Space Shuttle Columbia

On February 1, 2003, the Space Shuttle Columbia broke apart during re-entry resulting in the loss of the seven crewmembers and the shuttle. For the next several months an extensive investigation of the accident was performed by the Columbia Accident Investigation Board (CAIB). The board published their final report in August, 2003 and concluded that the cause of the loss of Columbia and its crew was a breach in the left wing leading edge Reinforced Carbon-Carbon Thermal Protection System initiated by the impact of thermal insulating foam that had separated from the orbiters external fuel tank 81 seconds into the missions launch. During re-entry, this breach allowed hot gas to enter the wing’s leading edge and support structure which ultimately led to the breakup of the orbiter. The CAIB also discovered multiple flaws within the shuttle safety program, the hazard analysis techniques, communication and leadership between management and engineering, and an obstructive organizational culture. NASA responded to the Columbia accident by grounding all space shuttle missions for a total of 905 days while they complied with all the recommendations made by the CAIB as well as restructuring their system safety and communication procedures. Space Shuttle Columbia The Columbia STS-107 mission lifted off on January 16, 2003, for a 16-day science mission featuring numerous microgravity experiments. Upon reentering the atmosphere on February 1, 2003, the Columbia orbiter suffered a catastrophic failure due to a breach that occurred 81 seconds into the launch when falling thermal insulating foam from the left bipod area of the External Tank struck the Reinforced Carbon-Carbon (RCC) panels on the underside of the left wing. The orbiter and its seven crewmembers were lost approximately 16 minutes before Columbia was scheduled to touch down at Kennedy Space Center. Within this paper I will discuss the history, mission, and anatomy of Space Shuttle Columbia, the incident and the breakdown in communication and safety practices, as well as information found during the formal investigation by the Columbia Accident Investigation Board (CAIB). History of Space Shuttle Columbia The Space Shuttle Columbia was built in the years leading up to 1981 when it was the first space shuttle to fly into earth orbit on April 12th. There were four sister ships in the fleet over the next ten years: the Challenger, Discovery, Atlantis, and the Enterprise. The Endeavour was built to replace the Challenger that was destroyed in 1986. Columbia was the first on-line orbiter to undergo the scheduled inspection and retrofit program. It was transported August 10, 1991, after its completion of mission STS-40, to prime space shuttle contractor Rockwell International's Palmdale, California assembly plant. The oldest orbiter in the fleet underwent approximately 50 modifications, including the addition of carbon brakes, drag chute, improved nose wheel steering, removal of development flight instrumentation and an enhancement of its thermal protection system. The orbiter returned to Kennedy Space Center February 9, 1992 to begin processing for mission STS-50 in June of that year. Primary Mission The primary objectives of this mission was to research in physical, life, and space sciences, conducted in approximately 80 separate experiments, comprised of hundreds of samples and test points. The crew was divided into two alternating shifts to achieve the most productive use of time for each 24 hour period. The crew’s payload consisted of the following: first flight of SPACEHAB Research Double Module; Fast Reaction Experiments Enabling Science, Technology, Applications and Research (FREESTAR); First Extended Duration Orbiter (EDO) mission since STS-90 (Wilson, 2006). The expected duration of the STS-107 mission was 16 long days. Anatomy of the Space Shuttle The space shuttle is made up of over two million moving parts and 150 miles of internal wiring, making it the most complex machine ever created. Empty the space shuttle weighs in at 158,289 lbs and with the main engines installed it tips the scales at over 178,000 lbs. Once all the fuel and cargo are added, the space shuttle weighs an astounding 4. 5 million lbs. There are three main parts to every space shuttle, the orbiter, solid rocket boosters, and the external fuel tank. The solid rocket boosters and the external fuel tank are ejected from the orbiter while the space shuttle is leaving the atmosphere. The orbiter has enough crew space for eight crew members and a cargo capacity of 50,000 lbs. The Incident On January 16, 2003 the Space Shuttle Columbia was launched from Cape Canaveral, FL. 81 seconds into the launch a small piece of thermal insulating foam, the size of a small briefcase, impacted the leading edge of the left wing, damaging the Shuttle's Thermal Protection System (TPS), which protects it from heat generated from the atmosphere during re-entry. The foam had a total weight of 1. 67 lbs which is equal to the weight of 100 marshmallows and originated from the left bipod area of the External Tank. At the time of the impact the Columbia was traveling at 2300 fps through an altitude of 65,900 feet. The impact velocity of the foam was 775 fps. While Columbia was still in orbit, some engineers suspected damage as early as day two of the mission, but NASA managers limited the investigation, on the grounds that little could be done even if problems were found and therefore, never informed the crew of any possible damage. The damage to the left wing’s Reinforced Carbon-Carbon (RCC) panel provided a pathway for hot gas to enter the wing’s leading edge and support structure upon the attempted re-entry. This resulted in major structural and skin damage causing the loss of control and all vehicle data at 207, 135 ft above the Earth while traveling at 12,500 mph. The Columbia Space Shuttle broke up over north-central Texas just 16 minutes prior to its scheduled landing at Florida’s Kennedy Space Center. The Investigation Soon after the space shuttle disaster NASA created the Columbia Accident Investigation Board (CAIB) with the objective to determine the cause of the Columbia accident and to recommend ways to improve the safety programs and communication procedures within NASA. The Board published a working scenario along with several preliminary recommendations in advance of the final report which was published on August 26, 2003. Preliminary Recommendations The first of five recommendations the CAIB made was for NASA to develop an inspection plan for the examination of the Reinforced Carbon-Carbon (RCC) system components since the current inspection techniques were not adequate in assessing the structural integrity, its supporting structure, and the attached hardware. The RCC system is used on the leading edges of the wings, the area aft of the nose cap, and the area around the forward orbiter/external tank attachment structure due to the fact that these are the parts of the orbiter that are subjected to the greatest amount of heat during re-entry. At the time the CAIB conducted their investigation, they discovered and published that NASA did not fully understand the mechanisms that have caused foam loss on almost every space shuttle flight to date. They also found that the original and present day operating design specifications required the RCC components to have essentially no impact resistance. In order to mitigate future risk to the space shuttles and crew, the CAIB believed that NASA should look into the advanced non-destructive inspection technology and take advantage of it. The second recommendation made to NASA stated that they should amend their existing Memorandum of Agreement with the National Imagery and Mapping Agency (NIMA) to make it a standard requirement for every space shuttle flight to have on-orbit imaging available. The foam strike was first seen during the standard review of the launch video and high-speed photography, by the Intercenter Photo Working Group (IPWG) on the morning of Flight Day Two. The IPWG was concerned about possible damage to the Orbiter since this foam strike was larger than any seen in the past. No conclusive images of the foam strike could be found so the Chair of the IPWG asked management to begin the process of getting outside imagery from the Department of Defense (DOD) to help in damage assessment. This request, the first of three, along with the IPWG’s first report, including a digitized video clip and initial assessment of the strike, was distributed on Flight Day Two and began its journey through the management hierarchy. Even though the IPWG routed its request through the proper channels used during a mission, the management hierarchy yielded no direction, progress, or results. Therefore, the IPWG then routed its second and third requests for external DOD imagery through institutional, not mission-related, channels which diluted the urgency of the requests and the management viewed the requests as non-critical desires rather than critical operational needs. Communication did not flow effectively up to or down from the management hierarchy which lead to the three independent requests for imagery being subsequently denied. It was determined by the CAIB that the United States government along with NASA did not utilize every imaging resource it had in order to assess the damage of the Columbia while still in orbit. Recommendation three examined the repair capability of the space shuttle. The CAIB suggested that for all future missions to the International Space Station (ISS), NASA develop a method to inspect and conduct emergency repairs to the Thermal Protection System (TPS) tiles and RCC while docked at the ISS and recommended that a â€Å"comprehensive autonomous [†¦] inspection and repair capability† be developed for Shuttle missions that do not dock at the ISS. The end goal is to develop a â€Å"fully autonomous capability for all missions†, in the event â€Å"that an ISS mission does not achieve the necessary orbit, fails to dock successfully, or suffers damage during or after docking† (Troxell, 2009). The last two recommendations addressed the space shuttles imaging systems. The fourth recommendation recommended upgrading the imaging system to provide at least three useful views of the space shuttles from liftoff to at least Solid Rocket Booster separation, and further recommended exploring the possibility of taking additional pictures and observations of the space shuttle during launch using ships and aircraft. Recommendation five pertained specifically to the External Tank (ET) and the Thermal Protection System (TPS) imaging systems examination. The CAIB recommended modifying one of the two on-board umbilical cameras in order to â€Å"downlink high-resolution images of the ET after separation,† and further recommended that a similar system be put into place to â€Å"downlink high-resolution images of the underside of the orbiter’s leading edge system and the forward section of the TPS† (Troxell, 2009). Organizational Culture Communications procedures between managers and engineers at NASA were also investigated by the CAIB. The need to communicate effectively and efficiently between the individuals and organizations involved in the space shuttle program were found to be paramount, given the complex and high level of technology along with the extensive risks involved. The CAIB found that the original damage assessments contained substantial uncertainties for a variety of reasons, including management failures, communication breakdowns, inappropriate use of assessment tools, and flawed engineering judgments. The CAIB also determined that there were lapses in leadership and communication that made it very difficult for engineers and management to raise concerns and understand decisions. Management failed to actively engage and analyze the potential damage caused by the foam strike. Before the accident, flight managers had been under extreme pressure from Congress and the public to maintain launch schedules, and they had not followed established procedures for clearing unresolved problems. Based on these and other observations, the CAIB concluded that NASA was not a learning organization. Organizational learning is not one but several processes by which organizations seek to improve their performance by searching out the causes behind what they judge to be unacceptable results (Mahler & Casamayou, 2009). The CAIB concluded that the organizational causes to the accident included deficiencies in the command structure and safety monitoring systems, an inability to cope with strong external political and budgetary pressures, and an obstructive organizational culture. System Safety The CAIB found that NASA’s safety program was inadequate of achieving the level of safety necessary for the space shuttle program. As a result, the CAIB recommended that the safety system at NASA be restructured to include the system safety fundamentals. System safety is the name given to the effort to make things as safe as is practical by systematically using engineering and management tools to identify, analyze, and control hazards (Stephans, 2004) throughout all phases of the life cycle. At the time of the investigation, NASA’s definition of system safety was as follows: The optimum degree of risk management within the constraints of operational effectiveness, time, and cost attained through the application of management and engineering principles throughout all phases of a program. It was a great definition but NASA did not follow or operate under these fundamentals which were proven by the CAIB time and time again. They found that the system safety engineering and management was not vigorous enough to have an impact on system design, and it was hidden in the other safety disciplines and separated from mainstream engineering which proved extremely ineffective in regards to safety. They also found that the space shuttle safety program had conflicting roles, responsibilities, and guidance. Hazard Analysis The hazard analysis techniques used by NASA at the time of the accident were the Failure Modes and Effects Analysis (FEMA) and the Fault Tree Analysis (FTA). The CAIB found that the risk information and data from the hazard analyses were not communicated effectively nor could they find adequate application of a process, database, or metric analysis tool that took an integrated, systemic view of the entire space shuttle system. Post Columbia Procedures at NASA Once the investigation into Space Shuttle Columbia’s accident was finished, NASA shut down all space shuttle missions until they felt their system safety and communication procedures where brought up to par. This space shuttle grounding lasted 905 days and finally ended on July 26th, 2005 when the Space Shuttle Discovery successfully flew the STS-114 mission. System Safety NASA took the recommendation of the CAIB and restructured their system safety program. The purpose of the new system safety program within NASA is to ensure that the optimum degree of safety is achieved through management and engineering practices that minimize the number and magnitude of hazards in NASA systems. This is coupled with the application of system safety engineering analyses to detect and assess the nature and magnitude of risks so that they may be eliminated, reduced, or accepted depending on project requirements, schedule, and cost. This purpose is reached through the application of management, scientific, and engineering principles during all phases of a system life cycle. The ultimate goal is to avoid loss of life or injury to personnel, damage to or loss of equipment or facilities, project or test failures, and undue exposure to risk and adverse environmental effects. To date NASA has flown 19 separate space shuttle missions with no incidents under their new system safety program. NASA’s space shuttle fleet is set to retire after just two final missions. Space Shuttle Discovery is expected to launch on November 1st, 2010 and Space Shuttle Endeavour will launch no earlier than February 26th, 2011. Post Columbia Improvements NASA spent $1. 4 billion in an effort to improve the space shuttle after the Columbia incident. The most notable area of improvement was the External Tank. The bipod foam that caused the Columbia disaster was replaced with an electrical heater to prevent ice from forming. Another notable area of improvement was too the Foreign Object Debris (FOD) procedures which improved safety. They also added over 100 tracking cameras to view launches as well as cameras mounted on the External Tank and Solid Rocket Boosters. NASA also has two aircraft equipped with high-definition cameras which offer the unique perspective of a shuttle flying toward the viewer (Chien, 2006). All of NASA’s improvements seem to have worked so far. In the years following Space Shuttle Columbia’s accident, NASA reinvented their company from the ground up and is now used as a model company that others look to for advice and operational information. Conclusion The Space Shuttle Columbia accident may or may not have been preventable. There are numerous things that could have gone differently that might have given the crew a different fate, however, the accident happened in the least bad manner possible. The astronauts were able to enjoy themselves the entire mission, complete essential mission experiments, and reach a goal many of them had worked toward their entire lives. They had no knowledge that the shuttle was damaged and their deaths were mercifully swift. Columbia’s re-entry path over the U. S. made debris recovery far easier than if it had fallen over the ocean. Because so much debris and information was recovered it was possible to determine exactly what happened without any shadow of a doubt. It will certainly always be regrettable that the accident happened, but the fate of the Columbia crew could have been far worse. They will always been remembered as heroes.

Role Played by the French Revolution in France's Socialist History Term Paper

Role Played by the French Revolution in France's Socialist History - Term Paper Example Socialism falls as an economic and political approach that advocates for state-owned companies and state-restricted allocation of capital brought about as a result of democracy. The principles of socialism, in addition, takes account of demands for influential industries, utilities, banking and natural resources to be publicly owned as well as for publicly owned social services like healthcare (Jaures 2). France has had a very interesting socialist history. The French revolution has had a lot to do with the socialist history in that country. The roles played by the French revolution in France’s socialist history are the center of attention of this article. This article will discuss the roles that the French revolution played in the development of socialism, seeking to defend it over the communism theory. Background theory of socialism The term socialism dates back to 1832 from L. Pierre, an editor of the Parisian magazine, Le Globe. After that, socialism was defined with a var iety of meanings as the family of socialism bred from Western Europe to America, Russia, Australia, and Asia. It is misguidedly assumed that Russians came up with both communism and socialism and shipped them, when in reality they borrowed these principles of politics and economy from Western Europe and eventually invented their own edition of them. The many meanings of socialism developed in bits. This was from the disagreement on the ways by which a more evenhanded allocation of wealth in the public felt to be attained, a view of which no two socialist philosophies looked as if to concur. Marxist socialism projected the persuasive establishment of citizens’ autocracy. Conventional social democrats’ proposed parliamentary reorganization and trade unions. Syndic lists advertized a universal demonstration of the workers. Christian socialists advertized a severe appliance of the beliefs of the Bible as well as trade unions, or associations, as they referred to them. Addi tionally, no two socialist beliefs could concur on why scarcity existed or how it had taken place in the beginning (Doyle 4). Role played by French revolution in France’s socialist history The French Revolution stands as a whopping factor for developing the socialist theory. The French Revolution, in some way, set the arrival of the working class. It recognized the two critical circumstances for socialism: capitalism and democracy. The revolution preordained the coming of the bourgeois (socio-economic) class. The revolution also saw the development of political and economic interest groups, large-scale industries, and the working class. These increased figure and desires brought nervousness to the farmers who were angered with opposition and plagued by the industrial and commercial feudalism, and the moral unrest of the learned bourgeoisie; whose fragile sensibilities stand as a commercial and vicious society upset, all of which have slowly paved way to a new social crisis. I t paved the way to a novel and more philosophical revolution; an upheaval through which the working class will get hold of power in order to transform assets and principles. So stands the march and the interaction of social groups since 1789 that people wish to narrate. It proves always somewhat random to lay out clear limitations and divisions in the continuous and nuanced development of life. Nevertheless

An evaluation something on campus after closely studying this Essay

An evaluation something on campus after closely studying this something ,develop fair criteria topic can be a specific place,event,or service(must be on campus) - Essay Example The staff has been specifically trained and organized to manage the health of the students. There is enough medication for the students in the college and this leads to a better way of running the campus since there is not much time wasted on treating the students. One of the major drawbacks of the health care systems is that it has a paying fees for the service provided, which comes at a cost to the students who expect subsidised costs and cheap services, which is something missing from this system. The health care system also does not have enough space to cater to a large number of people at the same time, and this may prove to be futile if there arises a need to cater to a large number of students. Since all the students are eligible for treatments it basically depends on who can afford the treatment and who cannot. To meet the requirement of each and every student the college has made sure that the treatment comes cheap and not too expensive so that the people don’t have to think twice before going for the health care system. The health care center also offers health insurance for the students at a very nominal charge. This is done to facilitate health consciousness and awareness among the students of the college and to allow them to retain benefit from the college at the cheapest prices. The idea is to make sure that if anything happens to the students then the health insurance will cover the greatest of the greatest costs of the students and that shall also help him to undergo his treatment at low prices. Whenever a student visits the college a confidential health record is maintained by the college health center. This is done to maintain the privacy of the student and also in the best interest of medical ethics. There are certain rights which the patient has and these shall be understood in detail. The first and the foremost right the patient has is the right to be given quality treatment irrespective of the background of the

Business Plan Implementation Personal Statement Example | Topics and Well Written Essays - 250 words

Business Plan Implementation - Personal Statement Example Coral Reef Adventures will dive seven days each week and visit a variety of dive sites each day. With over 25 unique dive sites available off the coast of Palm Beach, divers will experience a truly remarkable diving experience. The Coral Reef will operate from a beautiful 38’ Canaveral Custom Boat or equivalent docked at the Riverian Beach Marina. The boat will be well equipped with a professional captain and crew to serve its guests. There will be a Certified Dive Masters on every trip, oxygen and Nitrox fills on board, complimentary soft drinks and snacks and a fresh water rinse area for all to enjoy. Coral Reef Adventures, Inc. will accommodate up to 25-30 customers at a time. The boat will be equipped with 9 well trained staff and state of the art equipment, to make each trip a safe and enjoyable adventure. The company’s mission will be to deliver a variety of programs and packages that appeal to all skill levels. It provides maximum frequencies and options to guests and demonstrates abilities to showcase best dive charter with the best service and safety conscience crew the Florida â€Å"Gold Coast† has to offer. Finally, it endeavors to provide extra value added amenities, the competition does not offer to all guests. My goal is to engender a business that performs at a consistent profitable level, and as my four Sons finish their educational careers, it is my intention to integrate each one into different functions of the business. I would like the company to have acquired 25 new boats from the current single boat in the next 10 years, and grow by an average of $ 2million per year in revenue. I will need to impart teamwork, good communication, reliability and responsiveness to my team. Besides, I will recruit those who have a passion for diving and have shown credible track record in doing honest and ethical business. I will also motivate my employees by reviewing their monthly paychecks upwards. The new technology and social

The effect of dystrophin on neuron development in the Central Nervous Essay

The effect of dystrophin on neuron development in the Central Nervous System - Essay Example The DMD is the human gene responsible for providing instructions for making dystrophin. Dystrophin is located in muscles such as cardiac muscles (heart) and skeletal muscles (movement). Small amounts of this hormone are present in the brain specifically in the nerve cells. In cardiac and skeletal muscles, this protein hormone is part of a protein complex which work together to protect and strengthen muscle fibers from injury during contraction and relaxation of the muscles (Hart 23). Dystrophin complex often act as an anchor for connecting each framework of the cells of the muscle with protein lattice and other extracellular matrix. Dystrophin may also play an important role in cell signaling through interacting with proteins which receive and send chemical signals. Little is known so far concerning the functions of dystrophin complex in nerve cells (Hart 24). Some studies have suggested that it plays an important role in the normal functioning of synapses and structure, which are sp ecialized connections existing between nerve cells where the occurrence of cell-cell occurs. In this paper, the focus of ascertaining the effect of dystrophin on neuron development in the Central Nervous System According to Shan and Lihsia (13) dystrophin protein plays an integral role in maintaining muscle membrane integrity. Shan and Lihsia showed that accompanying neuropsychiatric disorder and cognitive impairment often presented in most of the DMD proteins suggests that dystrophin plays an integral role in membrane-cytoskeleton function. The study involved growing c.elegans strains on the nematode growth medium plate at 21 degrees Celsius. Transgenic animals were then generated basing mello et al (1991) standard procedure. In order to generate Punc-119::dys-1 (pLC587), the researchers pieced together the 9.0-kb dys-1 genomic sequence obtained from WRM0611bE10 at an exon 30 with the untranslasted region of cDNA and 169-bp dys-1 3 and 3.9-kb dys-1 cDNA, and subcloned was joined in to the pBluescript II KS vector existing between NotI and XmaI. The researchers then crossed evIs78 (Punc-129::gfp and oxIs12 (unc-47::gfp integrated transgenes into the available respective strains with a view to visulize cholinergic neurons, and GABA. Synchronized the young adult animals of such strains and the synchronized dys-1 larvae for different stages were all mounted on the 2percent agarose pads and then scored for neuronal displacement with a 40? 1.3 NA Neofluar. This was done with an aim of using the microscope with the captured image, which was captured in a camera, along with the imaging software. Shan and Lihsia findings showed that DYS-1/dystrophin helps in regulating locomotion and muscle integrity. The findings of this study, also show that SAX-7 and STN-2/Y-syntrophin functions to maintain the neural integrity in c.elegans. In yet another study Hart Lidov, Timothy Byers, Simon Watkins, and Louis Kunkel (7) scientific study, this researchers came up with antibody (a nti 6-10), which was somewhat more sensitive that the immunolabel dystrophin which were previously available. The researhers then used this anti 6-10 antibody in to investgate whether the asoociation between systrophin and the nervous system. The findings of this study revealed that in the mouse, dystrophin is more abundant in the neurons of the cerebral cortices and the cerebral. This study also revealed that

Defining concept of design thinking Essay Example | Topics and Well Written Essays - 2000 words - 1

Defining concept of design thinking - Essay Example an a branch of career study which applies the sensitivity, creativity and innovativeness as well as coming up with executions and implementation strategy in order to bring out satisfaction of the consumers who intends to use the product and to cope up with the market competition. 3. Choose examples exploring the current literature on design thinking, its influences and its critiques and relate it to real world application of design thinking used as a strategic tool in business leadership. Some technological companies such as Google and Apple have in the recent past given room for about 20% of their employees to think and come out with their ideas in improving their services and the goods for the case of Google. For many consumers in the market the need is full satisfaction in which consumers need new products with development in operations. Design thinking has much influence on the profitability of the company. Taking for instance phone applications, most consumers will go for those phones with many features as compared to those with fewer features. These features are some of the products of ideas which in this case is design thinking. In addition design thinking brings about competition among the companies thereby resulting in high quality products. Of course there is aspect of critics coming from the social side. Most of the design thinking are associated with the destruction of the environment, exploitation due to high demand of the input place in implementing the se ideas. When we take for example the motor vehicle industry such as the Lamborghini which is a current design thinking product is very expensive as compared to other cars which are not highly designed but it is surprising to note that the raw materials are just the same. This makes us to believe that the increase in price is due to the designing services. Most of business strategic plans are based on the applications of the ideas from the management and other employees. After depict of clear

Teaching Personal Statement Example | Topics and Well Written Essays - 250 words

Teaching - Personal Statement Example This cooperation occurs between students and their peers as well as students and teachers. Social literacy is supported for example, where there is opportunity to work in groups, discuss issues, and contribution to class works. Appeal to the interest of children: this principle supports science literacy since it is based on a curriculum that responds directly to the interest of children. This provides opportunities for knowledge construction. The tenet also allows a constructivist teacher to recognize and stimulate the interest of children. This will support science literacy when for example, the teacher observes what children do, solicit the ideas of children, and propose activities that entice children. Teaching in terms of the type of involved knowledge: this tenet defines the kinds of knowledge helpful to constructivist teachers. Physical knowledge, conventional or social knowledge, and logico-mathematical knowledge may be used among children. This supports science literacy in that varying strategies are used for different types of knowledge. For example, with conventional knowledge, children are shown and told the information via direct instruction, in physical knowledge, the children are assisted in getting chances to act on things and their reactions noted while a teacher provides experiences in logico-mathematical knowledge through which student reorganize their own knowledge. Choosing content challenging children: this principle creates a culture of inquiry and develop teaching curriculum based on ideas which allow a very in-depth study. It supports science of literacy through providing activities appropriate for wide development levels. For example, it analyzes activities in terms of relationships and regularities. Promote reasoning among children: this principle supports science literacy because it encourages