Originally posted to 13.7 Cosmos & Culture on 2/10/2016

It is a sad curiosity that the word "disaster" comes from star (aster), as in "an ill-starred event," owing its etymological roots to astrology.

Jan. 28 marked the 30th anniversary of the Challenger disaster, one of the worst accidents in the history of the American space program. A nation watched, horrified, as the Challenger space shuttle blew up shortly after takeoff, killing all seven crew members. It was the first disaster in which U.S. astronauts died in flight. Among them was Christa McAuliffe, a high school teacher from Concord, N.H., mother of two, who would have been the first ordinary citizen in space.

There is now a Christa McAuliffe Planetarium in Concord, part of the McAuliffe-Shepard Discovery Center. Its promotion motto is: "The sky is no limit; it's just the beginning."

After the disaster, there was a major effort — a witch hunt — trying to figure out what had happened. The culprit, it turned out, was an O ring that failed to seal a rocket booster, allowing hot gas from the booster to hit the external fuel tank. Richard Feynman, one of the all-time physics greats, demonstrated to a dumbfounded White House panel that the O rings lose resilience at low temperatures. (Feynman dropped one in a cup of ice-cold water and showed that it stiffened up.)

In the case of the Challenger, the launch was at uncommonly low temperatures (it was in the low 20s the morning of the launch), and the O ring must have cracked under pressure, literally. As Feynman noted in an interview, NASA's administrators' mistake was not taking notice of similar malfunctions before, such as leakages around the O rings in previous missions and tests. The disaster could have been easily avoided, he concluded.

The last shuttle flight was in July 2011, when Atlantis flew to the International Space Station with no accidents. Since then, the manned space program has taken a sharp turn, as NASA decided to first use Russian spaceships, and now private companies (so far, Boeing and SpaceX) will soon take astronauts to space.

(Left) Bob Ebeling in his home in Brigham City, Utah. (Right) The Challenger lifts off on Jan. 28, 1986, from a launchpad at Kennedy Space Center, 73 seconds before an explosion killed its crew of seven.

There is no stopping human exploration of space. We are bound to outer shores as we were once bound to shores on this planet. Accidents will happen along the way, as shipwrecks did — and still do — happen. Let us learn our lessons, though, so that every effort is made to spare as many lives as possible in the years ahead.