Niara

Log Entry 1: Electronics

3/24/11

An electric current that changes and carries information is an electric signal. The two types of electric signals are analog and digital. In analog signals the electric current varies smoothly in time. An example of this would be an analog clock. On an analog clock, the hands move smoothly from one number to the next and carry the information of what time of day it is. Also, mercury-filled thermometers are considered analog devices because the mercury rises and falls smoothly when the temperature changes. Digital signals differ from analog signals because they don’t vary smoothly and change in jumps or steps. In a scenario where each step is represented by a number, the digital signal is represented by a series of numbers. With digital clocks, the time changes abruptly from minute to minute instead of stroking smoothly second to second. A semiconductor is an element that doesn’t conduct electricity very well but is a better conductor than non-metals. Semiconductors are important in electrical devices because their conductivity can be controlled when you add impurities to it. Semiconductors are also useful because they can be put together to form an electronic component that can control the electric current’s flow in the circuit. A diode is a solid component that allows current to flow in only one direction. Diodes assist in the control of the current’s flow and are used to control the current. Transistors are components that are used to amplify electric signals in a circuit. They are used as a switch. Electric signals can make transistors permit the flow of the current, or block the current’s flow. An integrated circuit is a tiny transistor that is used in computers and other electrical devices.

Electronics would be vital when travelling to another planet, especially when you are planning to explore its depth. Electronics would allow you to get to space, without them you would have no ship, space suit, booster rockets or controls for your ship. Electronics would help you stay connected with the people at the base on earth as well as help you send your discoveries back to them. Also, electronics would help keep you alive because if you didn’t have them you wouldn’t be able to breathe and you wouldn’t be able to control your space ship. Electronics are a necessity for space travel to help you survive and navigate.

//Ms. Mc - very good overview of electronics and some good ideas of how we might use electronic devices to search for life on Mars. Remember that we aren't sending people to Mars yet but you are correct that when we do, we will need many electronic devices to support life. A few more specific examples of how we would use electronic devices to on Mars' surface would have enhanced your entry (i.e, rovers, lasers to sample rocks, thermometers, etc.). 9/10//

Log Entry 2: History of Rockets 4/5/11

Rockets, A History The first object to fly in a similar style to that of a rocket was an aeolipile in 100 BC. It was invented by a Greek man named Hero of Alexandria and used steam to propel it. The Chinese accidentally created small rockets when put a gunpowder mixture into bamboo tubes to create explosions for religious festivals. After that the Chinese began to experiment with gunpowder and arrows. They then discovered that the arrows would propel themselves because of the power of the gunpowder. The first true rocket was used in the year 1232, during the war between the Chinese and the Mongols. The Chinese used their rockets to repel the incoming Mongol forces. Subsequently, the Mongols made their own rockets and are thought to be the reason for the spread of rockets to Europe. In Russia in 1898, a teacher named Konstantin Tsiolkovsky started the idea of using rockets in space exploration. Tsiolkovsky also thought of using liquid propellants to increase the range. Because of his influential ideas, Tsiolkovsky was named the Father of Modern Astronautics. In the early 20th century, Robert H. Goddard conducted rocketry experiments. In 1926 he achieved the first successful liquid-propellant rocket flight. His rocket was powered by oxygen and gasoline and although it only stayed in the air for 2.5 seconds and flew 12.5 meters in the air, the flight was monumental. In honor of Goddard's extensive work in rocketry, he was given the name, "Father of Modern Rocketry". In Germany, one rocketry society named the Verein fur Raumschiffahrt (Society for Space Travel) led to the invention of the V-2 rocket. This rocket was used against London n World War Two. After WWII, both the US and Soviet Union realized the great potential of rockets as military weapons. This realization led to the development of medium- and long range intercontinental ballistic missiles. Thus the start of the US space program. After this, the Russians and Americans began to launch their space programs into space. This brought us to the extensive exploration of space there is today. 

//Ms. Mc - very good summary of the history of rocketry. I like your drawings too. Please insert them in your text when you discuss them. Also, be sure to include a figure # and title for all photos/drawings. Just to be clear, the hero engine didn't fly but spun due to the thrust of the steam exiting the sprockets. This invention likely led to the idea of using gases to create thrust in order for rockets to fly. 14/15//

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Log Entry 4: Rocket Parts 4/13/11

The **nose cone** assists in the aerodynamics of the rocket. The main part of the structure, the **body tube**, encases the motor mount and recovery system and wadding. The **recovery system** is used to help ensure the safety of the rocket's landing and make sure that it's intact for future flight. **Recovery wadding** serves as protection to the recovery system from the heat of the ejection charge gases. The **launch lug** guides the rocket straight during the launch. **Fins** also help the rocket fly straight, but they straighten the rocket during flight. The **motor mount** holds the rocket's motor in place. Lastly, the **rocket motor** is a safe, single-use device that is ignited using electricity.

//Ms. Mc: Very good labels and definitions. What does the rocket motor do? (-1/2). I like how you made the terms a different color and font! 19.5/20//

Log Entry 5: launch analysis 4/18/11

The purpose of the rocket launch experiment was to see if the mass of the rocket would affect the height of the rocket’s apogee. The forces from the launch pad and the thrust were pushing up on the rocket while to forces of gravity and air resistance was pulling the rocket down. When powered flight began, the force of thrust overcame the downward forces which allowed the rocket to lift off the launch pad. It was hypothesized that if the mass of the rocket was too much or too little, that the rocket would not have the maximum apogee because the mass would either weigh the rocket down or not fly far enough because it's too light.

The results of this experiment show that the hypothesis was proved to be correct. The rockets with a high or low mass did not have an apogee as high as the rocket’s with a more central mass on a scale from 41 to 48 grams. The lightest rocket was only 41.5 grams while the heaviest rocket had a mass of 46.9 grams. The rockets in the center of the graph had masses ranging from 39.5 to 43 grams. As seen in figure 1, the rocket with the most central mass on a scale of 41-48 grams flew the highest. That rocket had an apogee of 119 meters. The more mass that the rocket had, the lower the rocket flew, thus the rocket with the highest mass had the lowest apogee (see data point), while the lightest rocket flew a little higher at 69 meters (see data point; outlier). The rockets with closer masses had apogees ranging from 82-93 meters. There is an indirect relationship between the numbers of data, indicated by the downward trend of the best fit line as seen in figure 1.

Figure 1: The effect of the mass on the apogee

In conclusion, the hypothesis was confirmed because the rocket with an apogee in the middle of the scale at 44.4 grams had the highest apogee. There are several ways errors could have altered the outcome of the experiment. First, the rockets were launched on different days; the highest rocket was launched on a calm, clear day while all the others were launched on gusty, overcast days. Also, the people handling the angle guns changed which could have changed how the apogee was recorded. In addition to this, the sample size of the rockets launched was too small to really collect data in a fair manner which had a great impact on the final data.

Log Entry 6: launch analysis 4/25/11 What is a galaxy?

A galaxy is a massive system bound together by gravity. Formed when gravity collapses matter, they consist of stars, gas, dark matter and dust. Galaxies orbit around their center of mass. They are categorized by their shape: elliptical, spiral or irregular. We live in the Milky Way Galaxy, which is a spiral galaxy, as seen in Figure 1. Mergers of galaxies often cause spiral shapes which are the most common. In the early Universe, galaxies were closer together which caused mergers to occur more frequently.

Figure 1. The Milky Way Galaxy What is a quark? A quark is a fundamental particle which contains an electric charge and a ‘strong’ charge. They combine in groups to form composite objects which are held together by the strong force. Protons and neutrons are each made up of three quarks. Quarks come in six different species, or flavors, each one having a specific mass. They are up, down, top, bottom, strange and charm.

Figure 2. Elementary Particles

Ms. Mc: Good answers but you forgot to put your pictures in (-4). You need to change your entry title as well (-1/2). 5.5/10

Log Entry 8: Challenge 1 5/5/11


 * The purpose of this challenge was to make the LEGO Mindstorms robot follow a path on the floor. The robot had to drive forward, turn right, drive forward, turn left, drive backwards, make two complete rotations, clap and display a smiley face. **

**The first block is a movement block. This block makes the servomotors B and C move forward with 50% power for 2.35 seconds. After this, it moves to the next movement block. The next block makes the robot turn right using the same servomotors at 50% power as well. However, this time, the robot is turning to the right at a 180-degree angle. After turning right, the servomotors move the robot forward again with the same setting except this time, the robot only moves forward 1.3 seconds. The next movement block also uses servomotors B and C at 50% power but turns the robot completely to the left at 180 degrees. The next movement block makes the robot move backwards for 1.5 seconds on 50% power with the same settings as the other blocks. The final movement block makes servomotors B and C turn in two full circles at 50% power for 1440 degrees. Now a sound block makes the robot clap using the applause setting, then a display box allows a smiley face to appear on the screen. Next, a waiting block makes the smiley stay on the screen for four seconds. Finally, the display block resets the screen so that the smiley face disappears.**

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