Std X Science 1 Chapter 10: Space Missions(Satellite launch vehicles , Space missions away from the Earth)

Title : Std X Science 1 Chapter 10: Space Missions

Satellite launch vehicles , Space missions away from the Earth

Maharashtra state board solutions for class 10 SSC board science part STD X-Science 1 Space Missions

 Know everything about; Space Missions .Maharashtra state board class 10 SSC .Get detailed Questions and answers for chapter 10 Science 1, Space missions Satellite launch vehicles , Space missions away from the Earth, part1

 Satellite Launch Vehicles

Q.1) What is a satellite launch vehicle?

Answer: Satellite launch vehicles are used, to place the satellites in their specific orbits. The functioning of the satellite launch vehicle is based on the Newton’s third law of motion. The launch vehicle uses specific type of fuel. The gas produced due to combustion of the fuel expands due to its high temperature and is expelled forcefully through the nozzles at rear side of the launch vehicle. As a reaction of this, a thrust acts on the vehicle, which drives the vehicle high in to the space.

Q.2) How is the structure of the satellite launch vehicle decided?

 Answer: The structure of the launch vehicle is decided by the weight of the satellite and the type of satellite orbit.

 Q.3) How does the fuel effect the satellite launch vehicle?

Answer: The fuel of the vehicle also depends on these factors. The fuel forms a major portion of the total weight of the launch vehicle. Thus, the vehicle has to carry a large weight of the fuel with it. To overcome this problem, launch vehicles with more than one stage are used. Due to this, the weight of the vehicle can be reduced step by step, after its launching.

For example, consider a launch vehicle having two stages. For launching the vehicle, the fuel and engine in the first stage are used. This imparts a specific velocity to the vehicle and takes it to a certain height. Once the fuel in this first stage is exhausted, the empty fuel tank and the engine are detached from the main body of the vehicle and fall either into a sea or on an unpopulated land. As the fuel in the first stage is exhausted, the fuel in the second stage is ignited. However, the vehicle now contains only one (i.e. the second) stage. The weight now being reduced, the vehicle can move with higher speed. Almost all vehicles are made of either two or more stages.

As an example, the structure of a Polar Satellite Launch Vehicle (PSLV) developed by ISRO of India.  Place for satellite Forth stage using liquid fuel Third stage using solid fuel Second stage using liquid fuel First stage using solid fuel Engine using solid fuel which provides the initial thrust

 Q.4) Why does space shuttle return back to earth?

Answer: The launch vehicles are costly, because they can be used only once. USA has, therefore, developed space shuttle which returns to the earth except for the fuel tank and can be reused in multiple launches.

 Q.5) How is rocket used for launch?

 Answer: The ‘rocket’, a type of fire-cracker used in Diwali, is also a sort of launcher. In this rocket, the fuel is ignited using a fuse and the rocket is projected into the sky just like a satellite launcher. Similarly, if a balloon is blown and released with its end open, the air in the balloon is forcefully ejected and the balloon is pushed in opposite direction. This can be explained using the Newton’s third law of motion.

 Space missions away from earth

 Q.1) Why is it necessary to carry out space missions away from the earth?

Answer: artificial satellites are being used for making our life more and more enriched. the telescopes aboard artificial satellites are used to gather information about various objects in the universe. Similarly some Space shuttle Separation of booster rockets Separation of fuel tank Satellite is launched in its orbit and space shuttle returns to earth 14 space missions are used to gain futher knowledge about the universe. In these missions, spacecrafts are sent to the nearby objects in the solar system to observe them more closely. New information has been obtained from such missions and it is helping us to understand the creation and evolution of our solar system

Q.3) How much time will it take for us to reach the moon if we travel with speed of the light? Answer: The astronomical object closest to us is the moon. Light takes 1s to reach from moon to the earth. It means that if we travel with the speed of light, it will take 1s to reach the moon. However, since a spacecraft travels at much smaller speed, it takes longer time to reach the moon. The shortest time taken by a spacecraft to reach the moon, so far,

is 8 hours and 36 minutes. 2GM R ves c = 2 x 6.67 x 10-11x 6 x 1024 6.4 x 106 15

Q.4) Write a note on missions carried out on moon

. Answer: Since the moon is the closest astronomical object to us, the first space missions to objects in the solar system were the missions to the moon. Such missions have so far been executed by USA, Soviet Union, European countries, China, Japan and India. The space crafts in the Luna series sent by Soviet Union reached near the moon. Luna 2, launched in 1959 was first such craft. After that, till 1975, 15 space crafts made chemical analysis of the moon and also measured its gravity, density and radiations. Last four crafts even landed on the moon and brought the samples of stones on the moon for analysis in the laboratories. All these missions were unmanned. America also executed moon missions from 1962 to 1972. The specialty of these missions was that some of these were manned missions. In July, 1969, Neil Armstrong became the first human to step on the moon. In 2008, Indian Space Research Organization (ISRO) successfully launched Chandrayaan- 1 and placed it an into an orbit around the moon. It sent useful information to earth for about a year. The most important discovery made during the mission was the presence of water on the moon surface. India was the first country to discover this.

Q.5) Write a note on mars missions carried out till now.

 Answer: Next to the moon, the astronomical object nearest to the earth is the Mars. Many nations sent space crafts to the Mars. Mars mission is difficult and almost half the missions were unsuccessful. However, ISRO’s performance in this mission is remarkable and we all must be proud of it. The spacecraft ‘Mangalyaan’ made by ISRO using minimum expenses was launched in November, 2013 and was plarced into orbit around the Mars in September, 2014. It obtained very useful information about the surface of the Mars and the atmosphere around it.

 Q.6) Rakesh Sharma

Answer: Rakesh Sharma was the first Indian to travel to space. He went into space along with two Russian astronauts under the joint Indo - USSR space programme. He stayed in space for 8 days.

 Q.7) Kalpana Chawla

Answer: Kalpana Chawla obtained her Engineering in Aeronautics degree from Punjab and in 1988 obtained her doctorate from University of Colorado. She was in space for 336 hrs during research mission. While returning to earth from space, on 1st February, 2003, the Columbia space craft exploded and Kalpana perished.

 Q.8) Sunita Williams

 Answer: Sunita Williams travelled to the international space station in space shuttle Discovery in 2006. She worked for 29 hrs outside the space station. She created a record by staying for 192 days in space.

 Q.9) Write a note on missions carried out to other planets.

Answer: Many missions have been executed to study other planets also. In some of these missions the space crafts orbited the planets, some landed on the planets and some just passed near the planet and observed them. Additionally, spacecrafts have been sent to observe asteroids and comets and they have successfully collected some dust and stones from the asteroids and brought them back on the earth. We are getting very useful information from all these missions clarifying our concepts about the origin and evolution of the solar system.

Q.10) Discuss about India and space technology.

 Answer: India also has made remarkable progress in the science and technology of launch vehicles. Various types of launch vehicles have been developed to put satellites having weight upto 2500 kg, into all types of orbits. PSLV and GSLV are two important launchers. The scientific and technological feats achieved by India in this field have a significant contribution to the national and social development. INSAT and GSAT satellite series is actively working in the field of telecommunication, television broadcasting and meteorological services. Availability of television, telephone and internet services all over the nation has been possible due to these satellites only. EDUSAT satellite in this series is used specially in the field of education. IRS satellite series is working for monitoring and management of natural resources and disaster management. To exactly locate position of any place on the earth’s surface in terms of its precise latitude and longitude, the IRNSS satellite series has been established.

 Q.11) Dr. Vikram Sarabhai

 Answer: Vikram Sarabhai is considered as the father of Indian space program. His efforts led to foundation of Physical Research Laboratory (PRL) at Ahmedabad. In 1962, Indian government constituted ‘Indian National Committee for Space Research’ under his Chairmanship and first satellite launch center was established at Thumba in 1963. The launching of India’s first satellite ‘Aryabhatta’ into the space, was the result of his efforts. He played an important role in the establishment of Indian Space Research Organization (ISRO).

 Q.12) What is space debris?

Answer: In addition to the artificial satellite, some other objects are also revolving around the earth. It includes, non-functional satellites, parts of the launcher detached during launching and debris generated due to collision of satellite with other satellite or any other object in the space. According to one estimation made in 2016, there are about 2 crore pieces of length more than 1 cm, revolving around the earth! All this is nothing but the debris in space.

Q.13) What problems does the space debris cause?

Answer: This debris can be harmful to the artificial satellites. It can collide with these satellites or space crafts and damage them. This debris is increasing day by day. Soon, it will be difficult to launch new spacecrafts. It is, therefore, very essential to manage the debris. Some studies and experiments are being done with this in view. Hope that soon we will have a solution for this problem and the future satellites and spacecrafts will not be in danger any more

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