Magazine article Technology and Children

Exploring Air and Space

Magazine article Technology and Children

Exploring Air and Space

Article excerpt

Humans depend on technology to explore air and space. From the first hot air balloons in the 1700s to the new Atlas V rocket, air and space technology has advanced at a staggering rate. The influence of air and space exploration has impacted each person around the world, whether he or she knows it or not. The technology that makes this exploration possible is a fundamental part of what students need to know about the world around them.

Air and Space Exploration and Society

Air and space exploration has provided many benefits to society, but it has also challenged people to adapt to changes caused by advances in transportation. For example, the spread of disease is more acute now that high speed trains and airplanes make travel quick, easy, and relatively cheap. If a person becomes infected with a disease-causing microbe, he or she may travel to another continent before any symptoms appear. In transit, the infected person may have come into contact and infected dozens of other people. Because transportation has hastened the spread of diseases around the world, research and development of vaccines and medicines have become more urgent. Another adaptation is the screening of people for diseases. Research and development of faster, more accurate tests for diseases have become priorities in part because of the influence of improved transportation.

Vehicular Subsystems

All vehicle-based transportation technologies have basically the same requirements. Vehicles need a body or structure, a method of propulsion, a method of guidance, a way to control speed and direction, a way to suspend the vehicle, and a support system in place to supply the vehicle with fuel, maintenance, and cargo and passenger loading and offloading.

Structure. Airplanes and spacecraft have bodies that are composed of a skeleton or frame on the inside and sheets of material on the outside that form the "skin" of the craft. Typically, the body shape is designed to reduce drag, a force acting on the nose of the vehicle that tends to retard its progress. Once in space, a non-aerodynamic vehicle may be launched from the nose of the rocket. In space, there is less need for vehicles to be aerodynamic. Air and space vehicles must be structured in such a way that they can carry people, cargo, or both. Notice that the Atlas V rocket in Figure I has a bulb-shaped nose cone. The nose of this rocket carries a payload, such as a satellite that will be sent to a faraway destination like the recent probe that was sent to Pluto. The rest of the Atlas V's stages are dedicated to holding an adequate amount of fuel in order to get the payload into space.

[FIGURE 1 OMITTED]

Propulsion is the means by which a vehicle is moved. Airplanes use propellers and gasoline engines or jet engines to propel the plane fast enough to take off and stay suspended in the air. Space vehicles initially travel fast enough to escape the pull of Earth's gravity. As a result of the huge energy requirements needed to get into orbit, conventional space-launch vehicles use rocket boosters. Both the jet engines on airplanes and the rocket boosters on space-launch vehicles operate on the same physics principles. It is a common misconception of elementary school students, and even adults, that jets and rockets propel a vehicle because the escaping gasses come out of the back and push against the atmosphere, but these engines operate on two principles: Bernoulli's principle and Newton's Third Law of Motion. Bernoulli's principle states that where a fluid (including engine combustion fumes) is moving at a relatively high velocity, there will be relatively low pressure. Where a fluid is moving at a relatively slow velocity, there will be relatively high pressure. The gas escaping out of the tail of jet and rocket engines creates lower pressure at the tail, and since no gasses are moving out of the front of the engine, there is higher pressure at the front. …

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