Explorers scoured the Atlantic Ocean for World War II artifacts lost at sea, but stumbled upon something else — a 20-foot-long piece of debris from the Space Shuttle Challenger, which was destroyed shortly after liftoff in 1986.   

  The History Channel and NASA revealed Thursday that the Challenger segment was discovered off the east coast of Florida during the filming of a new series called “The Bermuda Triangle: Into Cursed Waters.”  The series is set to premiere this month on the History Channel.   

  Challenger disintegrated after launch on January 28, 1986, killing all seven crew members, including a teacher who was to become the first civilian in space.  Television viewers, particularly students at schools in the US, watched in horror as a live broadcast of the explosion occurred that morning.   

  “NASA is currently considering what additional actions it can take regarding the artifact that will properly honor the legacy of the fallen Challenger astronauts and the families who loved them,” the space agency said in a news release.   

  Mike Barnette, an underwater explorer who led the crew that found the shuttle artifact, remembers watching the tragedy on television in his high school classroom.  He called it “unrealistic” to realize his team had found a fragment of the spacecraft – the first debris to be discovered since pieces of the shuttle washed ashore in 1996.   

  “I can almost smell the smells of that day,” Barnette told CNN in a phone interview Thursday, referring to the day Challenger exploded.  “It was so burned into my brain.”   

  Barnett and his team of researchers set out in March to investigate suspected wreck sites in the Bermuda Triangle, an area of ​​the North Atlantic Ocean said to be the site of dozens of shipwrecks and plane crashes.  The team also targeted an area outside the triangle, just off Florida’s Space Coast, where NASA has launched rockets since its inception.   

  The team was searching for a World War II-era rescue plane that mysteriously disappeared in December 1945, but a more modern object partially covered by sand on the sea floor sparked interest and further investigation by the dive team, according to History Channel.   

  During the first dive, Barnette said a storm made the water so murky it was like swimming in Guinness beer.  “We had terrible visibility,” he said.   

  Divers made a second excursion in May and finally captured clear footage of the wreckage.  They brought evidence of their discovery to retired NASA astronaut Bruce Melnick, a longtime friend of Barnett’s, who immediately suggested it could be debris from the Challenger disaster.   

  Distinctive square tiles from Challenger nudged the explorers, suggesting they had uncovered a large chunk of the orbiter’s belly.  The underbelly was coated with thousands of silicon tiles protecting the shuttle from heat as it re-entered Earth’s atmosphere from space.   

  The team submitted its findings to NASA in August, and the space agency recently confirmed the origin of the debris after reviewing material from the dive, according to a news release.   

  The final Challenger mission was to carry seven people into space – NASA astronauts Francis “Dick” Scobee, Michael Smith, Ronald McNair, Ellison Onizuka, Judith Resnik and Gregory Jarvis as well as Christa McAuliffe, a New Hampshire teacher who was to become the first civilian space shuttle passenger as part of a new NASA program.   

  But 73 seconds after liftoff from the Florida launch site, the Challenger exploded, killing everyone on board.  A NASA investigation later revealed that a rubber “O-ring” seal on one of Challenger’s solid rocket boosters had failed because it was exposed to unusually cold temperatures while the shuttle sat on the launch pad.  It caused a leak of highly explosive gases, which eventually led to the devastating explosion.   

  “While it has been nearly 37 years since seven daring and brave explorers lost their lives aboard the Challenger, this tragedy will forever be etched in our nation’s collective memory.  For millions around the world, including myself, January 28, 1986, still feels like yesterday,” said NASA Administrator Bill Nelson.   

  “This discovery gives us an opportunity to pause once again, to highlight the legacies of the seven pioneers we lost, and to reflect on how this tragedy has changed us.  At NASA, the core value of safety is — and must forever remain — our top priority, especially as our missions explore more of the Universe than ever before.”   

  The six-part series “The Bermuda Triangle: Into Cursed Waters” premieres at 10:00 PM ET on November 22 on the History Channel.