| Challenger Essay, Research Paper
It was a cold, crisp, and damp morning on the Florida Space Coast as the space shuttle Challenger raced through the sky at speeds approaching mach 2 at an altitude of 104,000 feet when something went perilously wrong. All of America watched, including the family members of the seven doomed crew members, as Challenger exploded into an expansive ball of fire, smoke and steam. An “Oh. . . no!” came as the crew?s final utterance from the shuttle as the orbiter broke-up. As the reality of what she was seeing became apparent, Pilot Michael John Smith?s daughter, 9 year old Erin Smith, could be heard yelling, “Daddy! Daddy! I want you, Daddy! You promised nothing would happen!” Unfortunately, the events of that tragic day could have been easily prevented. Weather had been the main cause for five delays during the last month. The launch had been carried out in spite on the fact that weather was the worst it had ever been in NASA?s history of manned space flight. With so many !
delays encountered in that twenty-fifth shuttle mission, NASA had become careless in getting Challenger on its way. As Challenger sat on the pad awaiting it?s ill-fated mission, there were signs that there was something wrong with the Right hand SRB (Solid Rocket Booster). Nevertheless these signs were ignored by a neglectful staff whose only concern was scheduling and not safety. Also, at the time of the accident, for purely monetary reasons, the shuttle had not been fitted with a means of escape for the crew in the case of an emergency; a fact not revealed until after the accident. Though the Space shuttle was the cutting edge of technology at the time, new advancements in technology make the Space Shuttle old, unsafe, inefficient, and not cost effective. However, because of cut backs in funding, NASA is unable to make any advancements in it?s technology to prevent another catastrophic accident for the space program. Also as a result of the cut backs, NASA has had tro!
uble keeping the existing space shuttles? hardware kept up. The effects of the accident were numerous; the space program was shut down for three years. Also the effects on the NASA staff were immense, leaving a feeling of guilt and fear. On January 28, 1986, the space shuttle Challenger and it?s crew embarked on a mission to broaden educational horizons and promote the advancement of scientific knowledge; their mission was cut short in one of the most tragic and most easily prevented tragedies in America?s history in space.
Before the accident, the 51-L (This mission?s assigned number) mission was supposed to be remembered for many reasons. One reason was that this was to be the twenty-fifth space shuttle mission. Another reason was that this was to be the first shuttle launch from pad 39-b which hadn?t been used since the Apollo missions. However, The major reason was this was to be the first crew to include a civilian member. Sharon Chista McAuliffe was chosen from a pool of 11,400 applicants. McAuliffe, 37, was a social studies teacher in Concord High School in New Hampshire. While in space, she planned to still teach two lessons entitled, “Where we?ve been, where we?re going, why?”, to her class. Then, at T plus 1:13, the mission and its crew became remembered for other, more disastrous reasons. An O-ring in the right SRB shattered in the extreme cold and began allowing liquid hydrogen to leak then explode incinerating the seven crew members, destroying the valuable payload, and bring!
ing the space program to a halt for nearly three years. America listened a long ten seconds before “?the commentary was resumed in a tense monotone”(Lewis, p21);
“Flight Controllers are looking very carefully at the situation. Obviously a major malfunction. We have no downlink. We have a report from the flight dynamics officer that the vehicle has exploded. The flight director confirms that. We are looking at checking with recovery forces to see what can be done at this point. Contingency procedures are in effect. We will report more as we have information available?”(Lewis, p21)
“Major Malfunction”, a phrase that stuck with everyone watching the launch that day. Although later, flight commentator Nesbit would be commended for remaining calm by some people, many people described the statement as “the understatement of the century”.
Following all the delays caused by the weather over the past five days, the launch was rescheduled for the morning of January, 28th. A cold front with high winds was forecasted to pass through east central Florida. However, the winds were expected to die down, and the morning was expected to be clear but very cold. Temperatures were expected to fall into the low twenties, a rarity for the sub-tropical Florida climate. “Mission managers for NASA assessed the possible effects of the cold weather on the launch, but the only threat they perceived to the launch safety was the ice on the pad structure?Ice breaking off the structure during launch could damage Challenger?s heat shield.”(Lewis, p4) Ice inspection teams visited the launch pad three times on the morning of the 28th. Their job was to find any debris that might be blown out by engine exhaust. They found a layer of ice ranging from one-eighth to three inches thick on the launch pad caused from allowing water to dribb!
le to prevent the pipes from freezing. Similar ice problems had prevented the space shuttle Discovery from being launched a year earlier, regardless of that, the Challenger was allowed to proceed with the launch. Weather conditions for this launch were the worst in NASA?s history of manned space flight. However, the weather was a concern for more than one reason. Separate from the problem the ice posed for the launch; the cold would prove to be a concern for the O-rings in the SRBs, holding back the extremely flammable liquid hydrogen. “The night before liftoff , engineer Roger Boisjoly had implored his supervisors at Martin Thiokol – the Utah company that made the solid rockets that boost the shuttle into orbit- to recommend that NASA delay the launch. The cold, he said — temperatures would fall to 27 degrees that night – might effect the rubber O-ring seals, thus allowing exhaust gasses to leak from the rocket joints. If that happened he said, Challenger could explod!
e on the launch pad. But Mission 51-L – America?s 53rd manned space flight – lifted off without a hitch, riding a shaft of fire toward orbit seven minutes away. In Morton Thiokol?s conference room, Boisjoly turned away from the TV and remarked quietly to a fellow engineer Bob Ebeling, “Well, we dodged the bullet on that one”?Seconds later Boisjoly was fighting back tears. He struggled back into his office, staring at the walls, his mind blurred by images and the contrail of smoke and steam stretched across the sky.”(Lamb, p1) The O-rings were made of materials called elastomers. Elastomers have several problems. When they get hot, they become gummy and sticky, and when they become cold they become brittle, as in the case of the Challenger. During the investigations an experiment showed how brittle the O-rings would have been. A piece of the same type of O-rings used in Challenger was placed in a glass of ice water for a few minutes. Upon being removed from the water, i!
t was gently tapped on the table top. The O-ring shattered into pieces. The O-ring used in the experiment was still 5-10 degrees warmer than the actual O-rings in the Space shuttle. The slight tap given to the O-ring in the experiment would have been nothing compared the vibrations encountered in rockets propelling a 40 ton Space Shuttle though the atmosphere at 1,400 miles per hour. In the end the negligent thinking of the weather and the O-rings that proved ultimately catastrophic for the Challenger and it?s crew.
There was great political pressure on NASA officials to launch Challenger as early as possible after a month of frustrating delays. It was rumored that the administration was anxious to have challenger in orbit by February 4th when President Regan was due to deliver his State of the Union message. It was suggested that plans had been made for a live communications hookup with challenger during the broadcast of the message. Scheduling was also tight because the space agency had scheduled 15 launches for 1986, compared with only 9 in 1985. Then 19 missions were planned for 1987. The delays in the launch of Challenger, and before that Columbia, were threatening to disrupt the schedule for the next two years. The dominant source of pressure to get the Challenger off the launch pad was Jupiter, the target of two scientific spacecrafts, Galileo and Ulysses, to be launched in the spring of 1986 in order to hit the planet with minimum energy trajectory. If the probes missed !
their window, it would not return until July 1987. All this put great pressure on NASA to make the fatal decision to forgo safety in exchange for scheduling.
As Challenger began its accent, there were many warning signs ignored that would have prompted immediate abortion of the launch. Before the shuttle even made it off the launch pad, two black plumes of smoke were visible on the side of the SRB, but it went unnoticed. Those two black plumes burned at a temperature of 5,600 degrees, burning a hole through the half-inch steel case holding the liquid hydrogen and allowing it to leak through the O-rings being shattered by the cold and vibrations of the rocket boosters. Engineers noticed the smoke but did not acknowledge fact that anything could go so seriously wrong, and passed it off as unrelated anomaly. Then again at 59 seconds into launch, 14 seconds before the explosion, there were eight giant bursts of flame originating from the SRB that also went ignored. Following that at 1 minute into launch pressure began to rapidly fall in the right-hand booster, showing a possible leak, by this point the explosion was too large and!
the shuttle was enveloped in flame. Now all NASA could do was watch as the shuttle was destroyed. It was not until weeks later that an investigation team realized how easily it could have been prevented. Because NASA was so preoccupied with getting up to schedule, no one was looking for any signs of failure.
“Beyond the pall of smoke and descending wreckage a lone parachute appeared, drifting casually down toward the sea. It was the 54 foot drogue in a parachute decent system of one booster, a system designed for the recovery of the boosters at sea. Highly visible against the dark blue of the sky, the parachute, still attached to the forward section, or frustum, of the booster, led hundreds of watchers to hope that the crew was drifting down to safety and would soon be rescued. The lack of such a launch escape system on the orbiter was not popularly known.” (Lewis p21) It was suggested that a escape system be included in the proposed replacement shuttle, but it was met with opposition for not being feasible. However, an escape system could be put in without too much trouble. The Saturn 5 rocket had a escape system; if an explosion impeded the crew module would be pushed to an altitude of 3,000 feet above the rocket and then land in the ocean with the parachutes used for re-e!
ntry. In a shuttle, however, if one were to try and go out the top window they would hit the high vertical tail and get sliced in half. If one were to try and go out the side window they would hit the wings ending in the same fate. The escape window would have to be pretty narrow. The crew would only be able to escape the shuttle without any equipment except their helmet, flight suit, and a parachute. Even as crude a system as it is, it could have saved the lives of the crew of Challenger from their fiery death.
An advisory committee came to the conclusion that our space program is too reliant on the Space Shuttle for access to space. “The panel noted that the vehicle tends to be complex with limited margins; it has not realized the promised cost savings; and should it fail catastrophically it takes with it a substantial portion of the nation?s future manned launch capability and, potentially several human lives.”(Worsnop, p1) Government funding cut backs have cast doubt on NASA?s ability to keep up it?s four shuttle fleet. “NASA personnel found cracks in the hinges of the two doors on the shuttle?s underside that are supposed to close when the external fuel tank drops away minutes after liftoff. If the doors do not form a tight seal after closing, the vehicle could be destroyed when it re-enters the Earth?s atmosphere at the end of the mission.” (Worsnop, p1) The Space Shuttle, once regarded as the cutting edge of technology, is becoming obsolete. The Congressional Office of T!
echnology Assessment noted that the shuttle?s obsolescence has many aspects to it. After a certain amount of flights, metal fatigue makes the shuttle unsafe. Also, replacement parts for the shuttle may no longer be manufactured. “NASA engineers are particularly worried about another problem, like that which caused the Challenger accident, occurring in one of the other shuttles.”(Patrick, p1) “With the system and the risks involved, there will be an accident again someday. 35 years of space flight had proven to be more expensive and more dangerous than it is worth.”(Price, p1) After the Challenger accident the odds of another accident was put up to 1 in 78. Now a more recent calculation put the risk at 1 in 248. Yet, these are the same people who told us the rate was 1 in 100,000. Such considerations lead the panel to propose that the shuttle be gradually taken out of service. The transition period will be over many years, but some of the burden being carried by the spa!
ce shuttle will begin to decrease immediately. There have been over 280 first time anomalies in the space shuttle in the past year alone. NASA has had to resort to “cannibalizing” components from one shuttle to another. Though the shuttle was once state-of-the-art technology nearly 20 years ago, now its technology is becoming obsolete.
As a result of the space shuttle Challenger disaster, the space program was halted for three years as NASA research teams searched for the cause of the terrible disaster. Previously assembled shuttle components were taken apart a piece at a time and searched millimeter by millimeter for any imperfections. Every frame of video, taken from every angle were analyzed. Every byte of computer records were scrutinized. “Mr. O?Connor – who flew on the shuttle Atlantis three months before Challenger was destroyed – said his next mission wasn?t until 1991.” (Price, p1) But there more to the effects than the investigations; there were also many emotional issues that had to be faced. “For the Challenger mission, Robert B. Sieck was Director of shuttle operations at Florida?s Kennedy Space Center – a position he still holds. He is also 57, balding and soft spoken. On the wall of his second floor office is a formal portrait of the Challenger Crew, autographed by the seven members. !
There is also a quote from Teddy Roosevelt that he hung after the explosion. It says ” the credit belongs to the man who spends himself in a worthy cause; and if he fails, at least he?ll never be with those cold and timid souls who know neither victory nor it?s pursuit.” “There was a high level of schedule pressure.”(Lamb, p1) When asked “How fast did you get to wondering if it was you fault?” he replied, “Pretty quickly. The hardest thing for me to overcome was my guilt. Although a review showed that nobody at Kennedy Space Center was to blame, we were all members of the team that allowed a launch to occur that shouldn?t have occurred. There is a feeling that is was our fault, and some still carry that today.”
There were many ways that the challenger accident could have been prevented. The cold weather and it?s interaction with the O-rings was the main cause of the Accident. The shuttle should never have been allowed to be launched in that kind of weather. If the program hadn?t been so rushed, the staff would?ve been able to more carefully examine the reality of launching a shuttle in that weather. Even after the shuttle?s launch was started, there were numerous signs on what was to happen. However, these signs were neglected by a tense, rushed staff, and nothing was caught in time. If everything had happened the way it did, the crew could still be alive if some sort of escape system had been installed. The crew might have had enough time to escape be for the explosion enveloped their shuttle. As the Space shuttle program approaches 20 years in service, the technology is becoming more and more out of date. The shuttles have become old and unsafe, and a new program will soo!
n have to take their place. On January 28, 1986, the space shuttle Challenger and it?s crew embarked on a mission to broaden educational horizons and promote the advancement of scientific knowledge; their mission was cut short in one of the most tragic and most easily prevented tragedies in America?s history in space.
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S2 : The Causes of the Scientific Revolution
Science, in it?s simplest forms, emerged about five millennia ago. Then in around the second century the accumulation of wealth and leisure brought about the introduction of curiosity and science began to make small advancements. Aristotle, a famous Greek scientist and philosopher, believed that the cosmos was based on the notion of an enclosed universe consisting of concentric, crystalline, spheres revolving around a stationary Earth. This “Geocentric” universe was the basis for both the Roman and Greek sciences. Then through the Middle Ages and the Renaissance the public?s concern turned immensely to the Christian church which remained essentially ambivalent the Greek and Roman sciences and philosophies. Thus little if no interest was paid to the sciences. The devotion to the RCC (Roman Catholic Church) brought along with it a massive scientific regression that would last for hundreds of years. Then, seven centuries later the Reformation, the immense movement away fr!
om the traditional Christian beliefs, brought along with it a uprising of Rationalistic views. Rationalism is a theory that contends that the most fundamental knowledge is based on reason and the truth is found by rational analysis of ideas. One of the first influential rationalistic scientist was Roger Bacon. Bacon?s most consequential concept was the Scientific Method, a method of gathering and interpreting information that follows a fixed pattern of research. One of the effects of his Method was that it quickened the pace of scientific discovery. Also, it changed the way that new scientific knowledge was judged and accepted. One of the first scientists to use the new Scientific Method was Galileo Galilei. Galileo was a pioneer of modern physics and telescopic astronomy. The discovery of the telescope was the turning point of his career. With his discovery he was able give birth to a new science of planetary motion. That science was the basis for his belief that w!
e lived in a “Heliocentric” Universe, or sun centered universe in which the planets revolve around a relatively stationary sun, instead of a Geocentric Universe. This radical new idea brought the RCC to bring him before the Religious court and condemn him as a heretic. Another influential scientist was Sir Isaac Newton. Newton made contributions to every major area of scientific and mathematical area of study of his generation. His most significant mathematical discovery was laying the foundation for elementary differential and integral Calculus. The exploration of light and physics were the areas of study that Newton is most famous for. His greatest achievement in the optical field was the discovery that white light is not a simple homogeneous entity, but rather a mixture of many different types of rays. Newton?s most noted discoveries are in the area of Physics and celestial mechanics. Those discoveries were the basis for his three Laws of Motion. In the end, the !
rationalist ideas of the great scientists of the time and the general rationalistic attitude of the people all played a crucial role in causing the Scientific Revolution.
Sir Francis Bacon urged scientists to follow a fixed pattern of research, because of this he developed the Scientific Method. The first step of the Scientific Method was careful examination and observation through experimentation; the second step called for the use of reason to interpret the results. From this scientists could draw valid conclusions with which could be tested for further experimentation. Bacon?s method used inductive reasoning, acquiring knowledge by observation, unlike the Greek method of deductive reasoning, using accepted generalizations and then with reason finding the specific details, which totally avoided experimentation. The impact of the Scientific Method was felt in two major ways. First off, because of the method?s ability to better analyze how nature really worked, it largely speed up the rate of scientific discovery. Then, more importantly, it changed the way knowledge was judged and accepted. Soon the educated public no longer accepted !
explanations that were rooted in miracles, supernatural powers, or magic. The Scientific Method, reason, and mathematical logic became the only acceptable source for reliable knowledge. The Scientific Method along with the Heliocentric theory became the foundation of the Scientific Revolution and is still widely used today.
Galileo Galilei was one of the first scientists to use the Scientific Method. Amazingly Galileo first entered the University of Pisa as a medical student, but he soon became interested in mathematics and left without a degree in 1585. Word of a new invention that would magnify distant objects in Holland had caught Galileo?s attention. With a detailed description of the device, Galileo set out improve on it and use it in his studies. By 1609 Galileo had a 20x magnification telescope that he used to see the lunar mountains, the stars of the Milky Way, and previously unnoted “planets” revolving around Jupiter. Galileo is also credited with finding the strange phenomenon that would later be known as the rings of Saturn. Galileo published his findings and was met with immediate opposition from other scientists until they could build their own telescopes to prove his findings. He was made court mathematician at Florence, Italy, freeing him to further pursue his research. H!
e observed that the planets do revolve around the sun and became a firm believer in the Heliocentric World System. He was vigorously opposed by the Christian church because the Bible was seen as supporting the Geocentric Theory. Despite his argument the RCC issued a edict, or religious law, against Copernicanism, or the Heliocentric theory. Following this Galileo turned his attention to his earlier studies of motion. He was trying to develop the laws of motion necessary in a Heliocentric universe. His studies of brought him very close the laws of inertia and acceleration, the first two laws to be discovered later by Isaac Newton. One of the better known physical laws attributed to Galileo is his Law of Falling Bodies. His law says that two objects of different weights will still fall at the same rate. He proved this in a public demonstration at the tower or Pisa by dropping two cannonballs of largely different weights off the tower. Everyone was amazed when both balls!
landed simultaneously. Galileo is equally remembered for his confrontation with the RCC. Galileo was ordered to never teach or defend Copernicanism in public and to denounce his own belief in it. In June 1633, Galileo was condemned to life imprisonment for “vehement suspicion of heresy”. Galileo?s sentence was swiftly commuted to house arrest. Galileo continued his studies in the hopes that his successors would peruse it. Galileo?s discoveries would play an important role in the Scientific Revolution.
Sir Isaac Newton made fundamental contributions to every major area of science and mathematical concern of his generation including, Calculus, optics, gravitation, and astronomy. Newton Laid the foundation for elementary differential and integral Calculus. The “method of fluxions,” as he termed it, was the basis on his crucial insight that the integration of a function, or finding the area under its curve, is merely the inverse procedure to differentiating it, or finding the slope of a curve at ant point. Even though Newton could not fully justify his methods, rigorous logical foundations for the Calculus were not developed until the nineteenth century, he receives the credit for developing a powerful tool of problem solving and analysis in pure mathematics and Physics. During the plague years Newton had made a revolutionary discovery. He had reached the conclusion that white light is not a simple, homogeneous entity, as natural philosophers since Aristotle had believed. !
When he passed a thin beam of sunlight through a glass prism he noticed the oblong spectrum of colors, red, yellow, green, blue, and violet, that formed on the wall opposite. Newton showed that the spectrum was too long to be explained by the accepted theory of the refraction, or bending, of light by dense media. Newton argued that white light is really a mixture of different types of rays, that the different types of rays are refracted at slightly different angles, and that each different type of ray is responsible for producing a given spectrum color. These discoveries led Newton to the logical conclusion that telescopes using refracting lenses could never overcome the distortions of chromatic dispersion. He therefore proposed and constructed the first reflecting telescope which the prototype for today?s largest and most advanced optical telescopes. Newton?s greatest achievement was his works in Physics and Celestial Mechanics, which culminated in the Theory of Univer!
sal Gravitation. The well known story that Isaac Newton discovered Universal Gravitation when an apple fell from a tree onto his head is a myth. Newton succeeded in showing that a body moving in an elliptical path and attracted to one focus must indeed be drawn by a force that varies as the inverse square of the distance. He further demonstrated that the planets were attracted toward the sun by a force varying as the inverse square of the distance and generalized that all heavenly bodies mutually attract on another. Thus he reached his three laws of motion:
1)Law of Inertia
Every body persists in a state of rest or uniform motion in a strait line unless compelled to change such a state by an impressing force.
2)Law of Acceleration
The change of motion of a body is proportional to the force acting upon it and takes and takes place in the direction of the strait line along which that force is impressed. To every action there is an opposite and equal reaction.
3)Law of Gravitation
Every body in the universe attracts any other body with a force directly proportional to the square of the distance between them.
Given the law of gravitation and the laws of motion, Newton could explain a wide range of phenomena such as the eccentric orbits of comets, the cause of tides and their major variations, The precession of the Earth?s axis, and the perturbation, or variations in it?s orbit, of the motion of the Moon by the gravity of the Sun. Newton?s discoveries and laws play a vital role in most all sciences today and played a crucial part in the Scientific Revolution.
Rationalism played the most important role in the Scientific revolution. Without the rationalistic views of Francis Bacon, Galileo Galilei, and Sir Isaac Newton science would never had taken shape the way it did. Francis Bacon developed the Scientific Method which would lay down a path for future scientists. Galileo Galilei used Bacon?s method to prove that the Earth and other planets revolve around the Sun, rather than the Sun and planets revolving around the Earth. He also improved on the technology of the telescope to aid in the observation of the cosmos. Sir Isaac Newton improved on Galileo?s idea of the Heliocentric universe be proving that the planets moved in an elliptical path. Newton brought his three laws of motion to the sciences to explain the motion and gravitation of all matter in the universe. He also contributed to optical science by proving that white light is really a mixture of many different rays each reflecting a different color. This discovery al!
lowed him to improve the optical telescope, improvements that exist in today?s most advanced telescopes. All three of these scientists shaped how the public viewed the universe we live in. The rationalistic views of the public together with the rationalistic beliefs of the scientists of the time helped shape the Scientific Revolution.
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