1986 weather

The inside story of the space shuttle Challenger crash.

Five years after the explosion of the space shuttle Challenger/KLOC-0, two senior spacecraft design engineers finally broke the silence and uncovered the cause and effect of the explosion.

"Challenger" exploded instantly during takeoff.

The American space shuttle Challenger burst into flames 73 seconds after launch from Cape Canaveral Space Base. It has been 15 years, but the audience who watched the live TV broadcast must remember the shocking fireball vividly. Two people who were watching live TV in Utah at that time were not surprised by the result. Both are senior engineers of Morton-Theokol, which designs and manufactures solid fuel rocket boosters for the space shuttle. One is Roger Boysjoli, and the other is his immediate boss, Bob Eberlin.

A few minutes before the Challenger launch, Boyce Jolly paced up and down anxiously outside the conference room of Theokol Company. Eberling wants Boyce Jolly to go to the conference room to watch the live broadcast of the space shuttle launch. At first, Boyce Jolly told Eberlin, "No, I don't want to see the launch. I don't want to see the launch fail. "

The night before, Boyce Jolly and Ebelin spent six hours in a video conference, urging NASA to postpone the launch of Challenger, because before that, they were both told that the temperature in Florida had dropped below 0℃. They know that such conditions will have a great impact on the performance of rocket boosters! However, the top management of Theokol Company gave them a blow, and the company proposed a "launch" proposal to NASA!

After the countdown began, the two men held each other tightly. To their delight, the challenger left the launch pad smoothly and took off! Boyce Jolly turned to Eberlin: "We just dodged a bullet!" "Because according to their analysis, Challenger will explode on the platform. However, just as both of them wanted to take a long breath, the TV screen in front of them suddenly filled with smoke in the 73rd second after Challenger took off, and their hearts almost stopped.

1986 In July, after accepting the hearing of the presidential committee on the challenger disaster, Boyce Jolly left the Theokol proving ground deep in the Wasatch Mountains in northern Utah.

The engineer was shocked when he learned of the launch danger?

Boyce Jolly shot the managers of Theokol at the hearing of the Presidential Committee. His practice was criticized by the company, which thought that he should not disclose relevant documents to the president's Committee, and his colleagues even held a grudge against him because he broke their "golden rice bowl".

Today, 0/5 years after the Challenger explosion/KLOC-,Theokol's proving ground is still closed to outsiders, but the company's rocket park is open to tourists. There are more than 20 rocket engines of various models in the park. A 1.26-foot solid fuel engine is put together with other engines, just like a group of people. Most of the power for the space shuttle to enter orbit is provided by this engine.

After being filled with millions of pounds of solid booster fuel, each rocket booster will be sent to Cape Canaveral launch base. Because there is no railway to transport objects with the length of 1.26 feet, Theokol Company has to transport the rocket into several parts and assemble it at the launch site.

Boyce Jolly said: "These steel rings look very strong, but after they are ignited, each part will be' blown' like a balloon due to great pressure. In this way, it is necessary to use elastic bands at the joints of various parts to prevent hot air from running out of the rocket. " This work is completed by two rubber belts called "O-rings", which can expand with the steel rings to bridge the gap. If these two rubber belts are separated from the steel ring for even 0.2 seconds, the fuel of the booster will leak and the solid rocket booster will explode.

It was very cold the day Challenger was launched. When the temperature drops, these "circles" become very hard, and it is more difficult to expand and contract. The expansion and contraction speed of hard "O-ring" is slow, and the sealing effect is greatly reduced. Although it may only be a few tenths of a second, it is enough to turn a successful launch into a disaster.

The tragedy of "Challenger" is that Boyce Jolly questioned "Circle 0" six months before the launch, because he personally went to Florida a year ago to inspect the rocket used in the last launch. To his surprise, the first layer of "circle 0" failed and the hot air escaped. Fortunately, the second floor "circle 0" blocked the hot air. Boyce Jolly still retains the "Circle 0" photo taken at that time, and the lubricant that should have been honey-colored was smoked black. Many places in the "circle 0" on the first floor are missing. Obviously, they are burnt. He said: "When I saw all this, my heart was like a cotton ball. That launch, the space shuttle did not explode, it was a miracle! "

Boyce Jolly's analysis caught the attention of NASA and put "circle 0" on the list that needs careful inspection. Theokol also set up a "task force" to solve this problem. However, due to the shortage of equipment and manpower, the progress of the project is slow. As a member of the "task force", Boyce Jolly sent a memo to the vice president of Theokol Company, requesting a comprehensive and stricter test of "Circle 0". He wrote in the memo: "To be honest, I am really worried that if we don't take measures quickly, not only will the launch fail, but even the launch platform will be burned, and the most serious consequence will be catastrophic human-machine destruction!"

Challenger was originally scheduled to launch on October 25th, 65438/KLOC-0, but it was postponed twice due to bad weather. When the astronauts took their positions and prepared for the final countdown, the staff suddenly found that they could not move the handle on the shuttle door! After five hours of tossing, I finally closed the hatch with a saw.

Please your employer and get into big trouble?

That afternoon, the temperature in Cape Canaveral plummeted, and the launch team needed to listen to experts' opinions. At about 6 pm, I called Utah and asked the experts in Theokol if they had any doubts about launching rockets at minus 5℃. The expert's answer is "yes".

Then, the launch site called the rocket expert of NASA at Marshall Space Flight Center in Alabama. Judson lovegood from the Space Shuttle Project Office answered the phone. That night, the experts at Marshall Center really listened carefully to Boyce Jolly and his colleagues' analysis of the delayed launch, but they felt that what they heard was something emotional and too little rational. Although Boyce Jolly also put forward some data, none of them are conclusive.

Theokol's bottom line is that it doesn't want to fly based on data outside its database, that is, it is absolutely impossible to fly when the temperature is below-12℃, which is the lowest temperature recorded at the time of launch so far. Boyce Jolly also said that the "circle 0" he checked a year ago was destroyed, mainly because the temperature was too low.

After nearly five hours of discussion, NASA finally said that it would not launch forcibly if it did not listen to the advice of the rocket designer. Just then, the vice president of Theokol company asked to suspend the meeting for 5 minutes. Then, Jerry Mei Sen, president of Theokol, said, "We must make an operational decision." Boyce Jolly immediately realized that in order to please the main customer NASA, the attitude of the company's directors had changed from "don't launch" to "can launch".

The discussion within the company lasted for 30 minutes instead of 5 minutes. Engineers including Boyce Jolly were excluded, and four senior managers voted for the launch. Boyce Jolly stood up, grabbed the burnt photo of O-ring and put it on the table in front of four senior managers. But they don't even look. The boss immediately connected the video conference and informed NASA that Theokol's attitude had changed and Challenger could be launched. In the following period of time, NASA has been asking Theokol about the launch, but it just didn't ask Theokol's top management why they suddenly changed their minds. They just asked Theokol to write down the reason why they changed their mind. When the fax containing the new proposal reached Cape Canaveral at midnight, NASA had made up its mind to launch Challenger the next morning. So the tragedy happened. ...