The Space Shuttle Challenger Disaster

Podcast Transcript

On January 28, 1986, an event occurred that would be remembered by almost everyone alive at the time.

Seventy-three seconds into its flight, the Space Shuttle Challenger was destroyed by a violent explosion, killing all seven astronauts on board.

In addition to being seared into the minds of those who witnessed the tragedy, the disaster forever changed how space flights were conducted.

Learn more about the Space Shuttle Challenger Disaster, how it happened, and its aftermath on this episode of Everything Everywhere Daily.

Space Shuttle mission STS-51-L was scheduled to be the 25th flight of a space shuttle and the 10th flight of the shuttle Challenger.

By 1986, space shuttle launches might not have been routine, but they also weren’t special events anymore either.

STS-51-L was to be a special mission. It was scheduled to launch a satellite and make observations from space of Halley’s Comet.

Most importantly, the flight was to have the first teacher to be flown into space.

On the behest of President Ronald Reagan, in 1984, NASA unveiled the Teacher in Space Project. The Teacher in Space Project was to be pretty straightforward. Find teachers who were not astronauts but common civilians, send them to space, and when they return, they could then travel to classrooms to tell students about their experience.

Over 11,000 teachers applied for the Teacher in Space Project, and after several rounds of eliminations, the teacher selected to be the first in space was a high school social studies teacher from Concord, New Hampshire, named Christa McAuliffe.

McAuliffe was scheduled to teach two 15-minute lessons from space during the mission.

In addition to Chrisa McAulife, the other six astronauts were Commander Richard Scobee, Pilot Michael Smith, Mission Specialists Ronald McNair, Ellison Onizuka, and Judith Resnik, and Payload Specialist Gregory Jarvis.

In the lead-up to the launch on January 28, temperatures at Cape Canaveral were unusually low for Florida. The overnight temperatures before the launch dipped down to 18 °Farenheight or ?8 °Celcius.

The temperature at launch was 26 °Farenheight or ?3 °Celcius. It was going to be the coldest launch of a space shuttle flight in history.

The shuttle took off at precisely 11:38:00 a.m., with children watching at schools around the country because of the Teacher in Space Project.

Everything appeared to go fine for the first 73 seconds.

However, at T-minus 73 seconds, a massive explosion was observed. A large fireball and cloud of smoke were apparent, as were two trails of smoke left by the solid rocket boosters, which flew apart from each other in the shape of a Y.

All telemetry and data streaming from the shuttle back to mission control instantly ceased.

The spectators, including the family members of the crew, could do nothing but look on in horror as debris showered down from the sky.

The Space Shuttle Challenger Disaster was a seminal event for everyone who can remember it. I was a junior in high school at the time. I just came out of history class when I heard people talking about the space shuttle in the hallway.

A television was set up in one of the common areas for everyone to watch the news.

Almost immediately, NASA sent out the two ships which were regularly used to recover the solid reusable rocket boosters which landed at sea. This time, they were sent out to recover debris.

That evening, the President’s State of the Union speech was scheduled. For the first only time in history, the speech was postponed. Instead, he gave a televised address to the nation.

The big question now was, what exactly happened?

The first order of business was to recover as much of the spacecraft as possible.

By that evening, there were a dozen aircraft and eight ships searching for debris in the waters off the coast of Florida.

Within a few days, the navy was brought in to help with recovery efforts on the sea floor.

The debris was scattered over an enormous area, and the debris which floated could be carried by currents over an even larger area.

The recovery efforts took months. The priority for recovery was the solid rocket boosters and the crew compartment.

The crew compartment was found on March 1. What they discovered was that the bodies of the crew were severely damaged when the crew compartment hit the water.

During the recovery of the remains of the crew, the body of Gregory Jarvis actually floated away and wasn’t recovered until April 15.

Most of the remains of the crew were identified, but some were not, as this was in an era before genetic testing was available. Identifiable remains were transferred to the families, and the unidentifiable remains were interred at the Space Shuttle Challenger Memorial in Arlington National Cemetery.

The pieces of debris were stored in two abandoned Minuteman missile silos located at Cape Canaveral Air Force Station, where the debris remains to this day.

Currently, 118 tons of debris, representing 47% of the vehicle, have been recovered.

The investigation into the disaster was conducted by a blue ribbon presidential commission led by former United States Secretary of State and Attorney General William Rogers. The commission became known as the Rogers Commission.

Other members of the commission included the likes of Neil Armstrong, Sally Ride, Chuck Yeager, and Nobel laureate Richard Feynman.

The commission was rather quickly able to determine exactly what happened. Photographic evidence, recovered debris, and historical documents all pointed to the same conclusion.

The cause of the disaster had to do with the rubber seals in the side solid rocket boosters, which were called O-rings.

The solid rocket boosters had segments that were stacked on each other vertically. The O-rings were gaskets that were placed between the sections to provide a gas-tight seal.

When the solid rocket fuel inside the booster was ignited, it would produce extremely hot gasses, which you wanted to go out the nozzle of the rocket, not out the sides.

The problem had to do with the extremely cold temperatures the day of, and the night before, the launch.

The rubber used to make the O-ring became rigid and more brittle under cold temperatures. When the temperatures dropped, the O-ring ceased to provide an airtight seal.

The most famous moment from the committee’s hearings was when Richard Feynman took a portion of the O-ring material and dipped it in ice water. Once it was put it cold water and deformed, it didn’t go back to its original shape.

As it turned out, there was black smoke emanating from the right solid rocket booster moments after it was ignited. The problem with solid rocket fuel is that once it is lit, you can’t turn it off.

The hot gas coming out of the side of the rocket booster eventually turned into a flame thrower pointed directly at the large external fuel tank, which contained liquid hydrogen, and the strut that connected the solid fuel rocket booster to the external fuel tank.

In an almost simultaneous action, the solid fuel rocket booster broke away when the connecting struct was destroyed and burned through the liquid hydrogen tank. The liquid hydrogen tank was slammed into the liquid oxygen tank, causing a massive explosion.

Believe it or not, the explosion was not responsible for the destruction of the shuttle itself. That was caused by the aerodynamic forces of traveling at close to Mach 2. The high speeds in the atmosphere tore the orbiter apart.

If you go online, you can see very clear images of flame and smoke coming out of the solid rocket booster at various stages of the flight.

The exact cause of death of the astronauts still remains unknown. It wasn’t known if it was the initial destruction of the orbiter, the loss of oxygen, or the final impact with the water which was responsible for their deaths.

It is known that at least some of the astronauts survived the initial breakup of the shuttle as the crew compartment was intact.

The discovery of the failure of the O-ring was only the tip of the iceberg.

The truly shocking part of the committee’s findings was that the problem was initially identified in 1977. The manufacturer of the solid rocket boosters was Morton Thiokol. NASA engineers had identified the problem as a potentially catastrophic one, but Morton Thiokol never did anything, and NASA never made fixing the problem a priority.

Just before the launch, several Morton Thiokol engineers advised that the launch shouldn’t take place with temperatures below 53 degrees Fahrenheit. However, Morton Thiokol’s management talked among themselves and officially advised NASA that it was ok to launch.

It wasn’t just this one issue with the solid rocket booster O-rings. What was found was an entire culture that massively underestimated risks and safety at NASA, especially at the managerial level.

Administrators at NASA had placed the estimate of a disaster of a space shuttle at 1-in-100,000, which is absurd given the complexity of the space shuttle.

There were many changes that came from Space Shuttle Challenger Disaster.

For starters, the President supported the creation of a new space shuttle to replace Challenger, which was named Endeavor. It first flew in 1992.

The US House Committee on Science and Technology conducted its own investigation, which supported the conclusions of the Rogers Commission.

The entire space shuttle program was grounded for two years and eight months as changes were made to fix the problems with the solid rocket boosters and other critical problems with the space shuttles.

NASA created the ??Office of Safety, Reliability, and Quality Assurance. Its director was directly responsible to the NASA administrator and could act independently to ensure the safety of any future mission.

However, after the Space Shuttle Colombia disaster in 2003, a commission that looked into that disaster concluded that the changes made after the Challenger disaster were insufficient.

The Teacher in Space Project ended. However, Christa McAuliffe’s backup for STS-51-L was an elementary school teacher from Idaho named Barbara Morgan. Morgan continued to train as a mission specialist at NASA and eventually did fly into space on STS-118 in 2007, thus finally becoming the first teacher in space, 21 years after the Challenger Disaster.

There have been numerous monuments and memorials to the Challenger astronauts, including the naming of asteroids and craters, as well as parks and schools.

Today, there are still pieces of Challenger that are being discovered. SCUBA divers discovered a 20-foot-long piece of the shuttle on the sea floor in November 2022. Newly discovered pieces are placed in the same silo as the pieces recovered in 1986.

There is a section of Challenger that is on permanent display at the Kenedy Space Center.

Even though it would take another 25 years to unwind, the Challenger explosion marked the beginning of the end of the space shuttle program. The disaster showed that the initial turnaround times, reusability, and cost savings of the space shuttle would never materialize.

The added safety precautions and inspections involved in every flight after Challenger only made things worse.

The Space Shuttle Challenger Disaster was one of those few moments in history where everyone remembers where they were when they heard about it. It was and will remain one of the greatest tragedies in the history of human space flight.