StMU Research Scholars

Space Shuttle Challenger Disaster: Accident or Negligence?

On the evening of January 27th, 1986, an engineer at a little-known company told his wife, “It’s going to blow up.” That man was Bob Ebeling, an engineer for Morton Thiokol, which had been contracted to manufacture and maintain the solid rocket booster (SRB) used by NASA’s space shuttle program. On that night, he and his coworkers tirelessly pleaded with NASA officials to delay the launch of the space shuttle Challenger until temperatures were more favorable. Sadly, NASA officials did not heed these warnings, and all seven crew members of STS 51-L lost their lives.1

This story starts before that tragic day with the creation of the space shuttle program. As you can imagine, any vehicle designed for space undergoes rigorous testing and analysis before being put into use. During these early tests, engineers at the Marshall Space Flight Center saw a potentially catastrophic flaw in the two o-ring design that the SRB used in its joints and reported their concerns to NASA in 1971. NASA disregarded these concerns and did not pass this report onto Morton Thiokol for further evaluation. NASA approved the shuttle program and put the shuttles into production. By the second shuttle mission, there was serious evidence that supported the original concerns for the SRB o-ring failure. The evidence continued to stack up with each subsequent mission. In 1985 Morton Thiokol decided to redesign the joint to include an additional three inches of steel, which would grip the inner face of the joint and prevent it from rotating and potentially failing. Both NASA and Morton Thiokol agreed to continue with the launch schedule while they worked on this fix and accepted the potential for failure as an acceptable flight risk.2

Despite this risk, no shuttle had ever suffered a catastrophic failure during launch, orbit, re-entry, and no crew member had ever been injured or killed during a mission. The Challenger had already completed nine successful missions at this point and future missions were continuously being planned. This perfect record was a point of pride for NASA, and confidence continued to grow. This confidence caused NASA to be overly optimistic in their promise of how cost effective and efficient the shuttle program could be. These promises resulted in immense pressure from the government and tax payers to deliver on their promises with an overly ambitious launch schedule.3

The launch of STS 51-L had been planned as the first launch of 1986, and it would also put the first teacher in space. The addition of Christa McAuliffe, an elementary school teacher from New Hampshire, to the mission had garnered national and international attention. The launch was scheduled for January 22, 1986, but due to the delay of other missions, the launch of 51-L was pushed back several times — first to January 23rd, then to the 24th, 25th, 26th, and finally the 27th. On the morning of the 27th during regular countdown procedures, a micro switch indicated a failure of an exterior hatch-locking mechanism. By the time this issue was fixed, the winds had exceeded launch criteria. The launch was delayed yet again.4

Buildup of ice on the shuttle and launch pad the morning of Jan. 28th, 1986. The cold weather was ultimately what caused both o-rings to fail. | Courtesy of Wikimedia commons and NASA

Managers at Morton Thiokol had been watching the delays from their headquarters in Utah and were tracking the conditions with each delay. On the evening of the 27th, they saw the temperature would be below freezing at the launch site the next morning, which presented potential problems, raising concern. The shuttle and SRB had never been certified to operate in temperatures that low. Bob Ebeling had written an official memo for NASA titled “Help!” in 1985 where he described the extremely high potential for both o-rings to fail in temperatures below 40°F, but NASA had ignored it. That evening a manager at Morton Thiokol called Ebeling to ask if the shuttle could launch the following morning in the freezing temperatures. When Ebeling informed them of the extreme risk, they immediately started crunching the numbers and building their argument for the delay of the launch. Morton Thiokol and NASA held a teleconference. NASA opposed all arguments for a delay, and stated that if one o-ring failed there was a secondary mechanism that would stop a catastrophic failure from happening. Morton Thiokol engineers continued to explain that was an incorrect assumption that would surely lead to disaster. Sadly, NASA officials disagreed, and a second teleconference was scheduled. Except this time, the Morton Thiokol engineers were excluded, only management from NASA and Morton Thiokol were included. In this second call Morton Thiokol management disregarded the warnings of their own engineers and recommended that the launch proceed as scheduled.5

The Challenger shuttle being transported to the launchpad before its final fatal flight. | Courtesy of Wikimedia commons and NASA

At 11:38AM on January 28th, 1986, STS 51-L launched from Cape Canaveral, Florida. On board were seven crew members: Francis Scobee, Michael Smith, Ronald McNair, Ellison Onizuka, Judith Resnik, Gregory Jarvis and Christa McAuliffe. At 11:39:13AM, just 73 seconds after launch, the space shuttle Challenger broke apart at an altitude of 14,000 meters. All crew members were killed when their cabin plummeted into the Atlantic Ocean three minutes after the break up.6

This disaster led to the immediate grounding of all shuttle missions. President Reagan convened a commission, called the Rogers Commission, to investigate the Challenger disaster. The results of the investigation showed the mechanical cause of the break up was a failure in both o-ring seals, which led to catastrophic structural failure. The report more importantly considered the contributing causes of the accident. It concluded that both NASA and Morton Thiokol failed to respond adequately to the potential danger of the SRB design, and instead of taking immediate action they accepted it as a flight risk. It also uncovered the large disconnect between management and engineers, which led to people who didn’t truly understand the science and math making a decision that was based on pride instead of fact.7

The seven crewmembers of the ST-51L mission. Front row: Michael J. Smith, Dick Scobee, Ronald McNair. Back row: Ellison Onizuka, Christa McAuliffe, Gregory Jarvis, Judith Resnik. | Courtesy of Wikimedia commons and NASA

These tragic events unfolded more than three decades ago but are relevant today more than ever. The first private civilian space mission is rapidly approaching, and as it draws closer, we have to look closely at our past mistakes. If we don’t we are destined to repeat them. The millions who watched these events unfold have not forgotten how horrified they were, and they also remember how much the nation was shaken from this tragedy. Ebeling sums these feelings up best when describing how he feels looking back at what happened, “I could have done more. I should have done more.”8  We need to do our best to get everything right the first time, especially when failure equates to lives lost. We need to continue to focus on this as space travel becomes more prevalent in our society, and like Morton Thiokol and NASA in the ’80s, we can’t value our pride more than human lives.


  1. Howard Berkes, “30 Years After Explosion, Challenger Engineer Still Blames Himself,” NPR, January 28, 2016,
  2.  Wikipedia, 2018, s.v. “Space Shuttle Challenger Disaster,”
  3. Howard Berkes, “30 Years After Explosion, Challenger Engineer Still Blames Himself,” NPR, January 28, 2016,
  4.  Diane Vaughn, The Challenger Launch Decision: Risky Technology, Culture and Deviance at NASA, Enlarged Edition (Chicago, IL: University of Chicago Press, 2016), 1-3.
  5.  Wikipedia, 2018, s.v. “Space Shuttle Challenger Disaster,”
  6.  Funk & Wagnalls New World Encyclopedia, 2017, s.v. “Challenger Disaster.”
  7.  Wikipedia, 2018, s.v. “Space Shuttle Challenger Disaster,”
  8. Howard Berkes, “30 Years After Explosion, Challenger Engineer Still Blames Himself,” NPR, January 28, 2016,

96 Responses

  1. This article was very insightful, and I enjoyed reading it. I like most people, know of the basics behind the challenger disaster, but not a lot of detail as to why the events that occurred that day occurred. After reading this article I have a better understanding of the events and as many have stated before me how it was preventable. As the title suggests the image that has been presented to society is how this tragic event was an accident, but once you have a better understanding of the incident it feels like negligence on how NASA dealt with the situation.

  2. I’ve heard about the Challenger disaster and after reading this article, I find it even sadder now that I know that it was ultimately a preventable event. Not only could the event have been prevented, but those at NASA (engineers and the officials) knew that the Challenger was going to blow up. this made the situation all the more heart wrenching knowing that they put the astronauts lives in danger and ultimately led them to their deaths just because they chose to ignore the obvious warning signs and concerns from engineers.

  3. I can see why this article was nominated for an award, This article goes really in depth on how preventable this tragedy was, the warnings given seem to have just been ignored or caught up in the system. despite the best efforts of NASA engineers like Bob Ebeling and others, the disaster still occurred due to the fatal flaw within the O-Rings.

  4. I think one of the worst parts of this story other that the shuttle exploding of course is just the fact that they new it was going to happen. When I read that line my heart felt like it dropped. It truly was one the saddest lines I think I have ever read. It makes me really upset to read that this situation could have been avoided.

  5. I have heard of this tragedy before and it saddens me to hear about it because there could have been something done to prevent this from happening. This could have been avoided and lives would not have been lost. Through this tragedy though, important lessons were learned to trust the facts and don’t brush them aside. It is always best to prepare for the worst to prevent the worse possible outcome from occurring.

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