Tell me please, what was the root cause of Space Shuttle Challenger disaster.

The root cause of the Space Shuttle Challenger disaster was a failure in the O-rings that sealed the joints in the shuttle's solid rocket boosters. The O-rings were not designed to cope with the cold temperatures on the day of the launch, and so they became brittle and failed, allowing hot exhaust gases to escape and ignite the external fuel tank.

Why was Challenger launched in cold weather?

The Challenger launch was scheduled for cold weather conditions because of the payload it was carrying. The payload was a satellite that was sensitive to temperature changes, and so the launch was scheduled in order to ensure that the satellite would be in the ideal temperature range when it was deployed. NASA engineers were aware of the O-ring issue, but did not think the cold temperatures would cause a problem.

What was the payload? TDRS?

Yes, the payload was the Tracking and Data Relay Satellite (TDRS-B). This satellite was an important part of NASA's communication system, and was designed to provide real-time data and voice communication to spacecraft in Earth orbit.

Did the crew survive the explosion?

No, the crew of seven were killed in the explosion. The exact cause of their deaths is still unknown, but it is thought that they were killed instantly by the force of the explosion or quickly asphyxiated by the lack of oxygen in the cabin.

Did the crew have spacesuits and helmets?

No, the crew were not wearing spacesuits or helmets. They were wearing light flight suits, which were designed to provide protection from the cold temperatures of space, but not the intense heat and pressure of an exploding rocket. 
Did the astronats have their own air supplies?

No, the astronauts did not have their own air supplies. The cabin of the Space Shuttle was pressurized and the astronauts were relying on the air in the cabin to breathe during the launch.

Thank you.

One more question about space shuttles.

What is the purpose of the Space Shuttle?

The purpose of the Space Shuttle is to provide a reusable spacecraft for crewed and unmanned missions into space. It is designed to be able to launch, travel to and from orbit, and land safely on Earth. The Space Shuttle has been used to deploy satellites, conduct scientific experiments, and even build the International Space Station.

What was the root cause of SpaCE sHUTTLE cOLUMBIA DISASTER?

The root cause of the Space Shuttle Columbia disaster was a hole in the leading edge of the left wing, caused by a piece of foam that had broken off from the external fuel tank during launch. The heat of re-entry into the Earth's atmosphere caused the hole to expand, leading to the disintegration of the Shuttle and the death of all seven crew members.
Were there any chance to rescue the crew?

Unfortunately, no. By the time the damage to the Shuttle became apparent, it was already too late to rescue the crew. The Shuttle was travelling too fast and too far away for any rescue attempt to be successful.

Why the piece of foam broke off from the external tank?

The piece of foam broke off from the external tank due to a manufacturing defect. The foam was not properly bonded to the external tank and so it broke off during launch and struck the leading edge of the left wing. This impact caused a hole in the wing, which eventually led to the disaster.
Why the piece of foam was not properly bonded to external tank?

The piece of foam was not properly bonded to the external tank because of a design flaw. The designers of the external tank had not taken into account the extreme conditions that the tank would experience during launch, and so the foam was not able to withstand the forces it was subjected to. 
What kind of changes in design of external tank were made after Columbia disaster?

After the Columbia disaster, the design of the external tank was changed to make it more robust. The foam insulation was changed to a new type of foam that was more resistant to impact, and the tank was also strengthened in other areas. Additionally, the external tank was designed to be more easily inspected for damage after launch.
Why a very tough carbon-carbon leading edge was damaged by olny a piece of foam?

The carbon-carbon leading edge of the Space Shuttle's wing is designed to be tough and resistant to the extreme heat of re-entry into the Earth's atmosphere. However, the impact of the piece of foam caused a hole in the leading edge, which allowed hot gases to enter the wing and eventually cause the Shuttle to break apart.

When space shutle Columbia began to disintegrate?

Space Shuttle Columbia began to disintegrate about 16 minutes before it was due to land. The Shuttle had already entered the Earth's atmosphere and was travelling at a high speed when the damage from the foam strike began to cause the Shuttle to break apart. By the time the crew were aware of the problem, it was too late for them to take any evasive action.

What was the cause of death of the crew?

The exact cause of death of the crew of the Space Shuttle Columbia is unknown, but it is thought that they were killed instantly by the force of the explosion or quickly asphyxiated by the lack of oxygen in the cabin.