Challenger Explosion | Universe Today

Written by Jerry Coffey

The space shuttle Challenger explosion occurred 73 seconds after the mission's launch and caused the death of all seven crew members. The Challenger disintegrated off the coast of Florida, above the ocean, at 11:39 a.m. EST. The Challenger explosion was directly linked to the failure of an o-ring to seal in the right solid rocket booster. The exact timing of the death of the crew is unknown, but several crew members are known to have survived the initial breakup of the spacecraft. Since the shuttle had no escape system, the astronauts did not survive the impact of the crew compartment with the ocean surface. The disaster led to a 32-month halt of the shuttle program

The Challenger explosion began after an o-ring seal in its right solid rocket booster failed at liftoff. The o-ring failure caused a breach in the SRB joint it sealed, allowing pressurized hot gas from the solid rocket motor to reach the outside and encroach upon the adjacent SRB attachment hardware and external fuel tank. This led to the separation of the right-hand SRB's aft attachment and the structural failure of the external tank. Aerodynamic forces acted quickly to break the orbiter apart. In response to the Challenger explosion the Rogers Commission was formed by the Reagan administration.

The phrase "Challenger explosion" is misleading. The shuttle nor any of its external tanks ever exploded. The spacecraft simply disintegrated fro wind sheer and other aerodynamic forces since it was just past "Max Q"(maximum aerodynamic pressure). When the external tank disintegrated, the fuel and oxidizer stored within it were released, producing the appearance of a massive fireball. The visible cloud was primarily composed of vapor and gases resulting from the release of the shuttle's liquid oxygen and liquid hydrogen propellant.

The investigation of the Challenger explosion by the Rogers Commission led to several conclusions: first that NASA's organizational culture and decision-making processes had been a key contributing factor to the accident. NASA managers had known that the design of the SRBs contained a potentially catastrophic flaw in the o-rings since 1977, but they failed to address it properly. They also disregarded warnings from engineers about the dangers of launching posed by the cold temperatures of that morning and had failed to adequately report these technical concerns to their superiors. The Rogers Commission offered NASA nine recommendations that were to be implemented before shuttle flights resumed. These recommendations can be found in the links below.

There are two good articles about the Challenger explosion, one here and the other here. Here on Universe Today we have a great article about the Challenger's most famous crew member, Christa McAuliffe. Since the Challenger explosion originated in the solid rocket booster, I thought a good episode from Astronomy Cast about rockets would be a nice piece to research.

Filed under: Astronomy