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A famous physicist’s simple experiment showed the inevitability of the Challenger disaster

The space shuttle Challenger explodes shortly after lifting off from Kennedy Space Center in 1986. (AP)

On Jan. 28, 1986, the world watched in horror as NASA's Challenger shuttle disintegrated just 73 seconds into its flight. The disaster, which claimed the lives of five astronauts and two payload specialists, remains one of the deadiest accidents in the history of spaceflight, matched only by the 2003 explosion that precipitated the end of NASA's shuttle program.

With every step that humankind takes toward the stars, we remember the sacrifice of those seven individuals — Francis R. Scobee, Michael J. Smith, Ronald McNair, Ellison Onizuka, Judith Resnik, Gregory Jarvis and Christa McAuliffe — who gave their lives to the spirit of exploration and scientific inquiry. We remember them, and their bravery, and the bravery of others who still decided to dedicate their own lives to spaceflight. Every man and woman donning a spacesuit today has the memory of Challenger on their shoulders, and yet they fly — and push forward in hopes of visiting Mars and beyond.

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But on the eve of the tragedy's 30th anniversary, there are other scientists who should come to mind as well: The ones who worked tirelessly to figure out what had gone wrong so that changes would ensure it would never happen again.

Perhaps the loudest of these was Richard Feynman, a Nobel Laureate in physics who contributed to the Rogers Commission Report. Feynman didn't need to devote hours to calculations about the structural integrity of the shuttle in order to reach any conclusions about the cause of its disintegration. His brutally simple explanation is shown in the video below:

An old man, an O ring and a cup of ice water. A cup of ice water, representing the conditions in which the shuttle had been launched. They were colder temperatures than any in which the craft had ever been tested. And what may have seemed like a trivial few degrees spelled inevitable disaster for the crew once the Challenger lifted off.

Feynman was not a perfect man, and he remains one of the more problematic "heroes" of scientific history. But his work on the Rogers Commission Report — just two years before his death — was arguably his crowning achievement. He reportedly distanced himself from the government-affiliated authors involved, choosing instead to interview as many engineers involved in the project as he could. Feynman was so critical of NASA's role in the tragedy that his chapter of the report was shuffled to the appendix.

The scientist didn't mince words: He pointed out that NASA management ranked the safety of the shuttles thousands of times higher than the engineers did, which encouraged unrealistic launch timelines and a tendency to underestimate risky flight conditions.

Here’s the speech Ronald Reagan gave on the night of the Challenger disaster

"In any event this has had very unfortunate consequences, the most serious of which is to encourage ordinary citizens to fly in such a dangerous machine, as if it had attained the safety of an ordinary airliner," Feynman wrote, referring to the two payload specialists — an engineer and a teacher — trained specifically to fly on that single mission. NASA had even considered sending the actor known for portraying Big Bird on the show "Sesame Street" as an ambassador for schoolchildren back on Earth — but his costume was too cumbersome to wear onboard.

As recently as a few weeks ago, WIRED reports, NASA's Aerospace Safety Advisory Panel concluded that the agency is taking dangerous risks and, more importantly, failing to communicate those risks properly.

“Does one hand know what the other is doing?” panel member James Bagian, a former astronaut who now teaches at the University of Michigan, asked during an interview with WIRED. “If everyone doesn’t understand all the assumptions, and they use that as a foundation to make a decision, that can have a ripple effect.”

It's been a long time since NASA — or any space agency — suffered a tragedy. But it's also been a long time since we as a species attempted a crewed mission more complex than the journey to the International Space Station and back. That's going to change very soon: As early as 2025, NASA may send astronauts into "deep space" for the first time with a mission to an asteroid that has been redirected to orbit the moon. A mission to Mars may follow as quickly as the 2030s.

Feynman is far from a perfect hero, and NASA is far from an enclave of villainy. But the ease with which one scientist was able to formulate a damning takedown of the agency's behavior should serve as a reminder of the dangers of human error and hubris in endeavors as delicate as trips into space — especially in the days ahead.

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