On the morning of 28 January 1986, the Space Shuttle Challenger exploded just 73 seconds into its flight, leading to the deaths of its seven crew members. Travelling at nearly 2,000mph at a height of ten miles, the Space Challenger was enveloped in a red, orange and white fireball as thousands of tons of liquid hydrogen and oxygen fuel exploded. The US subsequently put all space flights on hold for 32 months.

According to reports, a ruptured O-ring (mechanical gasket in the shape of a circle) located in the right solid rocket booster caused the explosion after the shuttle launched from the Kennedy Space Center.

Space Challenger 30th Anniversary
The Space Shuttle Challenger crew takes a break during countdown training at NASA's Kennedy Space Center on 9 January, 1986. From left: Teacher-in-Space payload specialist Sharon Christa McAuliffe; payload specialist Gregory Jarvis; and astronauts Judith A. Resnik, mission specialist; Francis R. (Dick) Scobee, mission commander; Ronald E. McNair, mission specialist; Mike J. Smith, pilot; and Ellison S. Onizuka, mission specialist.NASA
Space Challenger 30th Anniversary
US space shuttle Challenger lifts off 28 January 1986 from a launch pad at Kennedy Space Center, 73 seconds before its explosionGetty Images
Space Challenger 30th Anniversary
Ice on the launch pad of the Space Shuttle Challenger is shown in an inspection picture taken the morning of the launch on 28 January, 1986. The launch went ahead despite the cold conditions, which were later cited as a possible cause of the failure of a part that caused the explosion of the shuttle 73 seconds after takeoffReuters

After the explosion, engineers argued that the overnight temperatures of -8 °C on the evening prior to the launch were below their redline of 4°C. Ice had accumulated on the inside of the launch pad, raising concerns that the ice could damage the shuttle upon lift-off. The temperature on the day of the launch was also far lower than previous shuttle launches and despite the Ice Team working hard through the night to remove the ice, the engineers still expressed deep concern.

In July 1986, six months after the tragedy, a report was released on the deaths of the crew but was inconclusive, due to a number of factors that remained uncertain about the explosion. The report concluded that the cause of death for all seven crew members could not be determined. Those on board included five astronauts, Judith A. Resnik, Francis R. Scobee, Ronald E. McNair, Mike J. Smith and Ellison S. Onizuka along with payload specialists Sharon Christa McAuliffe and Gregory Jarvis.

Thirty years on a new generation of spaceships continues to build on changes made after NASA's fatal accident.

Space Challenger 30th Anniversary
The Space Shuttle Challenger lifts off January 28, 1986 from Kennedy Space Center, FloridaGetty Images
Space Challenger 30th Anniversary
The Space shuttle Challenger lifts off on an apparently flawless launch 28 January 1986 over Space Kennedy CenterBob Pearson/ Getty Images
Space Challenger 30th Anniversary
The solid fuel rocket booster of the space shuttle Challenger starting to explode over Kennedy Space Center on January 28, 1986Bob Pearson/ Getty Images
Space Challenger 30th Anniversary
The booster rockets from the Space Shuttle Challenger fly off after the shuttle exploded after lift off January 28, 1986 from Kennedy Space Center, FloridaNASA/ Getty Images
Space Challenger 30th Anniversary
The Space Shuttle Challenger explodes seconds after takeoff from the Kennedy Space Center at Cape Canaveral, Florida, 28 January 1986NASA/ Reuters
Space Challenger 30th Anniversary
A solid fuel rocket booster disappears behind the contrail of the explosion of the space shuttle Challenger 28 January 1986 over Kennedy Space Center as debris from the orbiter begins to fall to earthBob Pearson/ Getty Images
Space Challenger 30th Anniversary
A solid fuel rocket booster disappears behind the contrail of the explosion of the space shuttle Challenger 28 January 1986 over Kennedy Space Center as debris from the orbiter begins to fall to earth. The US space shuttle exploded seconds after lift-off, killing it crew of sevenGetty Images
Space Challenger 30th Anniversary
With the help of the U.S. Coast Guard and the U.S. Navy, search and recovery teams retrieve pieces of the Space Shuttle Challenger (STS-51-L) from the Atlantic Ocean near the Kennedy Space Center. Vessels brought the debris to the Trident Basin at Cape Canaveral Air Force Station, where they waited to be shipped to KSC for investigation on January 301,1986Reuters
Space Challenger 30th Anniversary
Pieces of the Space Shuttle Challenger are arranged in a hangar after being salvaged from the Atlantic Ocean where they were scattered, on January 28, 1986 when the spacecraft exploded, putting all space flights on hold for 32 monthsGetty Images
Space Challenger 30th Anniversary
Space Shuttle Challenger crew members gather for an official portrait November 11, 1985. From top left: Mission Specialist Ellison S. Onizuka, Teacher-in-Space participant Sharon Christa McAuliffe, Payload Specialist Greg Jarvis and mission specialist Judy Resnick. (Front, L-R) Pilot Mike Smith, commander Dick Scobee and mission specialist Ron McNair.Getty Images