Реферат: The Challenger Disaster Essay Research Paper The
Название: The Challenger Disaster Essay Research Paper The Раздел: Топики по английскому языку Тип: реферат |
The Challenger Disaster Essay, Research Paper The Challenger DisasterThesis: I believe that in 1986 the space shuttle Challenger exploded due to low temperatures and the faulty design of one of the joints on an SRB (solid rocket booster).Why was this event unique? I believe this event is unique to the 1980 s because it was the first time a civilian, a school teacher, was going into space. That fact alone captured the attention of the entire nation. After the Challenger crashed the Space Program was revamped to make the safety of the astronauts the key issue.The Challenger: Originally scheduled to launch at 3:43 PM Eastern Standard Time on January 22, 1986, the Challenger liftoff was rescheduled five times due to bad weather. The final date scheduled for the Challenger s take off was January 28, 1986 at 11:38 AM Eastern Standard Time. On that morning the temperature outside was 36 degrees Fahrenheit, 15 degrees lower than any previous launch. The crew consisted of seven people. Michael J. Smith, the pilot, Francis R. Scobee, the commander, Judith A. Resnik, a mission specialist and the second woman to go into space, Ellison S. Onizuka, the second mission specialist, Ronald E. McNair, the third mission specialist, Gregory B. Jarvis, the first payload specialist, and Sharon Christa McAuliffe, the second payload specialist, and the first civilian to go into outer space. Sharon McAuliffe was a history teacher in New Hampshire when she applied to the Teacher in Space Program and was selected from more than 11,000 applicants to fly aboard the Challenger. McAuliffe was scheduled to teach two lessons while on the mission and then tour schools around the country and teach about the space program. On the morning of January 28, 1986 the skies were clear, the air was freezing, and the bright sun shone down upon the Challenger Space Shuttle, which sat atop launch pad 39B at Kennedy Space Center. Well below the lowest temperature any other launch had encountered, the officials at NASA decided to go ahead with the launch, anyway. The SRB s were ignited, and after less than a second black smoke was coming from the aft field joint on the right SRB, which led investigators to believe that grease, joint insulation, and O-rings were burning in the 5,800 degree escaping gasses. The gasses were escaping from the joint for a couple of reasons. One is the temperature was so low that the rubber O-rings could not expand fully quickly enough after the pressure of compression was released, another is that the SRB s are reusable, so due to prior use the diameter had increased. Another problem could have again been the weather. There had been a slight rainfall, so there may have been water in the joint that froze inhibiting proper secondary seal performance. At a little less than sixty seconds after launch a small and steady flame burning escaping gasses was shooting out of the joint and directed onto the external tank which contained liquid oxygen and hydrogen fuel. The flame against the external tank was 5, 600 degrees Fahrenheit finally caused the external tank to grow hot and weak. The side of the external tank gave way and liquid hydrogen started burning as well. At 72 seconds after take off a complex chain of events took place in a time span of two seconds, causing the Challenger to explode in mid-air and kill all crew members aboard. The Challenger was going at a speed of mach 1.92, and was at a height of 46,000 feet when it blew up, and its last transmission to NASA was at 73.62 seconds after take off. The SRB s have parachutes built into them so they can safely return to the ground after a normal launch. One of the parachutes came loose in the explosion and slowly drifted to the ground, leading the watching public to believe that the crewmembers had escaped by some escape system. What the public didn t realize is that there was no escape system on that shuttle or any previous one. An investigative commission called the Rogers Commission was set up to find out what went wrong in the Challenger disaster. The investigation involved over 6,000 people and lasted four months. The space program was put on hold for nearly two years while an investigation was held and shuttle systems and procedures were reviewed. Parts of the space shuttle were redesigned, a stricter regulations regarding quality control and safety, and new escape and rescue systems were introduced. Also, the final decision to launch is made by one of the astronauts who has his or her own safety and the safety of his or her crewmates as a top priority, not public opinion, budget, politics, or scientific needs. January 28, 1986 was the day that seven US astronauts died when their shuttle, The Challenger, exploded 73 seconds after launch. It was the coldest day in history that a shuttle had been launched. The cause of the accident was due to bad weather and the failure of the aft joint seal in the right SRB. This tragic accident will always be remembered in the space program and in US history. |