Download - Mission to mars

Transcript
Page 1: Mission to mars

Diane Guo Mission to Mars Grade 10 Science

Mission To Mars

Building a Space Shuttle

Figure 1: Labeled diagram of space shuttle

There are several reasons I chose this design, from the shape, mass and functions. Figure 1 is

the spaces shuttle I have designed. I designed my space shuttle in a cone shape, because cone

shape will reduce the resistance force on the space shuttle. There are two wheels under the

space shuttle, they are used for the landing of the space shuttle. There is a rudder at the end of

the space shuttle, it is used as a speed brake when it breaks through the atmosphere and tries

to 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 a

space shuttle, it is a material that is hard to bend or deform. When going through the atmos-

phere, titanium can help protecting the space shuttle. 1The speed brake will increase drag

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 parachute when its

is at around 10 kilometers above the earth, which is around the troposphere, because then the

1 http://en.allexperts.com/q/Metals-2415/stongest-metal-1.htm

1

Page 2: Mission to mars

Diane Guo Mission to Mars Grade 10 Science space shuttle will have enough time to decelerate. Usually an empty space shuttle would

weight around 74,843 kg, but with solid rocket boosters and all the fuels it weights around 4

million pounds (2 million kg), and has a velocity around 17,500 miles per hour (27,359km per

hour). The momentum of the space shuttle will be p= mv, which is 2,000,000 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 reacting

on it. I will use Newton’s 2nd law F=ma to calculate the weight force. Fw=mg= 2,000,000 x

9.81=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 two

solid rocket boosters are used to provide most of the force that is needed to bring the space

shuttle off the launch pad. The 2 solid rocket boosters provide about 70% of the force, while

the engines provide the rest 30%. 2

Usually, when a person cough, it produces a g force of 3.5 g; a rollar coaster has a g force of

6.7g.3 An astronaut in orbit experience 0 g, because there is no gravity in space, it is called

weightlessness. Weightlessness occurs when there is no force of support or acceleration on

your body.

2 http://science.howstuffworks.com/space-shuttle.htm

3 http://www.wisegeek.com/what-is-g-force.htm

2

Page 3: Mission to mars

Diane Guo Mission to Mars Grade 10 Science Launching your Rocket

Figure 2: Labeled diagram of the rocket Figure 3: Launching of a rocket

As shown in Figure 3, first the computers takes over control of the rocket and the space shut-

tle, then the shuttle’s engine ignite one by one. The solid rocket boosters will ignite and lifts

the entire space shuttle off the pad. At around 1 minute time, the engines are at their best po-

sition to work. At around two minutes, the solid rocket boosters separate from the orbiter,

parachutes that are attached to them will deploy, falling into the ocean nearby. At around 8.5

minutes the fuels inside the external tank will be burn out. The External Tank separates from

the space shuttle, burns off itself, and the three engines push the space shuttle into orbit.4 The

fuel I will be using for the engine is monomethyl hydrazine. Because when the two substances

combined together, they light up and start to burn automatically, it is because there is no oxy-

gen mixed with the two substances. Most importantly, when they burn, no sparks will be pro-

duces, that way the safety of the astronauts will be better. If there is sparks when the fuel is

burned, there will be chances that the sparks will lead to serious explosion with the fuel. Oxi-

dizer will also be needed, it will be kept separately with the fuel in two different tanks. Helium

will help to push the fuels through pipes that connect to the engine. The reason why helium is

4 http://science.howstuffworks.com/space-shuttle.htm

3

Page 4: Mission to mars

Diane Guo Mission to Mars Grade 10 Science been used is because it is a natural gas that would not burn, this increases the safety of the as-

tronauts. 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 su-

port the space shuttle and the engine to its orbit.

Fig-

ure 5:

par-

allel forces acting on a

plane to keep it straight.

Figure 4: Free body diagram of the space shuttle

Overcoming Problems during the journey

Because Earth is third from the sun and mars is the forth, the Earth revolves faster than Mars

around the sun, so the distance between Earth and Mars is varied from 54.6 million km up to

225 million km.5 The average distance between Earth and Mars is about 225 million km. IF we

assume the speed of the space shuttle is 28,000 km per hour (672,000 km per day), then it

will take 333 days just to reach mars! Therefore, I will launch the rocket when the Earth is

closest to Mars, which is around 55 million km far. If the distance is only 55 million km, the

time it takes to reach mars will be reduced to 82 days. So the whole journey of mission to

mars 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 is

something that everything on Earth has. Newton’s law of universal gravitation stated that ev-

5 http://www.space.com/14729-spacekids-distance-earth-mars.html

4

This diagram helps to explain Newton’s third law, “For every action there is an equal and opposite reaction.” The space shuttle has a weight force of 2,000,000 Newtons, and thrusters to help the space shuttle to lift off. The resultant force is the force that is reacted back to te rocket and therefore it will rise up to the sky.

Page 5: Mission to mars

Diane Guo Mission to Mars Grade 10 Science ery point mass in the universe attracts every other point mass with a force that is directly pro-

portional to the product of their masses and inversely proportional to the square of the dis-

tance between them.

The space shuttle is a completely different environment from the earth, therefore the astro-

nauts will be facing a lot of problems during their mission to mars. First of all, the air in the

space shuttle must be similar to Earth, so that the astronauts can breathe properly. In order to

do that the orbiter will be carrying liquid oxygen and liquid nitrogen along with the space

shuttle. Another major problem is water. Water will be made from liquid oxygen and hydro-

gen in the fuel cells, where it turns the fuels into water.6 The food that the astronauts eat are

in several forms: dehydrated, low moisture, heat-stabilized, irradiated and fresh.7 Inside 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 won’t bring many fresh food, because they will

not last very long, and will take up the limited space in the food cabin. I will be sending 2 as-

tronauts into the space, if we assume 1 astronaut eat 100 g for each dish, and 4 different

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 into space for 2

people to eat during the 162 days. The excrete that will be create, will just simply go out to

space. The astronauts will wear a bag inside their space suit, the bag will have a tube that is

connected to a machine that will eliminate all the waste into the space. One every important

thing for the astronauts to do is to exercise. It is because they are trapped in a small area for a

very long time with out moving a lot, their muscle will get weaker than they were on Earth.

Therefore, I will have fitness equipments on the space shuttle, so that the astronauts can exer-

cise as much as they can to reduce the weaken of their muscle. If any outside part of the space

shuttle breaks, the astronaut will go out and fix it with a safety tether. It will hold the astro-

naut onto the space shuttle. They will also use cloth tethers when the astronauts need to use

both their hands to fix the space shuttle. If te tether breaks, the astronaut can use the air bag

at the back of their space suit to get back to the space shuttle.

6 http://science.howstuffworks.com/space-shuttle.htm

7 Ibid

5

Page 6: Mission to mars

Diane Guo Mission to Mars Grade 10 Science Landing on Mars

Figure 6: La-

beled diagram of Mars lander

After 81 days of flying, the space shuttle will reach the surface of Mars. Figure 6 is a diagram

that shows the Mars lander coming out from the space shuttle. The Mars lander is also a cone

shape, because it has to fit into the head of the space shuttle. When the space shuttle is getting

close to Mars, the gear on the space shuttle will open and the Mars lander will come out. The

red region in the diagram is where the fuels will be, the fuel is for getting out of the space

shuttle and getting back. While the lander stays on Mars, the space shuttle will stay put near

by Mars, so that when the time is up, the lander can easily get back to it. Because the space

shuttle is moving at a great speed, it has to decelerate before landing on Mars. It will start to

decelerate around 5000 km away from Mars, so by the time it is near to Mars it can be

stopped easily. The gravity on Mars is 38% of Earth8, so the space shuttle will weigh around

77,000 x 0.38 = 29,260 kg on mars. (The space shuttle’s weight changed from 2,000,000 kg to

77,000 kg because the rockets and the external tank were dropped off before going into

space) The momentum of the space shuttle will therefore just be 29,260 kgm/s because it

won’t be moving on Mars.

8 http://www.universetoday.com/22603/mars-compared-to-earth/

6

Page 7: Mission to mars

Diane Guo Mission to Mars Grade 10 Science

Re-launching your Shuttle to return to Earth

To get back from Mars to Earth, the space shuttle will first communicate with the ground. The

way is to send a digital signal from the space shuttle back to Earth. The advantage of using

digital signals is that numbers, letters, sounds, images can also be send back to Earth.9 Also,

digital signals does not cause errors to the information, and the information can be copied as

many times as you want. When the space shuttle is about 225 km away from Earth, the speed

will be 3000 km/h.10 When it is 40 km away from the runway, the speed will decrease to 1000

km/h.11 When the space shuttle is 610 meters above the Earth,12 the astronaut will release the

parachute and the speed brake, they will help the space shuttle slow down by creating air re-

sistance.

9 http://www.diffen.com/difference/Analog_vs_Digital

10 http://wiki.answers.com/Q/How_does_a_space_shuttle_come_back_to_earth

11 Ibid

12 Ibid

7

Page 8: Mission to mars

Diane Guo Mission to Mars Grade 10 Science

Source

Category. "Metals: the stongest metal, precious metals, space shuttle."AllExperts Questions

& Answers.10 Nov. 2012. http://en.allexperts.com/q/Metals-2415/stongest-metal-1.htm

Fraser Cain"Mars Compared to Earth." Universe Today — Space and astronomy

news. 13 Nov. 2012. http://www.universetoday.com/22603/mars-compared-to-earth/

Freudenrich, Craig, and Ph.D.. "HowStuffWorks "How Space Shuttles Work"." HowStuff-

Works "Science".9 Nov. 2012.http://science.howstuffworks.com/space-shuttle.htm

Unknown. "Analog vs Digital - Difference and Comparison | Diffen." Diffen - Compare Any-thing. Diffen. Discern. Decide.13 Nov. 2012.http://www.diffen.com/difference/Analog_vs_Digital

Unknown. " 8 Surprising Space Shuttle Facts | NASA Space Shuttle Trivia & Facts | Final

Shuttle Missions & Shuttle Program | Space.com ." Space and NASA News – Universe

and Deep Space Information | Space.com .13 Nov. 2012.

http://www.space.com/12127-8-surprising-space-shuttle-facts.html

Unknown. “Feeling weightless when you go over the hump”. 10 Nov. 2012

http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/hump.html

Unknown."NASA - Shuttle Basics." NASA - Home. 8 Nov. 2012.

http://www.nasa.gov/returntoflight/system/system_STS.html

Unknown. "NASA - Sunita Williams' Frequently Asked Questions:." NASA - Home. 13 Nov.

2012.http://www.nasa.gov/mission_pages/station/expeditions/expedition15/

Williams_FAQ_6.html

Unknown."Overall Shuttle Specifications."Columbia's Sacrifice. 18 Nov. 2012.

http://www.columbiassacrifice.com/&0_shttlovrvw.htm

8

Page 9: Mission to mars

Diane Guo Mission to Mars Grade 10 Science Unknown. “Space Food”. NASA.11 Nov. 2012

http://spaceflight.nasa.gov/living/spacefood/index.html

Unknown. "What is G-Force?." wiseGEEK: clear answers for common questions.10

Nov. 2012. http://www.wisegeek.com/what-is-g-force.htm

Unknown. "What Is the Distance Between Earth and Mars? | Space.com ." Space and NASA

News – Universe and Deep Space Information | Space.com . 13 Nov. 2012.

http://www.space.com/14729-spacekids-distance-earth-mars.html

9