Summary
Overview
Hannah Fry and Michael Stevens explore unconventional methods of reaching space, from nuclear explosions to space elevators. They discuss the fastest (a 1957 manhole cover blown off a nuclear test), slowest (waiting billions of years for Earth's eventual journey through space), and most practical future alternatives to expensive rockets, including launch loops and skyhooks that could revolutionize space access.
The Fastest, Cheapest, and Worst Way to Space
The hosts introduce the episode's theme by revealing that one answer satisfies all three categories: a steel manhole cover launched during Operation Plumbob in 1957. This 900-pound cap was blown off a nuclear test at an estimated 67 kilometers per second—six times Earth's escape velocity—making it potentially the fastest human-launched object ever, though it almost certainly vaporized in the atmosphere. While the nuclear test was expensive, the manhole cover itself didn't have to pay, making it technically the cheapest passenger to space.
- Operation Plumbob in 1957 involved underground nuclear explosions with a steel cap sealing the borehole
- The 2,000 kilogram manhole cover appeared in only one camera frame, traveling at approximately 150,000 mph (67 km/s)
- This speed was six times Earth's escape velocity, making it the fastest launch from Earth's surface
- The manhole cover almost certainly didn't survive, being ablated and burned up in the atmosphere
" The cheapest, fastest, and worst way to go to space would have been to have been a borehole cover in 1957 during Operation Plumbob. "
The Slowest Method: Just Wait
Michael presents a fascinating thought experiment about the ultimate destiny of matter in the universe. Over incomprehensibly long timescales—from billions to undecillions of years—Earth will likely be ejected from the solar system, then the galaxy, and eventually all matter may decay into radiation traveling through intergalactic space. This represents the slowest but most certain way your atoms will eventually journey through space, requiring patience on a cosmic scale that dwarfs the current age of the universe.
- In 7-8 billion years, the sun will become a red giant and possibly engulf Earth
- Within 10 quadrillion years, Earth will likely be ejected from the solar system by passing stellar remnants
- Within 10 quintillion years, Earth could be ejected from the Milky Way galaxy or absorbed into a supermassive black hole
- Within 100 undecillion years, protons may decay, turning all matter into radiation traveling through space
" Your body's ultimate destiny is to be in interstellar space. It's just going to take a really long time. "
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