Katie

3/24/11
= Electricity in Space = A n analog signal can process and transmit information varying smoothing in time. However, a digital signal moves less gradually, such as in jumps. Different types of semi-conductors can be combined to create something that acts as a switch. Diodes are used to allow electricity to flow only in one direction. A transistor can be used as a switch, or to amplify an electric signal. Integrated circuits, such as those used in computers, contain many diodes and transistors.

In space, the use of electricity would be very important. If we were trying to reach Mars, we would need cameras to take evidence and samples from Mars. Also, without electricity, we wouldn't be able to get to Mars in the first place. We wouldn't have systems to navigate there, and each of the functions of the spacecraft would have to be preformed manually. If this system was used, there would be a lot more room for error, adding to the already high amount of possible error. This would make the mission to Mars nearly impossible.

//Ms. Mc: Good general overview of electronics and ideas about how we would use electronic devices on our mission. Please add a few more details such as the fact the ICs are super-miniaturized circuits so that electronic devices can be made smaller which would be important on our mission as space on the spacecraft would be a premium. You have great ideas, Katie -- please share them with us more in our writing and in our discussions in class. Please include the entry # in your title. 9/10//

5/4/11, Entry #2, History of Rockets

The first rocket-like machines date back to around 100 B.C. The first was called the Hero Engine. This machine used steam to make a sphere rotate.



Figure #1. Hero Engine

Some of the first real rockets made by the Chinese, using gunpowder filled tubes to shoot arrows. The Chinese used this invention in a battle against the Mongols, who called the rockets "arrows of flying fire." Because of this, the Mongols began developing their own version of rockets, causing rockets to spread to Europe. The Europeans developed the rocket further, enabling it to fly more accurately by launching it through a tube and improving the gunpowder.



Figure #2. Chinese fire arrow

In 1898, the idea to use rockets to explore space was formed by a school teacher. This same teacher also proposed the idea of using liquid instead of solid fuel. In the early 20th century, this idea was made practical when the first successful rocket was built that ran on liquid fuel. Though this rocket only flew for about 12 seconds, it was still an important step for the rocket. Soon many organizations began to form all over the world. One of these groups, located in Germany, invented to V-2 rocket, which was an important weapon in WW1. However, it came too late to change the outcome of the war. The Soviet Union launched the first satellite into orbit in 1957. It was called Sputnik. Soon after, many other satellites were launched, followed by rockets with humans on board. // Ms. Mc: Good general overview of the history of rocketry. When discussing history, it's important to include the names of the peopel involved and specific dates. As NASA has contributed so much to our exploration of space via rockets, I would include them as well. Good drawings. Please refer to them in your text (i.e., "as seen in Figure 1 . . . ). 13.5/15 //

4/4/11, Entry #3, Scratch Rocket media type="custom" key="8958072"

Instructions: Click red stop sign to stop the program. Make sure the volume is up on your computer. Click green flag to start the program. Enjoy!

Log Entry #4.

4/13/11
=Parts of the Rocket=

The nose cone of the rocket guides the air around the rocket to make it more aerodynamic. The body tube is the made structure of the rocket. The recovery system is a parachute or device that slows the rocket on its way back to earth, so that it lands safely in one piece. The recovery wadding protects the recovery system from the heat of the motor. The launch lug guide the rocket so that it comes of the launch pad straight. the fins help the rocket to continue to fly straight. The motor mount hold the motor in place. The motor powers the rocket.

//Ms. Mc: Good explanation of the functions of the parts. You have a couple of typos ("made" shoud be "main", "guide" should be "guides") so please read over your posts before posting them (-1). Don't forget to include a caption for your figures/graphs/tables (-1). 18.5/20//

Log Entry #5. 16/4/11 A Comparison of Rocket Mass to Height of Apogee

The purpose of this experiment was to find out how the mass of a rocket affects how high it flies. Inertia must first be understood to understand this experiment. Newton’s law of inertia states that an object in motion wants to stay in motion and an object at rest wants to stay at rest unless acted upon by an outside force. For example, if a ball is sitting on a table, it is going to stay like that until an outside force acts on it, such as someone touching it. When a rocket is sitting on the launch pad, the force of gravity is acting on it. When the engines are lit, the trust overcomes the force of gravity and the rocket’s inertia, forcing it off of the ground. When the powered flight ends, the movement of the rocket continues upwards because its inertia is enough to allow the rocket to overcome gravity. Eventually, however, the gravity overcomes the inertia and the rocket reaches its highest point, also known as apogee. The rocket starts moving downwards because of the force of gravity. Then the recovery system is released which increases the air resistance to slow the rocket’s fall. The rocket then lands with the force of the ground overcoming the force of gravity. It was hypothesized that, because force is directly proportional to the mass and acceleration of an object, the more mass the rocket has, the less high it will fly. The mass of the rockets varied from 42.8g to 48.7g. The apogee heights ranged from 71m to 135m. As seen in Graph #1, here is no relationship between the mass of the rocket and the apogee height. This shows that the mass of the rocket does not directly affect the highest point of flight. This disproves the hypothesis. A variable that could have changed to affect the results was the weather, such as which way and how strong the wind was blowing and temperature. Also, the independent variable was not changed significantly; the mass of the rockets only had a range of about 6g. Where on the rocket the mass was located could have also affected the results. For example, if most of the mass was located in the nose-cone, it might’ve had a different apogee than a rocket that had most of its mass located on the fins, even if the two rockets had the same amount of mass overall.

Entry #6

21/4/11
=Astronomy=

How did our moon come to revolve around earth?

When our galaxy formed, the sun was a star. Gravity created a ring around the sun, made of dust and gas particles. Small solid particles in the ring came together to make bigger and bigger particles. The earth was created from one of these. Earth and another object about the size of Mars collided together. This object got caught in the gravitational pull of earth, and became the moon.



Which is older, the Universe or our solar system? Or are they the same age?

Our solar system is much younger than the Universe. To be exact, it is three billion years younger. The Universe began through the big bang. After the big bang, the Universe was still very hot. Quickly, protons and neutrons began to form, and then helium and hydrogen. Our galaxy, the milky way, formed when gravity pulled together a disk of dust and gas around the sun, out of which planets formed.



//Ms. Mc: Good answers and pictures. Your caption for Figure 1 isn't quite right though; this is a planetesmal hitting Earth (-1/2). You also were to refer to your figures directly in your text and explain them (-2). Our solar system was created about 5 billion years ago whereas, the Milky Way was formed about 3 billion years after the Big Bang or about 12 billion years ago (-1). 6.5/10//

=Robot Challenge=

5/5/11
The program for the second robot challenge, called On the Edge, called for a sound sensor and a ultrasonic sensor. The program allows you to put the robot anywhere on the table, and it will go until right before it gets to the edge of the table. It does not begin until it hears a noise, which is what the sound sensor is for. The robot uses the ultrasonic sensor to detect how far away it is from something. The ultrasonic sensor was attached to the robot so that it was facing downwards, and therefore detecting how far from the ground it was. Because it sticks out the front of the robot, we could use this to detect the edge of the table because it will detect the change of distance when it sticks over the edge of the table.

As seen in Figure 1 below, the first block in the program for this challenge detects sound. It is a wait-for-sound block. This tells the robot to do nothing until it hears a sound that is loud enough (greater than 60). It uses the sound sensor, which is connected to port 2. The robot doesn't do anything until someone says go. The second block says to wait until the ultrasonic sensor detects a less-than 10 cm distance. The ultrasonic sensor, which is used in this block, is connected to port 4. Once it has detected that distance, the next block tells the robot to move forward in a straight line forever. This is a motion block, connected to ports C and B. The robot will move forward forever. The following block tells the robot to wait until the ultrasonic sensor detects a distance of more than 30 cm. These two blocks allow the robot move forever until a distance of more than 30 cm is detected. This also uses the ultrasonic sensor (still connected to port 4). The next block is a motion block, and makes the robot stop. It is connected to motor C and motor B. These last two blocks allow the robot to go forwards infinitely until it detects a distance greater than 30cm. The last block is a sound block that is set to tell the robot to say, "Watch out!" at a volume of 75.

This relates to The Mission to Mars because you wouldn't want the rover to fall off of an edge. If it can detect when it is about to fall off of an edge, it won't so it would survive longer (because it wouldn't crash).