Spaceflight Insider

Our Spaceflight Heritage: Remembering Challenger

STS-51-L space shuttle Challenger launches from Kennedy Space Center's Launch Complex 39 in January pf 1986. NASA photo posted on SpaceFlight Insider

This year marks the 30th anniversary of the final flight of Space Shuttle Challenger. Photo Credit: NASA

On Jan. 28, 1986, a “routine” shuttle launch turned into a monumental tragedy that forever altered the course of the Space Shuttle Program, and from which NASA – and the nation – never fully recovered.

STS-51L was the tenth mission for the Space Shuttle Challenger and the 25th mission of the Space Shuttle Program. The names of Challenger’s final crew is forever inscribed in America’s collective memory: Commander Dick Scobee. Pilot Mike Smith. Mission Specialists Ellison Onizuka, Judy Resnik, Ronald McNair, Greg Jarvis, and New Hampshire schoolteacher Christa McAuliffe.

Launch of Space Shuttle Challenger on STS-51L NASA photo posted on SpaceFlight Insider

Challenger ascends on its final mission – STS-51L. Photo Credit: NASA

Unlike previous shuttle flights, STS-51L launched from Pad B at Kennedy Space Center’s Launch Complex 39. Before STS-51L, all prior shuttle missions had launched from Pad A.

Also during that time, the U.S. Air Force planned on launching shuttles from its own launch complex on the West Coast. Located at Vandenberg Air Force Base in California, Space Launch Complex 6 was deactivated after the Challenger accident. It would find new life launching Titan 34D and Titan IV rockets before eventually being used as the West Coast launch site for the Delta IV family of boosters.

Due to the planned dual launch sites, the Shuttle Program used a rather confusing nomenclature system for shuttle flights that took place between 1984 and ’85. STS-51L was the twelfth flight of the fiscal year 1985; hence 5 for 1985, 1 for site 1 – Kennedy Space Center – and L to designate the twelfth flight.

As noted, after Challenger, the Air Force’s plans for their own shuttle launch site were canceled, and NASA returned to, essentially, sequentially numbering their flights. Therefore, the next mission after STS-51L was STS-26.

STS-51L had been delayed three times: the first time due to delays in preparing another shuttle mission, STS-61C; the second time because of bad weather at the abort landing site in Dakar, Senegal; and the third because of high crosswinds at the Shuttle Landing Facility (SLF) at KSC.

Jan. 28 of 1986 was a particularly cold morning. Temperatures dropped to 30 °F (–1 °C) overnight. Engineers, notably Roger Boisjoly at Morton Thiokol, expressed concerned about the O-rings in the Solid Rocket Boosters (SRBs), which were meant to seal the individual sections and prevent the super-hot gasses within from escaping. On previous flights, the O-rings had suffered serious damage, but because the damage had never resulted in catastrophe, the damage, called “blow-by”, was considered by the Mission Management Team (MMT) as normal – and acceptable.

Rogers Commission member and theoretical physicist Richard Feynman. Photo Credit: Tamiko Thiel

Rogers Commission member and theoretical physicist Richard Feynman. Photo Credit: Tamiko Thiel

Boisjoly was concerned about the cold weather on the morning of Jan. 28. He feared that the O-rings could become brittle and fail. Morton-Thiokol arranged a phone conference with NASA to express their concerns. But given time to consider whether to recommend delaying the flight, engineers said their findings were inconclusive, and the launch was approved.

Seventy-three seconds into the flight, Challenger exploded in the sky above Florida in front of thousands of horrified onlookers.

As Boisjoly had feared, the O-rings failed. The accident investigation board, headed by William P. Rogers, former secretary of state under President Richard Nixon, included astronauts Neil Armstrong and Sally Ride, as well as legendary test pilot Chuck Yeager, and physicist Richard Feynman. The Rogers Commission Report not only concluded that the accident was caused by the O-rings failing in the abnormally cold weather, but also that there was a frightening disconnect between NASA engineers and management.

Feynman famously demonstrated the failure of the O-rings by dipping a sample of the material in ice water. “I took this stuff that I got out of your seal and I put it in ice water,” Feynman said, “and I discovered that when you put some pressure on it for a while and then undo it, it does not stretch back. It stays the same dimension. In other words, for a few seconds at least and more seconds than that, there is no resilience in this particular material when it is at a temperature of 32 degrees.”

When NASA grounded the shuttles after the Challenger accident, the Reagan Administration ordered NASA to withdraw from the commercial satellite industry. This opened up the commercial market to companies like Ariane. Facing competition from uncrewed rockets, there was little justification for the Space Shuttle Program post-Challenger apart from constructing the International Space Station. From that standpoint, it has to be said that, although the Space Shuttle was not retired until 2011, the tolling of its funeral bell first sounded on Jan. 28, 1986.

Since that cold, fateful day, NASA has returned to flight not once, but twice. Each time, the agency took what it learned from those painful lessons and implemented them into an improved shuttle orbiter. In 2011, after some 30 years of service, the three surviving orbiters, Atlantis, Discovery, and Endeavour were retired.

Perhaps the most enduring legacy of the Challenger accident is a quote by Rogers Commission member Richard Feynman, who focused in on the fact that concerns of a public relations nature should never trump those originating from a technical or safety standpoint.

“For a successful technology, reality must take precedence over public relations, for nature cannot be fooled,” Feynman said.

Video courtesy of RichardFeynmanLove


Collin R. Skocik has been captivated by space flight since the maiden flight of space shuttle Columbia in April of 1981. He frequently attends events hosted by the Astronaut Scholarship Foundation, and has met many astronauts in his experiences at Kennedy Space Center. He is a prolific author of science fiction as well as science and space-related articles. In addition to the Voyage Into the Unknown series, he has also written the short story collection The Future Lives!, the science fiction novel Dreams of the Stars, and the disaster novel The Sunburst Fire. His first print sale was Asteroid Eternia in Encounters magazine. When he is not writing, he provides closed-captioning for the hearing impaired. He lives in Atlantic Beach, Florida.

Reader Comments

I was a career NASA emplyee at KSC, a shuttle PVD engineer at the time. I had actually taken a two year transfer to VAFB for shuttle preparations but was back at KSC on a trip that day. I was out in the parking lot immediately south of the VAB that cold January morning. When I saw the two SRBs flying separately away from the orbiter/ET I knew it was a major disaster. One of the SRBs deployed its recovery chute and I recall hearing someone nearby shout “They are parachuting out” which I knew was impossible. It was at that time the significance of what had happened started to hit. We spent the remainder of the day in our offices watching the news reports because that was the only source of information. My lead engineer had been on the console in the firing room and they locked down the firing room for 3 or 4 hours carefully collecting all the documentation they could find. When a major catastrophe like this happens NASA goes into a lock down mode securing all the data and it becomes an extended operation inspecting everything with a fine tooth comb for any problems. While it might be obvious what caused an accident they look at everything that happened during the entire processing operation for any contributing factors. I returned to VAFB a couple of days later but the operations out there were terminated within 6 months and then I returned to KSC to finish my career after the final shuttle mission. When Columbia crashed we did a similar investigation and I found out far more in depth what KSC had done the first time pouring over every procedure and operation in depth looking for any problems that might have been missed during processing. Ultimately both disasters could easily be pinpointed to management negligence on major issues already revealing themselves in their drive to fly shuttles in an “operational” environment.

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