Pad 39B witnessed America’s most tragic space disaster on live television

NASA’s Challenger Launch Site at Pad 39B

At 11:39 AM on January 28, 1986, Space Shuttle Challenger broke apart 73 seconds after launch from Kennedy Space Center’s Pad 39B.

This was mission STS-51L, the 25th Space Shuttle flight, and Challenger’s 10th trip to space though it only ended in tragedy.

The explosion killed all seven crew members, including teacher Christa McAuliffe, who was set to become the first civilian in space.

Engineers had warned about O-ring failures in cold weather, but the launch went ahead anyway. Here’s the full scoop.

Record Cold Temperatures Hit The Launch Pad

An unusual cold front swept through Florida the night before launch.

The temperature dropped to just 36 degrees Fahrenheit. Thick ice formed over parts of the shuttle’s external fuel tank and launch tower.

Engineers had warned about O-ring failures in cold weather, but NASA managers decided to go ahead with the launch anyway.

Engineers Warned About O-Ring Failure Risk

Engineers from Morton Thiokol, the company that built the rocket boosters, warned about launching in cold weather.

Tests showed the O-rings became stiff in temperatures below 50 degrees which influenced the sealing mechanism between rocket segments.

The night before launch, Morton Thiokol engineers urged NASA to wait for warmer weather but officials rejected this advice.

The Crew Boarded Despite Multiple Delays

Originally set for July 1985, NASA pushed it to January 1986, then delayed it again to January 28 owing to bad weather.

Even technical problems caused these delays as the crew awaited instructions through the many postponements.

The seven astronauts boarded Challenger on that cold January morning. The launch was set for 11:38 am. Eastern Time despite the unusual cold.

Liftoff From Launch Pad 39B

Challenger lifted off right on schedule at 11:38 a.m. The main engines and solid rocket boosters fired, pushing the shuttle upward.

This was Pad 39B’s first shuttle launch. NASA had not used this pad since 1975 when it launched the Apollo-Soyuz mission.

This launch day was special at Kennedy Space Center. Space Shuttle Columbia sat on the nearby Pad 39A while Challenger took off from Pad 39B.

The First Signs Of Catastrophic Failure

Right after liftoff, puffs of dark smoke escaped from the right rocket booster. Cameras caught nine smoke puffs during the first three seconds.

The smoke came from a leaking joint between booster segments. The cold had made the rubber O-rings too stiff to seal properly.

The leak temporarily sealed itself when melted aluminum particles plugged the gap. This gave a false sign that the problem had fixed itself.

Seventy-Three Seconds After Launch

Mission Control told Commander Scobee, “Challenger, go with throttle up.” The crew increased power as planned.

Seconds later, at 73 seconds into flight, Challenger broke apart at 46,000 feet above the Atlantic Ocean, and the crew had no time.

Hot gases from the failed seal had burned through to the fuel tank. Once the tank ruptured, powerful air forces tore the shuttle apart.

Millions Watched The Tragedy Unfold Live

TV networks covered the launch extensively because of Christa McAuliffe, the civilian astronaut. Her selection had created huge public interest in this mission.

About 17 percent of all Americans watched the launch live on TV. Schools across the country set up televisions to witness the historic moment.

As the shuttle broke apart, NASA’s commentator said, “Flight controllers here looking very carefully at the situation. Obviously a major malfunction.”

The Immediate Aftermath At The Launch Site

Navy and Coast Guard ships rushed to search for crew and spacecraft debris, recovering whatever they could find in the Atlantic.

Search teams scoured 480 square miles of ocean floor for months.

President Reagan canceled his planned State of the Union speech that night. Instead, he spoke to the nation about the disaster.

NASA stopped all shuttle flights until they could understand what went wrong.

Technical Cause Of The Explosion Determined

President Reagan formed a special commission to investigate the accident. Led by William Rogers, it became known as the Rogers Commission.

It was revealed an O-ring seal in the right rocket booster had failed. The cold temperatures had made the rubber too stiff as predicted.

This allowed hot gases to escape and damage the external fuel tank. The commission also blamed NASA’s organizational culture.

NPR coverage indicates Allan McDonald’s role in voicing objections to the Challenger launch, later revealing the truth behind the disaster.

Launch Pad 39B After The Disaster

NASA redesigned the rocket boosters with extra O-rings and added heaters to keep them warm. The space agency spent over two years fixing problems.

After 32 months without shuttle flights, Launch Pad 39B hosted the return-to-flight mission with Space Shuttle Discovery.

The launch on September 29, 1988 was a success. Pad 39B went on to support 53 more shuttle launches between 1988 and 2006.

The first seven missions after returning to flight all used this pad.

Visiting Kennedy Space Center Visitor Complex, Florida

You can explore the Kennedy Space Center Visitor Complex in Merritt Island, Florida to learn about the Challenger disaster.

The permanent “Forever Remembered” memorial exhibit displays an actual piece of Challenger’s recovered fuselage.

The Explore Tour passes Launch Complex 39B, Challenger’s lift-off site. While you can’t walk the pad, the tour offers great views of the historic launch area.

The Atlantis exhibit which tributes both Challenger and Columbia crews. The KSC bus tour further talks about the disaster’s impact on NASA’s safety protocols.

Visit the Apollo/Saturn V Center to see how Launch Pad 39B evolved from Saturn rocket launches to the Space Shuttle program.

Read More on WhenInYourState.com:

• Florida’s Launch Pad 39A and the 9 Minutes That Changed the World in 1969
• The Historic Florida Ballpark Where Jackie Robinson Broke Baseball’s Color Barrier
• The Beautiful Florida Island Made Famous by a Fake Pirate