Challenger Space Shuttle

The space shuttle Challenger (NASA designation: OV-099) was the second orbiter in the space shuttle program to enter service. It was built by the Rockwell International company. Its maiden flight took place on April 4, 1983, and it completed nine missions before disintegrating on its tenth mission, on January 28, 1986, killing its seven crew at age 73. seconds after launch. The Challenger was succeeded by the space shuttle Endeavour, which first flew in 1992, six years after the accident.

History

The Challenger shooting during your STS-8 mission.

The name Challenger comes from HMS Challenger, a British sloop that undertook a global marine research expedition in the year 1870.

Construction

The Challenger was built from the STA-099 structure, originally used in structural testing. STA-099 was not designed for flight, but NASA felt that recycling would be less expensive than retrofitting the test shuttle Enterprise (OV-101) for space flight, as originally planned.

The Challenger, like the orbiters built after it, had fewer tiles in its thermal protection system than the Columbia. Most of the tiles on the cargo doors, the upper surfaces of the wings, and the rear of the fuselage were replaced with white nomex insulation from DuPont. This modification allowed the shuttle to carry 1,100kg more payload than the Columbia. The Challenger was also the first orbiter to carry a system of HUD displays similar to those used on modern military and civilian aircraft. This system eliminated the need to look at the instrument panel during descent and allowed the crew to concentrate more on the flight.

Flights

After its initial flight, Challenger became the workhorse of NASA's shuttle fleet, flying more missions per year than Columbia. In the years 1983 and 1984, the Challenger flew 85% of the missions of the STS program. Even when the Discovery and Atlantis orbiters joined the fleet, Challenger continued to be used for heavy duty up to three times per year from 1983 to 1985.

The Challenger, along with the Discovery, was modified at the John F. Kennedy Space Center to accommodate the upper stage of the Centaur rocket in its cargo bay. If the STS-51-L mission had been successful, the next shuttle mission would have been the deployment of the Ulysses probe with Centaur, to study the polar regions of the Sun.

The shuttle Challenger marked several milestones in spaceflight, including the first American woman, the first African-American, and the first autonomous walk in space, three Spacelab missions, and the first night takeoff and landing of a space shuttle. However, the Challenger was also the first shuttle to be destroyed in a mission accident.

Table of missions

Tribute and Mission Badges

NASA Tribute by Space Shuttle Challenger
Mission badge for Challenger mission flights
STS-6	STS-7	STS-8	STS-41-B	STS-41-C	STS-41-G	STS-51-B	STS-51-F
STS-61-A	STS-51-L	STS-61-F♪

* Mission canceled after loss of Challenger on STS-51-L.

Challenger accident

Disintegration of Challenger

Challenger disintegrated 73 seconds after the launch of STS-51-L, the orbiter's tenth mission, on January 28, 1986, when an O-ring on its rocket Right hand drive (SRB) failed in its sealing function.

Accident sequence

The sealing rings failed mainly due to repeated overcompression during assembly and further aggravated by low temperatures. This anomaly was noticed by Morton Thiokol engineers, the manufacturers of the impeller parts, NASA was warned, but under pressure from NASA itself, Morton Thiokol engineers relented and authorized takeoff.

Rocket fuel was enriched with aluminum shavings that gave it greater thrust; probably the aluminum slag momentarily sealed the crack in the joint, delaying the catastrophe. At the time of takeoff, the right thruster lets out black smoke nine times in a period of 2.6 seconds, and stops when the craft boosts. On ignition the shuttle pitches 1 meter from side to side before propelling off; with every pitch black smoke escapes.

At 58 seconds, the shuttle passed moment Q, also known as maximum dynamic pressure (instability), as it passed through a strong wind current; this reopened the board. It also caused a column of fire to escape from the SRB and burn the external fuel tank (ET). Liquid hydrogen from the spilled external tank began to ignite, severing the clamps holding the SRB. The SRB swayed and struck the Challenger's right wing. This caused the entire assembly to jerk around, exposing the shuttle to uncontrolled aerodynamic forces.

The shuttle was then engulfed in a gigantic fireball 73 seconds after takeoff, disintegrating almost entirely, the cabin emerging from the conflagration intact.

The seven crew members died when the ship's cabin impacted the ocean, after a long fall of almost three minutes. The final circumstances of their death are unknown; The accident investigation commission determined as "unlikely" the fact that any of them were conscious at the time of impact, although evidence later came to light that at least four of the crew members were able to activate their auxiliary systems. oxygen supply, and who tried to help each other.

The cabin was the only section of the ship that managed to survive the terrible destruction of the explosion, but it could not withstand the final impact against the ocean, disintegrating along with its occupants. The cabin module fell from a height of 15,240 meters, thus producing the fatal outcome.

Further Research

NASA had estimated the odds of a catastrophic accident during launch (the most dangerous moment of space flight) at a ratio of 1 in 438.

This accident, the most shocking in the Space Shuttle Program, seriously damaged NASA's reputation as a space agency, and the civilian participation proposal, promulgated by Ronald Reagan and finalized with elementary school teacher Christa McAuliffe, was thrown out of favor. ground all administrative and security structures. NASA temporarily suspended its space flights until 1988.

A subsequent investigation concluded a series of errors committed:

• Wind currents eliminated the fuel slag (aluminium) that sealed the right tank hole and caused the loss of fuel.
• The low quality application of SBR seals (styrene-butadiene).
• Unusually low temperatures.
• Repeated overcompression of the toric joints during assembly.
• The lack of quality control inspection by Morton Thiokol.
• The lack of verification systems by NASA.
• Underestimation of Tyco's engineers about the possibility of accident.
• Lack of fierce will of the Tyco Review Board to stop taking off.
• Lack of an emergency abortion system takes off when decompressions or anomalies occur.
• Lack of an emergency plan when the shuttle is in danger at the time of taking off.

All these factors were linked one by one and were the cause of the disaster.

Hypothesis:

• For sabotage, although she was ruled out by NASA.
• Weather conditions not suitable for launch.
• High speed.
• For missing pieces.

Astronauts did not have parachutes or ejection equipment; They also did not have specific training for a case like this, circumstances that led to strong criticism of NASA.