Pranay

4/9/2012 Log Entry #1

Important Facts Needed to Send a Rover to Mars

Facts about Mars
 * Mars was named by the Romans for their god of war because of its red, bloodlike color.
 * Its surface appears reddish due to high quantities of oxidized iron.
 * The similarities between Mars and Earth are striking.
 * Mars has seasons similar to Earth, but last much longer.
 * Although Mars no longer has a global magnetic field like Earth, there are areas which are highly magnetized, a legacy from billions of years ago.
 * Mars has polar ice caps like Earth, but its atmosphere is too thin to sustain liquid water.
 * Mars is a cold desert world.
 * The most important question that scientists strive to answer is, “Can Mars support life?”

Facts You Need to Know Before Sending a Rover to Mars
 * In order to launch the spacecraft containing the rover, it would need to be designed with sufficient thrust and power to overcome the pull of Earth’s gravity.
 * You would need to know the orbit of both planets and plan to release the rover when the planets are close together.
 * The orbit of Earth and Mars only align every 2 years or so.
 * The launch path of the rover has to be precisely timed and angled to reach Mars at the appropriate point of its orbit.
 * The spacecraft or rocket ship should continue to have control of the rover to redirect it toward Mars if necessary.
 * You need to understand the conditions on the surface of Mars, such as its lack of magnetic field, extreme cold, polar ice caps, and thin atmosphere.
 * The rover must be protected from the intense heat of entering Mars’ atmosphere with an aeroshell, discarded prior to landing. The aeroshell is comprised of the heat shield and a backshell, which houses the parachute used to ensure the secure landing of the rover.
 * The rover needs to be designed to survive the surface conditions of Mars, with airbags to withstand the initial impact, utilizing solar power for energy and suitable wheels for the soft soil on Mars.
 * The rover’s electronic system needs to be designed for communication with Earth, and with critical scientific instruments for gathering information on Mars.

Ms. Mc: Good overview of Mars and its conditions. Good additions from class discussion too! 10/10

4/9/2012

Log Entry #2

**The History of Rockets** The first device to demonstrate the central principles of rocketry was known as an aelopile. Created by the Greek inventor Hero of Alexandria, the aelopile used the steam power of boiling water to move a hollowed sphere. As the steam passed through bent tubes attached to the sphere, its push, or thrust, on the tubes caused the sphere to rotate like a wheel. This concept of thrust was developed further when the Chinese discovered the explosive capabilities of gunpowder. It was used in both religious ceremonies and war. In a battle against the Mongols, they learned that tube shaped “fire-arrows” were not only powerful, but could launch themselves. Rocketry as we know it first began to emerge centuries later, in the late 19th and early 20th century. Konstantin Tsiolkovsky of Russia and Robert Goddard of the United States were two prominent figures who both offered significant contributions to rocketry. Proposing the idea of space travel with rockets, Tsiolkovsky earned the title “The Father of Modern Astronautics”. For experimenting with different rocketry concepts and developing the first liquid propellant rocket, Goddard was named “The Father of Modern Rocketry”. Although rockets did not lose their roots as a military weapon, as exhibited by the German V-2 rockets of World War II, many began to realize their potential space exploration tool. Peaceful organizations, like NASA, began to form, striving for the benefit and knowledge of all.





Ms. Mc: Great summary! Missing V2 rockets (-1/2). Very good drawings! Please refer to your diagrams in your text (i.e., "as seen in Figure 1"). 9.5/10

4/9/2012

Log Entry #3

media type="custom" key="14055560" Instructions for Running Scratch Simulation 1) Turn on your sound 2) Click the red stop icon if necessary 3) Click the green flag and enjoy!
 * 4) If the animation does not appear, click the "Learn more about this project" link

Caleb: The list of already accomplished steps was a fantastic idea! I thought that the size changes of the rover were a bit choppy, but that the rest of the project was very smooth. I also liked that there were so many sounds and the transitions between the sounds were great! Drake - Wow, great job Pranay! I love the artwork and the music. Although, it kind of seemed like the apogee was during the time when the background was Earth and Mars, not when the rocket was beginning to land. But besides that, everything was great! Awesome job!

4/16/2012

Log Entry #4

**Entry #4: Rocket Parts**

The nose cone, at the top of Figure 1, makes the model rocket more aerodynamic, allowing it to move through the air easily. The body tube serves as the frame of the rocket. It contains the recovery system and the rocket motor. The launch lug is the small barrel attached to the body tube. It helps keep the rocket straight when lifting off. Like the nose cone, the fins make the rocket aerodynamic and allow the rocket to move in a straight line. Inside the rocket, a parachute, ejected just as the rocket reaches its peak, is attached with string to the nose cone and with a shock cord to the body tube. The parachute is meant to allow the rocket to land safely. Near the bottom of the body tube, the motor mount holds the rocket motor in place. The rocket motor itself is a non-reusable motor filled with a solid propellant. When lit, it causes the thrust that launches the rocket. Lastly, recovery wadding is inserted just below the recovery system to protect it from the burning fuel of the motor. //Ms. Mc: great definitions and labels! 10/10//

4/18/2012

Log Entry #5



In order to launch Curiosity, the newest 2-ton Mars rover, a rocket powerful enough to propel such a heavy object is needed. At a height of 191 feet and weighing about 1.17 million pounds, the V-541 rocket has liftoff capabilities powerful enough for such heavy cargo. The Atlas V-541 is an ELV, or expendable liftoff vehicle, meant to provide the thrust required to send a spacecraft to Mars. Hence “541”, this rocket is comprised of a 5 meter nose cone containing the rover, 4 solid rocket boosters attached to the central common booster, and a one-engine Centaur, the cylindrical container inside the nose cone in Figure 1. The rocket has 2 different liftoff stages as well, and different parts are used in each stage. In the first stage, the rocket must lift off the ground and enter Earth’s orbit with the thrust from the fuel tanks. The solid rocket boosters help in this process. Then, the Centaur upper stage begins. In this stage, the power is provided to propel the rover out of Earth’s orbit to Mars. Ms. Mc: Great overview and diagram! Please include a title under the date for each entry. 10/10

4/25/2012

Log Entry #6

**Model Rocket Lab Analysis** The purpose of this experiment was to determine how a model rocket’s mass affects the height of its apogee, its maximum height when launched. Several model rockets of the same type but of different mass were built and equipped with the same engine and fuel. On the launch day, their masses were recorded, and the height of each rocket’s apogee was determined by using simple measurements and trigonometry. Each rocket was placed on a launch pad, and an electronic controller was used to send an electric current was used to ignite the fuel in the rocket’s engine. The burning fuel created a downward pressure, which in turn caused an upward thrust. This thrust allowed the rocket to overcome the combined force of air resistance and gravity, which was already in effect holding the rocket on the launch pad, and achieve lift-off. The fuel-propelled rocket accelerated into the air and entered a phase known as powered flight. When all the fuel was burned, there was zero thrust and the rocket coasted for a distance due to inertia before reaching its apogee and beginning its descent. Research states that an object of greater mass requires greater thrust to be propelled the same distance as an object of lesser mass. Therefore, it was hypothesized that when rockets of varying masses were launched with equal fuel, and consequently equal thrust, the rocket of greater mass would have a lower apogee because the same thrust would propel it a shorter distance. As shown in the equation Force = mass * acceleration, or acceleration = Force / mass, the mass of the rocket is inversely proportional to its acceleration. Since the thrust or force was the same, the rockets of greater mass, with a lower acceleration, would result in a lower apogee.

The masses of the tested model rockets ranged from 42.8g – 45.9g. The majority of the rockets accelerated upward to a height of 53.2m – 107.2m, excluding the outlier rocket that reached only 18.5m due to a measurement error. The data displayed in Graph 1 shows an inverse relationship between rocket mass and apogee. In other words, the apogee of a rocket decreased as its mass increased. The resulting data, especially the 42.8g rocket that reached a height of 107.2m and the 50.9g rocket that only reached a height of 53.2m, confirmed that the original hypothesis was correct, that the greater inertia of a massive rocket will result in a lesser apogee. In other words, the same amount of fuel, generating the same amount of thrust, propels a massive rocket a shorter distance than a rocket of lesser mass. In order to have more successfully performed this experiment, it would have been favorable to increase the sample size of rockets used, with a wide range of rocket masses to find clearer trends in the data. Increasing the number of launches of each rocket would have ensured the consistency of the data. Also, choosing a minimally windy day would reduce the chance of error caused by additional forces acting on the rockets, and ensuring that each rocket was built equally would have reduced the chance of error caused by imprecise fin placement.

4/30/2012

Log Entry #7

**Rocket Fin Redesign Lab**

In order to redesign the rocket fins, a “swept-wing” design was attempted, and the rocket fins were flipped upside-down. As seen in Figure 1, mini-fins, in the shape of small right triangles, were attached to the ends of the fins. Otherwise, the placement of the fins remained the same as the original. The inverted fins were expected to alter the flight path of the rocket, enabling it to execute a series of flips and rotations, as it soared upward. The design was not centered solely on achieving the highest apogee, as per the instructions. It did achieve the anticipated spins and a fine show for one and all, but fell far short of the original height.

Although additional small fins were added to the rocket, the swept wing design was measured to have a lower mass than the original. The standard rocket had a mass of 43.9g. For the second launch, the rocket had a mass of 42.9g. However, despite the reduction of mass, the swept-wing rocket flew 18.5m, far lower than the 88.5m flown by the standard rocket. This is likely because the larger side of the fins were facing upward, causing more drag. In addition, the use of mini-fins on the edges of the large fins affected the rocket’s stability as well.

5/4/2012

Log Entry #8

**The History of Robotics** Robotics is the study and use of robots. Robots are machines that can be used to perform manual tasks and simplify our work. The word ‘robot’ is derived from the Czech word for forced labor or serf. The creation of robots can be seen as early as several hundred years B.C., when motors were used to open doors in ancient Egypt and movable water clocks were built in Alexandria, Greece. During the Renaissance period, Leonardo da Vinci created a mechanical knight, as seen in Figure 1, and this theme was extended to a variety of robot dolls and toys, which could play music, move and entertain royalty. Progress was made in the 1700s when the term ‘android’ was used to describe an artificial being, and the first automatons which could write and draw were built. Great advancements were made in the 19th century, particularly during the Industrial Revolution, when steam power and extensive automation helped build machines which performed a variety of tasks, transforming the textile manufacturing and transportation industries. Robotics gained immense recognition in the 20th century, considered to be the modern era of the field of robotics. The first theoretical computer called the Turing Machine was conceived. Various forms of robotic arms were developed, capable of lifting, carrying and assembling with precision. The study of Artificial Intelligence became popular in universities like MIT and Stanford, leading to the development of robots which could sense, feel and react to actions. Many of the robots in use today do jobs that are especially difficult for human workers, either requiring great strength or posing grave danger. Robots are used extensively in the medical field, in areas of surgery and disease detection. NASA uses robotic arms on spacecraft, capable of moving large objects, as seen in Figure 2, as well as unmanned robotic spacecraft, reaching great distances in outer space.



//Ms. Mc - excellent overview and figures. Please insert your figures directly below the paragraph in which they are discussed. 10/10//

5/13/2012

Log Entry #9

**Summary of Curiosity's Mission and Instruments** Towards the end of last year, Earth and Mars’ orbits were aligned, an event that only occurs every 2 years. This was the ideal time to launch the rover Curiosity, a robot built by of the Mars Science Laboratory in Florida. Destined to land on Mars in August of this year, the Curiosity rover will roam the surface of Mars for 23 months. Its primary goal is to conduct a comprehensive examination of rocks and other materials on Mars in order to determine if Mars currently supports, has supported, or can support life. Curiosity boasts several modern innovations in robotics. Like its predecessors Spirit and Opportunity, it will feature a six-wheel drive, a rocker-bogie suspension system, and cameras mounted on a mast to aid navigation. However, Curiosity will also feature a far more precise landing system, along with a radioisotope power generator. Scientists plan to communicate with the rover by sending radio signals through previously launched Mars orbiters. As expected, a rover as complicated as Curiosity consists of a multitude of parts. A set of instruments named Sample Analysis at Mars, as seen in Figure 1, will scan samples from both the ground and the atmosphere. An X-ray based instrument called CheMin will also aid the process of examining mineral samples in rocks and soils. The Alpha Particle X-ray Spectrometer, located on the arm, will measure quantities of different elements in the ground. The Mars Hand Lens Imager and the Mast Camera will take pictures of the rover’s surroundings. While the Mast Camera will record high-definition videos, the Mars Hand Lens Imager, located on the arm, will produce extremely detailed pictures of rock, soil, and if present, ice. The Mars Descent Imager will record a high-definition color video of the rover’s landing region. The ChemCam, a device which utilizes laser pulses, vaporizes thin layers of materials from Martian rocks or soil targets from far distances. It will identify compounds based on their reaction to the beam and will take images of the lit area. This process is depicted in Figure 2. The Radiation Assessment Detector measures the radiation present in the Martian atmosphere. After all, a major scientific goal in exploring Mars is determining whether or not Mars is suitable for human life.

In order to measure the atmospheric pressure, temperature, humidity, winds, and ultraviolet radiation levels of Mars, the Rover Environmental Monitoring Station will be deployed. The Dynamic Albedo of Neutrons will detect hydrogen just below the surface of Mars that may indicate ice or water. Finally, a set of equipment, called the Sample Acquisition / Sample Preparation and Handling System, contains an array of tools that will give the rover the capability to scoop up soil, dust rocks, and sort Martian samples.

//Ms. Mc - excellent summary and figures! 10/10//

5/17/2012

Log Entry #10

media type="file" key="pbt_On_The_Edge.AVI" width="446" height="368" Video 1 - On the Edge

Figure 1 - On the Edge Mindstorms Code

This code was used to program the LEGO Mindstorms NXT robot. Each block of the code represents a certain action. (General description of the challenge? -1)

Block 1 – The first block instructs the robot to wait for a sound. The “2” in the upper right corner means that the NXT sound sensor must be attached to port 2 of the NXT robot brick. (What volume of sound? -1/2)

Block 2 – After the robot detects a sound, Block 2 activates, a movement block. It instructs the robot to move forward with servo motors C and B at 50% power for an unlimited amount of time.

Block 3 – Block 3 activates when the ultrasonic sensor, used to measure distance, detects a distance greater than 10 inches. The ultrasonic sensor, attached to port 4, is attached facing downward to the front of the robot.

Block 4 – When the ultrasonic sensor passes over the edge of the table, suddenly, a greater distance is detected. So, Block 4 activates, commanding the robot to stop rotating servo motors C and B. (By braking or coasting? -1/2)

Branching Blocks 5 and 6 – These two blocks activate at once. The upper block instructs the robot to display an image, in this case a stop sign. The lower block instructs the rover to play a prerecorded sound file, in this case saying “Watch out!” (I like the stop sign idea. +1/2). //Ms. Mc - good job! 18.5/20//

6/5/2012

Log Entry #11

An entire field of modern day science is devoted to the exploration of outer space. And recently, scientists have been particularly interested in the possibility of life on Mars. In fact, several recent discoveries support the belief that life does exist on Mars.
 * Part 1**

Firstly, Mars is the most Earth-like planet in the solar system. Although scientists are still unsure of the presence of liquid water on Several orbiters, including the Mars Express orbiter, have detected the presence of water ice and carbon dioxide ice at its poles. Observations from twin rovers Spirit, as seen in Figure 1, and Opportunity indicated the past existence of liquid water on Mars. The Mars Reconnaissance Orbiter observed clay minerals, signs of a war past.



In addition, much research has been conducted here on Earth to solve the question of life of Mars. Recently, we have learned that certain organisms can survive in a very wide range of temperatures. Also, rocks from Mars have found their way to Earth, and scientists have learned from these rocks that in the past, Mars had similar conditions to Earth, and could potentially have started life.

In the future, scientists plan to look for possible fossils from earlier periods in Martian history. However, the possibility still remains that liquid water does exist on Mars.

Microbes are microscopic organisms that have either 1 cell, cell clusters, or more complex cellular systems. There are several types of microbes, including bacteria, fungi, algae, and protozoa. Microbes are made of cells (a bacterial cells is shown in Figure 2). They use minerals and other resources from the environment, are homeostatic, respond to internal and external changes, reproduce, grow, adapt, and respire. So, microbes are living things. Therefore, if a Martian sample contained microbes, I certainly would classify it as alive. (if all 8 characteristics of life were fully functioning. If some were present but not fully functioning, then it would be "dormant." If all 8 were present but none were functioning, then the organism would be dead. If no characteristics or not all 8 were present then it would be nonliving).
 * Part 2**

//Ms. Mc - excellent summary of the evidence of water and possible life on Mars. Left out some detail about how to classify a specimen as living, dead, dormant or non-living. (-1/2). Good figures! 9.5/10//