Mission to mars

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  • 1. Diane GuoMission to MarsGrade 10 ScienceMission To MarsBuilding a Space ShuttleFigure 1: Labeled diagram of space shuttleThere are several reasons I chose this design, from the shape, mass and functions. Figure 1 isthe spaces shuttle I have designed. I designed my space shuttle in a cone shape, because coneshape will reduce the resistance force on the space shuttle. There are two wheels under thespace shuttle, they are used for the landing of the space shuttle. There is a rudder at the end ofthe space shuttle, it is used as a speed brake when it breaks through the atmosphere and triesto land.The space shuttle will be made with titanium on the outside layer of the space shuttle.Titanium is widely used for military uses and aeronautical uses. Titanium is hard enough for aspace shuttle, it is a material that is hard to bend or deform. When going through theatmosphere, titanium can help protecting the space shuttle. 1The speed brake will increasedrag once it starts to work, the top and bottom half split open to increase air resistance,therefore decrease the speed of the space shuttle. Aslo, to reduce speed, I will use a parachutewhen its is at around 10 kilometers above the earth, which is around the troposphere,1 http://en.allexperts.com/q/Metals-2415/stongest-metal-1.htm1

2. Diane GuoMission to MarsGrade 10 Sciencebecause then the space shuttle will have enough time to decelerate. Usually an empty spaceshuttle would weight around 74,843 kg, but with solid rocket boosters and all the fuels itweights around 4 million pounds (2 million kg), and has a velocity around 17,500 miles perhour (27,359km per hour). The momentum of the space shuttle will be p= mv, which is2,000,000 x 8 =16,000,000 kg m/s.The space shuttle is very heavy, so at the same time there will be a lot of weight force reactingon it. I will use Newtons 2nd law F=ma to calculate the weight force. Fw=mg= 2,000,000 x9.81=1.962x10^7 (N)Although the space shuttle weight a lot, however there are ways to overcome the weight force.I will have two solid rocket boosters, and 3 engines to help bring up the space shuttle. The twosolid rocket boosters are used to provide most of the force that is needed to bring the spaceshuttle off the launch pad. The 2 solid rocket boosters provide about 70% of the force, whilethe engines provide the rest 30%. 2Usually, when a person cough, it produces a g force of 3.5 g; a rollar coaster has a g force of6.7g.3 An astronaut in orbit experience 0 g, because there is no gravity in space, it is calledweightlessness. Weightlessness occurs when there is no force of support or acceleration onyour body.2 http://science.howstuffworks.com/space-shuttle.htm3 http://www.wisegeek.com/what-is-g-force.htm2 3. Diane GuoMission to MarsGrade 10 ScienceLaunching your RocketFigure 2: Labeled diagram of the rocket Figure 3: Launching of a rocket As shown in Figure 3, first the computerstakes over control of the rocket and the space shuttle, then the shuttles engine ignite one byone. The solid rocket boosters will ignite and lifts the entire space shuttle off the pad. Ataround 1 minute time, the engines are at their best position to work. At around two minutes,the solid rocket boosters separate from the orbiter, parachutes that are attached to them willdeploy, falling into the ocean nearby. At around 8.5 minutes the fuels inside the external tankwill be burn out. The External Tank separates from the space shuttle, burns off itself, and thethree engines push the space shuttle into orbit.4 The fuel I will be using for the engine ismonomethyl hydrazine. Because when the two substances combined together, they light upand start to burn automatically, it is because there is no oxygen mixed with the twosubstances. Most importantly, when they burn, no sparks will be produces, that way the safetyof the astronauts will be better. If there is sparks when the fuel is burned, there will bechances that the sparks will lead to serious explosion with the fuel. Oxidizer will also beneeded, it will be kept separately with the fuel in two different tanks. Helium will help to pushthe fuels through pipes that connect to the engine. The reason why helium is been used is4 http://science.howstuffworks.com/space-shuttle.htm 3 4. Diane GuoMission to MarsGrade 10 Sciencebecause it is a natural gas that would not burn, this increases the safety of the astronauts.Each solid rocket booster carries more than 1 million pounds (45,359 kg) of solid propellant,and the external tank carries more than 500,000 gallons of fuel. They together suport thespace shuttle and the engine to its orbit.This diagram helps to explainNewtons third law, For everyaction there is an equal andopposite reaction. The spaceshuttle has a weight force of2,000,000 Newtons, and thrustersto help the space shuttle to lift off.The resultant force is the force thatis reacted back to te rocket andtherefore it will rise up to the sky. Figure 5: parallel forcesacting on a plane to keep it straight. Figure 4: Free body diagram of the space shuttleOvercoming Problems during the journeyBecause Earth is third from the sun and mars is the forth, the Earth revolves faster than Marsaround the sun, so the distance between Earth and Mars is varied from 54.6 million km up to225 million km.5 The average distance between Earth and Mars is about 225 million km. IF weassume the speed of the space shuttle is 28,000 km per hour (672,000 km per day), then itwill take 333 days just to reach mars! Therefore, I will launch the rocket when the Earth isclosest to Mars, which is around 55 million km far. If the distance is only 55 million km, thetime it takes to reach mars will be reduced to 82 days. So the whole journey of mission tomars will take approximately 164 days, about 5 and half month.Gravitational force is the reason that causes the Earth and Mars orbit around the sun, it issomething that everything on Earth has. Newtons law of universal gravitation stated that5 http://www.space.com/14729-spacekids-distance-earth-mars.html4 5. Diane GuoMission to MarsGrade 10 Scienceevery point mass in the universe attracts every other point mass with a force that is directlyproportional to the product of their masses and inversely proportional to the square of thedistance between them.The space shuttle is a completely different environment from the earth, therefore theastronauts will be facing a lot of problems during their mission to mars. First of all, the air inthe space shuttle must be similar to Earth, so that the astronauts can breathe properly. Inorder to do that the orbiter will be carrying liquid oxygen and liquid nitrogen along with thespace shuttle. Another major problem is water. Water will be made from liquid oxygen andhydrogen in the fuel cells, where it turns the fuels into water. 6 The food that the astronautseat are in several forms: dehydrated, low moisture, heat-stabilized, irradiated and fresh. 7Inside the space shuttle there will be a cabin for food supplies and refreshment equipments.Because the space shuttle is leaving Earth for 162 days, so I wont bring many fresh food,because they will not last very long, and will take up the limited space in the food cabin. I willbe sending 2 astronauts into the space, if we assume 1 astronaut eat 100 g for each dish, and 4different dishes are provided for each meal. 3 x 400 = 1200g (per day) 1200 x 162= 194,400 g 194kg . 194 x 2= 388 kg The space shuttle will bring approximately 400 kg of food intospace for 2 people to eat during the 162 days. The excrete that will be create, will just simplygo out to space. The astronauts will wear a bag inside their space suit, the bag will have a tubethat is connected to a machine that will eliminate all the waste into the space. One everyimportant thing for the astronauts to do is to exercise. It is because they are trapped in a smallarea for a very long time with out moving a lot, their muscle will get weaker than they were onEarth. Therefore, I will have fitness equipments on the space shuttle, so that the astronautscan exercise as much as they can to reduce the weaken of their muscle. If any outside part ofthe space shuttle breaks, the astronaut will go out and fix it with a safety tether. It will holdthe astronaut onto the space shuttle. They will also use cloth tethers when the astronautsneed to use both their hands to fix the space shuttle. If te tether breaks, the astronaut can usethe air bag at the back of their space suit to get back to the space shuttle.Landing on Mars6 http://science.howstuffworks.com/space-shuttle.htm7 Ibid 5 6. Diane GuoMission to MarsGrade 10 ScienceFigure 6: Labeled diagramof MarslanderAfter 81 days of flying, the space shuttle will reach the surface of Mars. Figure 6 is a diagramthat shows the Mars lander coming out from the space shuttle. The Mars lander is also a coneshape, because it has to fit into the head of the space shuttle. When the space shuttle is gettingclose to Mars, the gear on the space shuttle will open and the Mars lander will come out. Thered region in the diagram is where the fuels will be, the fuel is for getting out of the spaceshuttle and getting back. While the lander stays on Mars, the space shuttle will stay put nearby Mars, so that when the time is up, the lander can easily get back to it. Because the spaceshuttle is moving at a great speed, it has to decelerate before landing on Mars. It will start todecelerate around 5000 km away from Mars, so by the time it is near to Mars it can bestopped easily. The gravity on Mars is 38% of Earth8, so the space shuttle will weigh around77,000 x 0.38 = 29,260 kg on mars. (The space shuttles weight changed from 2,000,000 kg to77,000 kg because the rockets and the external tank were dropped off before going intospace) The momentum of the space shuttle will therefore just be 29,260 kgm/s because itwont be moving on Mars.8 http://www.universetoday.com/22603/mars-compared-to-earth/6 7. Diane GuoMission to MarsGrade 10