid out in such a way that it reproduces the features of the mission target: the Moon. Based on an image of the Moon taken by astrophotographer J-P Metsavainio, the text was composited to create this interesting artistic interpretation and tribute to the Apollo 11 mission and its crew. (J-P METSAVAINIO / ASTROANARCHY)
Detail of Finnish astrophotographer and artist J-P Metsavainio’s Apollo 11 tribute. By taking an image that he himself composed of the Moon’s near side and the transcript of the entire Apollo 11 mission, Metsavainio has created a ‘voices of Apollo 11’ artistic masterpiece to immortalize the mission and its target forever. (J-P METSAVAINIO / ASTROANARCHY)
This is one of the final official appearances of all three Apollo 11 astronauts: Buzz Aldrin, Michael Collins, and Neil Armstrong. Armstrong died in 2012, while Collins died in 2021. Buzz Aldrin remains one of 10 Apollo-era astronauts to still survive to the present day. (NASA / GETTY IMAGES NORTH AMERICA)
At age 85, Ken Mattingly is the youngest remaining among them.
Apollo 16 astronauts Charles Duke (still alive), John Young (died 2018) and Ken Mattingly (still alive) after splashing down in the Pacific Ocean following their successful mission to the Moon. Mattingly is the youngest living astronaut to travel to the Moon, while Duke is the youngest living to walk upon it. (Space Frontiers/Getty Images)
Mostly Mute Monday tells an astronomical story in images, visuals, and no more than 200 words. Talk less; smile more.
MIT Scientist Jason Soderblom describes how the NASA mission will study the geology and composition of the surface of Jupiter’s water-rich moon and assess its astrobiological potential.
