Editor’s note: This story contains discussion of astronaut fatalities and dangerous moments in human spaceflight.
It was 40 years ago today (Jan. 28) that the space shuttle Challenger blasted off on its 10th mission to space. Sadly, the vehicle never made it there.
Ron Doel, who is today a professor of history at Florida State University, was at NASA’s Jet Propulsion Laboratory (JPL) in Southern California that day. He was watching the Challenger launch on TV while awaiting JPL’s daily news briefing about Voyager 2, a NASA spacecraft that had just flown by Uranus.
“The shock was visceral, immediate,” Doel told Space.com by email. Perhaps it was all the more so for him, as an unusual set of circumstances lined up to bring Doel there: he was then a Ph.D. candidate in the history of science program at Princeton University, on a quick visit to learn more about Voyager. Doel had press credentials at JPL through some connections secured through an earlier book contract, allowing him to watch the reporters there react in real time.
“Monitors in the press room that had been showing in real time images transmitted from Voyager now showed, over and over, the launch and explosion,” he said. “Some in the press raced out of JPL with new assignments. The Voyager briefing was canceled. NASA officials, as I recall, gave us a briefing on the accident later in the day.”
The aftermath
An independent board, often called the Rogers Commission after its chair William P. Rogers, investigated the Challenger accident and found that it was caused by a combination of factors. The 260-page report cannot be summarized in a few words, but one of the more famous lines is this: “The decision to launch the Challenger was flawed.” Not only were there technical problems (most famously, an “O-ring” seal failing due to unusually cold conditions), but decision-makers made several assumptions that turned out to be unwarranted.
Sadly, Challenger didn’t remain the lone space shuttle tragedy. Seventeen years later came the breakup of the space shuttle Columbia during reentry on Feb. 1, 2003, killing another seven astronauts. That sparked a new query called the Columbia Accident Investigation Board. That Board produced a two-volume report, which also found that a set of technical and human failures led to the astronauts’ deaths.
“Columbia I remember in a lot of detail, because at the time I was a volunteer at the Boston Museum of Science,” recalled Pauline Barmby, today a department chair of physics and astronomy at Canada’s Western University, whose faculty include astronaut trainers and space instrument/experiment designers. Barmby also served as a team member on one of the instruments for NASA’s Spitzer Space Telescope.
“They [the museum] were planning on doing a live coverage of the landing,” Barmby told Space.com. But television stations instead only had live shots from Texas showing the shuttle’s debris trails as it broke up. “I recall vividly the person who was to be the presenter just broke down.”
Other fatalities in spaceflight include the Apollo 1 launch-pad fire on Jan. 27, 1967, which killed three astronauts; the crash-landing of the Soviet Union’s Soyuz 1 spacecraft that killed its single cosmonaut on April 24, 1967; and Soyuz 11, whose three cosmonauts died during reentry (due to depressurization) on June 29, 1971. (This list is not comprehensive; it doesn’t include all training fatalities, for example.)
There have also been numerous close calls over the years, including in recent memory. For example: European Space Agency astronaut Luca Parmitano experienced a water leak in the helmet of his NASA spacesuit while spacewalking outside the International Space Station (ISS) in 2013. And suspected debris strikes damaged crewed spacecraft docked to both the ISS and China’s Tiangong space station, forcing vehicle swaps for astronauts originally scheduled to come home on Russia’s Soyuz-MS 22 spacecraft and China’s Shenzhou 20 capsule. Everything worked out in both cases; the spaceflyers landed safely in September 2023 and November 2025, respectively.
As the above examples show, human spaceflight is risky. Each incident is investigated and reported on by the responsible entity, with the idea to prevent similar issues from arising in the future. But sometimes, the unexpected happens. Professional astronauts at any agency would likely tell you that they are prepared, both in training and in mindset, to be ready for the worst. But with more missions launching to space than ever these days, including with private citizens, what lessons can we think about to keep flying?
Lessons learned
In the not-too-distant past, a rocket might launch to orbit every few weeks or so. But these days, we see launches every few days — and often even more frequently than that. There is a safety challenge here, and it increases with launch cadence: Issues are often identified with the aid of hindsight, and the public doesn’t necessarily have insight into how decisions were made until they are probed by after-the-fact investigatory boards.
But NASA embraces a complex set of factors on every critical spaceflight decision, especially those regarding crewed missions. For example, the agency looks at past incidents to see “lessons learned,” which can help prevent issues in the future. NASA also examines spaceflight hardware, listens to experts and brings in outside voices on some decisions, just to name a few considerations.
Agency officials emphasized in a Jan. 16 press conference that everyone is very careful in green-lighting the launch of crewed missions, such as the forthcoming Artemis 2, which will send four astronauts around the moon as soon as Feb. 6.
We got some insights into that safety-first mindset during that briefing. A reporter asked why NASA was going ahead with simultaneous launch preparations for Artemis 2 and SpaceX’s Crew-12 astronaut mission to the ISS, which is currently targeted for Feb. 15.
“This is not a rush,” replied Jeff Radigan, NASA’s lead flight director for Artemis 2.
“It’s not prudent for us to put both those [missions] up at the same time, but we also have to ensure that both of them are ready to go,” he added. “We may run into an issue, and the last thing we want to do is make a decision too early and then lose an opportunity.”
Florida State University’s Doel noted that making the right call all the time is both “hard, and dangerous” but also said that “people can fix problems in tech systems over time.” That said, he added, “‘lessons learned’ is difficult, isn’t it, since the systems themselves are not static but continually evolving. We’re not using Apollo technology anymore; lessons won’t necessarily apply.”
Faster, better, cheaper?
Satellites are smaller and cheaper to launch than they used to be, and more industries than ever depend on space for military monitoring, Earth observation and telecommunications, among other applications. A huge roster of private companies — famously led by SpaceX — have cashed in on the demand.
While the experts Space.com talked to were careful not to lay blame or praise on any particular space entity for its safety practices, they said in general that there’s pressure on the system that should be acknowledged by anyone in space engineering.
“The joke about space missions is, they don’t get launched until there’s a pile of paperwork that’s as high as the rocket,” Western University’s Barmby said. “There’s an enormous amount of testing, and you make one minor change and you test to make sure that everything works the same way it did before, and then you make one more change. There’s an enormous amount of testing and documentation that happens before launch. But there is also a recognition that there’s some things that you cannot test, and you will only see what happens once you’re actually in space.”
Doel, as professors often do, also recommended further reading about systems under pressure — for example, anything by Thomas Hughes on technological systems; Barbara Keys’ work on the role emotions play in decisions, such as “Personal and Political Emotions in the Mind of the Diplomat” (2019); Edward Tenner’s “Why Things Bite Back: Technology and the Revenge of Unintended Consequences” (1997); and Diane Vaughn’s “The Challenger Launch Decision” (1996).
With more spaceflight activity happening generally, private companies are taking on more and more responsibility for missions as well. SpaceX, Blue Origin, Boeing and Virgin Galactic have all launched humans to space recently. A few of their missions have had issues, however.
For example, Blue Origin has suffered a partial failure and a full failure of its New Shepard suborbital vehicle, both times during uncrewed flights. Virgin Galactic had a pilot fatality during a test flight in October 2014. And even SpaceX, which is famously prolific and technically adept in launching people and satellites safely, has had a few hiccups — a tiny handful of Falcon 9 rocket launches or landings have failed over the past decade, requiring investigations that briefly grounded the fleet.
None of the Falcon 9 issues unduly affected crewed missions or kept Elon Musk‘s company on the ground for long. But some critics say there’s a vulnerability in having as much riding on one company’s rockets as the U.S. government does with SpaceX.
In 2024, Boeing’s Starliner spacecraft launched on its first-ever crewed flight, a test mission that sent two NASA astronauts to the ISS. But a number of issues cropped up en route, ultimately leading NASA to bring Starliner home uncrewed. The two astronauts, Butch Wilmore and Suni Williams, came back to Earth on board a SpaceX Crew Dragon capsule about nine months after their originally expected return date. Starliner also experienced issues on its two previous flights, which were uncrewed test missions to the ISS.
The experts interviewed for this article were careful to stress that they are outsiders to the decision-making processes for human spaceflight. But Barmby said she likes a bit of wisdom offered up by a high-profile insider — retired Canadian Space Agency astronaut Chris Hadfield, whose words she paraphrased. “Your first job is to not make things worse,” she said. “In many of these … the situation was not, ‘We’ve got to decide in the next 10 minutes.’ It’s, ‘We’ve got to decide in the next couple of days.’ So I think the lesson there is, yes, it’s serious, but we don’t immediately panic.”
Doel said that history is somewhat helpful in preventing future problems, but no analogy is perfect. “History often doesn’t repeat, exactly, but it often rhymes,” he said.
For example, early in the space shuttle’s 30-year history, launches often took place every few weeks. This was in large part because, as the nonprofit Planetary Society points out, “the U.S. adhered to a shuttle-only launch policy for all space missions.” While the shuttle was an incredible vehicle, early hopes that it would serve as a rapid-reuse “space truck” were quickly dashed, especially by the Challenger and Columbia accidents.
“The shuttle’s legacy is complex: It never lived up to its promise of enabling fast, affordable space travel,” the Planetary Society wrote. “Nevertheless, the shuttles made impressive scientific, technological and cultural achievements. The most well-traveled shuttle, Discovery, flew 39 times — a record that will stand for years to come.”