January 28, 1986 was unusually cold in Florida. NASA engineers, scientists, and astronauts were preparing for the launch of the space shuttle Challenger. Hundreds of thousands of people across the world tuned into their televisions, giving a still up-and-coming 24-hour news network called CNN a larger viewing audience than it was used to. In addition to the miracle of science that is space exploration, the Challenger launch was also a human interest story because of one of the astronauts on board: Christa McAuliffe.
Christa McAuliffe was a 37-year-old high school teacher from New Hampshire who had been selected to join the Challenger crew from among 11,000 applicants who entered President Ronald Reagan’s Teacher in Space Program. The program was designed to send a regular person into space, but President Reagan wanted the first regular person in space to be an educator who could communicate with their classes while in on the shuttle. This was, in part, a marketing ploy to increase public interest in the space shuttle program, which was relatively unknown and at risk of being shut down if no additional funding could be found.
In the lead up to the launch, McAuliffe went on a media tour, appearing on many news and entertainment shows from CBS Morning News to The Tonight Show. When she finally boarded the Challenger on the morning of January 28, 1986, she drew a huge television audience, including thousands of schoolchildren across the country.
Cape Canaveral, Florida doesn’t get too cold all that often. In fact, the average low in January is around 56°F. The evening of January 27 and the morning of January 28, 1986 was an exception. Temperatures dropped to 18° overnight, gradually rising to 26° at the scheduled launch time of 9:38 a.m. NASA scientists were somewhat concerned with some O-rings on the solid rocket boosters (SRB) because those O-rings had not been tested to hold in launch temperatures below 53°, and there was concern that the sudden change in temperature caused by the heat of liftoff could compromise the O-rings and prevent them from sealing properly. After a conference call in which the matter of the O-rings was debated, the launch was rescheduled for 11:38 a.m. and NASA authorities presumably believed the O-rings would hold even though the launch time temperature was only going to be 36°.
At 11:38 a.m., Challenger lifted off from Cape Canaveral. Seventy-two seconds after launch, O-ring failure caused one SRB to disconnect from the shuttle, causing sideways acceleration that scientists believe the crew felt. One second later, Challenger began to break up. The fuselage where the crew were was separate from the rest of the shuttle, SRBs, and debris and was moving at astonishing speed. Within ten seconds of breakup, the crew were in a freefall from 65,000 feet. Amazingly, neither the explosion nor the freefall likely caused major physical damage to the crew, though if the cabin lost pressure they would have lost consciousness.
A review of the wreckage, recovered from the Atlantic Ocean, showed that attempts had been made by the crew to restore power to the fuselage, indicating that at least some of the crew were alive in the immediate aftermath of the breakup. Analysts were unable to determine whether the crew was alive at the time the fuselage made contact with the ocean. Impact occurred at over 200 miles per hour about two minutes and forty-five second after breakup. The force of impact was over 200 g, enough to rip the fuselage apart and kill any crew who remained living.
Recovery efforts continued for months after the launch as NASA tried to find as much of the debris as possible so that a cause of the disaster could be determined. Ultimately, a presidential commission determined that the O-rings on the right SRB had failed due to the cold launch temperature. At the time, the space shuttles were not designed with emergency escape mechanisms during powered flight, so the crew did not have a chance to escape the cockpit if they were conscious.
The entire crew died, including Christa McAuliffe, who has become the face of the Challenger disaster and the resulting tragedy. However, there were a total of seven crew members:
Dick Scobee, commander;
Michael Smith, pilot;
Ronald McNair, mission specialist;
Ellison Onizuka, mission specialist;
Judith Resnik, mission specialist;
Greg Jarvis, payload specialist; and
Christa McAuliffe, payload specialist.
Dick Scobee was the oldest member of the crew, aged 46. Ronald McNair was the youngest at 35.
Changes to procedures in the aftermath of Challenger included adding emergency escape methods during powered flight, pressurized suits for the crew during ascent and reentry, and the Teacher in Space program was canceled.
Engineers now know that the O-rings stood no chance of holding in a launch in such cold temperatures, and the Challenger disaster continues to serve as a lesson in the importance of detailed study and strategy for space exploration. We remember the brave members of the Challenger crew, and we continue to hope that no such disasters befall any future space exploration.