Lexi

Log 1- 3/28/11... Definitions

Analog signals are different from digital signals. Analog signals are the transmitters of information through electrical signals. It is a signal that changes slightly in time. The electric currents inside analog signals change at just the right times. Analog signals vary smoothly. Whereas digital signals don't change evenly and jump steps. Each jump represents a series of numbers. Semiconductors are useful in electronic devices because their electric conductivity can be controlled by impurities. This gives you more control over it. Impurities are when a certain amount of atoms from a certain type of element is added to the semiconductor. This process is called doping. Diodes, transistors, and integrated circuits are used in electrical circuits for control in them and to be able to change the flow because of the semiconductors. Diodes allow the current to flow in only one direction. Transistors are used to amplify electrical current signals. Integrated circuits are used for the connection of lots of interconnected transistors and/ or other things for less space. Electronic devices are very useful in space missions when searching for life. The rocket electronics are used for take off. You use electronic devices to send signals between the rovers and the human controllers. The rovers are able to take pictures using technology. Electronics play a big part in space missions because they are the basis of how we get there and do our research. The rovers are driven from earth while the roam in space. They spaceship is powered by rockets which involve electronics. Everything that has to do with a space mission can related back to electronic devices.

Ms. Mc: Great overview of electronic devices and good ideas about what electronic devices might be used on a mission to Mars. 9.5/10

Log 2- 4/4/2011, History of Rockets

The first successful rocket was the hero rocket ﻿ or aeolipile, invented by Hero of Alexandria during 100 BC. The hero rocket uses steam as a propulsive gas. The fire heats up the kettle which ﻿boils the water, which turns the water into steam. The steamgoes out of the two spouts in the same direction, spinning the sphere in the opposite direction. This is an example of Newton's Third Law (equal and opposite reaction) and gave the idea of using thrust for rockets. Figure 1. Hero Rocket Sketch

Many rockets after this one were either myths or accidental rockets. The next great inventors who explored the world of rocketry was the Chinese. In the first AD century the Chinese created a form of gunpowder from saltpeter, sulfur, and charcoal dust. This was used as a way of creating tiny explosions when lit with fire. They were originally used as fireworks for festivals. Using this idea the Chinese next made the Chinese fire arrow. The Chinese fire arrow is a tube full of gunpowder attached to arrow which are launched with bows. The Chinese discovered that the arrow was able to launch itself on its own due to the power from the escaping gas (the first real rocket). The stick was attached for accuracy, to guide the rocket arrows.

Figure 2. Chinese Rocket Arrow

In 1898 modern rockets kicked off when Konstantin Tsiolkovsky (Russian School Teacher) put out the thought that space should be explored with the use of rockets. He also had the idea that rockets could travel greater distances if they used liquid propellant.

In March 16, 1926, Goddard achieved in the creation of a liquid propellant rocket. This was a major step in modern rocketry because it supported the idea of going to space. Also this is significant because it opened many new windows of opportunity for people to experiment with rockets. It also brought people one step closer to traveling to outer space.

The next great step in rocketry was the invention of V-2 rocket by the Society for Space Travel. It was created as a weapon to be used against London during World War II. Once V-2 was launched it was able to destroy whole city blocks. It was created as a weapon for war not for exploration of space.

Later the USA organized NASA space program to launch its very first satellite in order to keep up with the innovations of Germany. It was created for space exploration for the USA and as a rival for Germany's satellite.

Ms. Mc: Excellent summary of the history of rocketry and great drawings! A couple of points of clarification: 1) the Hero engine wasn't a rocket but and engine, 2) Russian designed Sputnik and not Germany. 14/15

Log 3- 4-5-11, Mission to Mars Scratch Video media type="custom" key="8960204" 1. Click red stop button. 2. Click green button. 3. Turn up volume. 4. Watch and Enjoy.

__Log 4- The Different Parts of a Rocket... 4-13-11__ // __**A**__ **rocket has many different parts.** **At the very top of the rocket sits the nose cone** **.** **The nose cone is used to cut through the airflow and direct the rocket through the airflow.** **The biggest part of the rocket is the body tube.** **All the other parts of the rocket are somehow attached to it. It is the fundamental body of the rocket.** **The recovery system, located inside the rocket, is the parachute.** **The recovery system/ parachute is used to float the rocket down to the ground so it is not damaged and can be used again.** **Also inside the rockets is the recovery wadding, a flame resistant material placed in between the rocket motor and the recovery system.** **It acts as a barrier between the heat emitted from the rocket motor and the recovery system, the wadding keeps the parachute from burning.** **The rocket motor can be used safely and can only be used once, before every lift off a new rocket motor need to be placed inside the rocket.** **The motor mount is the thing located inside the rocket that holds the motor in its place.** **The launch lug is used to direct the rocket off the launch pad during lift off, it helps the rocket fly straight.** **Lastly, on the outer side of the rocket, resides the fins.** **The fins help the rocket continuously to travel straight.** //

//Ms. Mc: Excllent definitions and labels! 20/20//

// **Log 5- Rocket Launch Lab... 4-17-11** //
The purpose of this experiment was to learn about parts of a rocket, how they work, how to build a rocket, and how to launch a rocket. When the rocket resides on the launch pad, the gravity and the launch pad were equal forces when compared, one pushing up, one pulling down. During the time when the rocket is taking off, gravity and the air resistance were acting against it, pushing/ pulling down, while the engines thrust was pushing the rocket up. Since the force of the thrust of the engines is greater the rocket moves upward. After the rocket engines were turned off the force of inertia keeps the rocket moving. The force of inertia was greater than the force of air resistance and gravity therefore causing the rocket to keep moving. It was hypothesized that if the mass of the rocket is small then the apogee would be higher than a heavier rocket because is less force needed to accelerate it. The apogee of the first rocket was 90 meters, the second rocket had an apogee of 68 meters, the third rocket had an apogee of 82 meters, the fourth had a 61 meters apogee, the fifth rocket had an apogee of 93 meters, the sixth rocket had an apogee of 84 meters, and the last rocket (7th) had an apogee of 82 meters. As seen in graph 1, The masses of the rockets ranged from 42.5 grams to 45.4 grams. A direct relationship is found between the apogees of the rockets and their masses. The increase of the masses at the same time as the increases of the apogees proved that the relationship is direct. The hypothesis made was proven because the hypothesis stated that there was a direct relationship. The hypothesis was proven true because 42.5 grams rocket had an apogee of 61 meters, 43.2 grams rocket had an apogee of 68 meters, and the 44.0 grams rocket had an apogee of 84 meters. The relationship between these numbers had an increase. Both the apogee and the weight of the rocket went up at the same time. One of the major things that affected the rocket apogee results was the wind. Also the fin size affected the rockets apogee.

__**Log 6. 4-25-11 Quarks and Galaxies**__ **When you break up a proton or neutron, the next smallest part is called a quark. Right now, only six quark types have been determined. Up and down quarks are inside protons and neutrons. As seen in Figure 1, protons have two ups and one down quarks. While neutrons have two down quarks and one up quark, as shown in Figure 2.** **Our galaxy, along with many other galaxies, formed approximately two million years after Big Bang broke up the matter. Galaxies are collections of stars and planets. Inside a galaxy, other than planets, majority of the galaxy is made up of stars, gas, and dust. We live in the Milky Way galaxy. The Milky Way is a spiral galaxy as seen in Figure 3. The different galaxy classes are spiral, elliptical, or irregular.**

//Ms. Mc: Good answers and pictures. A little more detail for your answers would have made them even stronger. What are the other 4 types of quarks? (-1/2). How did the galaxies form? (-1/2). 9/10//

__**Log 8- Summary of Challenge 3 Blocks - 5-9-11**__ This program tells the robot to move forward until it senses the edge of the table and stops. This is similar to a rover's programming because rovers are programmed to stop and start when near certain areas. Block 1- sound sensor wait block, connected to port 4, that tells the robot to wait until when a sound louder than 50 volume is sensed, then to start block 2. The robot waits until it hears a me say go which tells it to move on. Block 2- movement block that tells the robot to activate B and C servomotors and move forward (straight) at 75% power for an unlimited duration. The robot moves forward slowly until it detects something. Block 3- light sensor block connected to port 3 that tells the robot to generate light and wait until it reaches light that has less than 30 brightness. The robot puts out a light and detects the lightness of the gray table until it detects the blue tape on the table's edge. Block 4- movement block that tells the robot to activate B and C servomotors and move in no direction by braking. The robot makes no movement and has its brakes on. Block 5- sound block that tells the robot to play the sound file watch out at a volume of 75 and wait for completion. The robot plays watch out from its speakers.