Objective
The objective of ISRO (Indian Research Space Organization) is to develop space technology and its application to various national tasks. Accordingly Indian Research Space Organization(ISRO) has successfully operationalised two major sattelite systems namely Indian national Sattelites(INSAT) for communication services and Indian Remote Sensing(IRS) sattelites for management for natural resources; also, Polar Sattelite Launch Vehicle(PSLV) for launching IRS type of sattelite and Geostationary Sattelite Launch Vehicle(GSLV) for INSAT type of sattelites.
1. Introduction to Chandrayaan-1
Chandrayaan-1, India’s first scientific mission to Moon is slated for launch during 2007.
The primary objectives of the mission are to expand the scientific knowledge about the origin and evolution of moon, upgrade India’s technological capabilities and provide challenging opportunities to the young scientists working in planetary sciences.
The primary objectives of the mission are to expand the scientific knowledge about the origin and evolution of moon, upgrade India’s technological capabilities and provide challenging opportunities to the young scientists working in planetary sciences.
Pursuit of space science is one of the important objectives of the Indian Space Programme. The Thumba Equatorial Rocket Launching Station (TERLS) was established near Thiruvananthapuram in 1963 for studying the ionospheric electrojet and related phenomenon, which paved the way for space research activities in the country. Also, the first Indian satellite, Aryabhata, launched in 1975, carried scientific experiments to investigate X-ray astronomy, Solar neutrons and supra thermal electron density. Since then, several instruments for scientific research have been flown on board high altitude balloons, sounding rockets and satellites. Several ground based facilities have also been set up for conducting research by scientists from universities and research institutions in astrophysical, solar and atmospheric research programmes.
India has vast experience in developing and launching operational spacecraft systems for survey and management of natural resources, meteorological services and satellite communication. The technologies developed and available now at ISRO can be fully exploited for embarking on planetary missions with well thought out scientific objectives. The Polar Satellite Launch Vehicle (PSLV) is capable of undertaking missions to moon and other terrestrial planets.
The idea of undertaking a scientific mission to Moon was mooted by the Indian Academy of Sciences. It was further discussed by the Astronautical Society of India. Based on recommendations of the scientific community and as a first major initiative, a National Lunar Mission Task Force was constituted by ISRO with leading scientists and technologists from all over the country for considering and making an assessment of the possible configuration and feasibility of taking up an Indian Moon Mission. The task team conducted a feasibility study and recommended the Indian lunar mission detailing scientific objectives, instruments to be flown, launch and spacecraft technologies that are available and those to be developed, setting up of a Deep Space Network (DSN) station for communication between lunar craft and earth and budgetary aspects.
The Study Report of the Task Team was reviewed in April 2003 by a peer group of about 100 eminent scientists from various relevant fields of planetary & space physics, earth sciences, geology, physics, astronomy and cosmology. After detailed discussions, the participants unanimously recommended that India should undertake the Moon Mission.
The recommendations are summarized as follows:
2. Scientific Objectives
Chandrayaan-1 is aimed at chemical, mineralogical and photo-geologic mapping of the moon in visible, near infrared, low energy and high energy X-rays with high spatial resolution. Specifically, the objectives will be to carry out high-resolution three-dimensional mapping of topographic features along with the simultaneous mapping of distribution of minerals such as Si, Al, Mg, Ca, Ilmenites (FeTiO3, which may retain 3He) and elemental chemical species including radioactive nuclides. This mapping could unravel the mysteries about the origin and evolution of the planetary system in general and moon-earth system in particular. The instruments that will be used for the mapping are:
3. About Moon
Looming at about 384,400 km from the Earth, the Moon is the brightest object in the night sky and only second in brightness to that of the Sun. It has a diameter of 3,476 km and a mass of 7.35x1022 kg with a mean density of only 3.35 g/cc as compared to 5.52 g/cc of that of Earth. It has no atmosphere and degassing from the surface produces only trace gases. The gravitational force on the Moon is only 1/6th of that of Earth, and is not able to retain its atmosphere. The Moon does not have a substantial core of molten iron like Earth and hence has no magnetic field. The Moon undergoes extremes in temperature - it is scorching heat at 110º C during the day and freezing cold at -180º C during night.
An eclipse occurs at those times when the Moon moves into a position of direct alignment with the Sun and the Earth. A solar eclipse can occur only at New Moon when the Moon passes between Earth and Sun.
If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or eclipsed by the Moon. Whereas lunar eclipse occurs when the Sun and the Moon are on opposite sides of the Earth and the full Moon passes through the shadow of the Earth. The solar and lunar eclipses are truly spectacular celestial phenomenon.
The low and high tides due to the gravitational effects of Sun and the Moon are well known phenomena affecting day-to-day life.
An interesting fact is that the Moon's rotation period around its axis and revolution period around the Earth takes the same time of about 27 days and hence the same side of Moon is permanently facing the Earth. The time taken from one new Moon to another new Moon (synodic period) is about 29 days.
So far there has been no indication of life existing on Moon. The Moon's surface is generally dry, dusty and rocky. The rocky crust is about 60 km thick on the near side that faces the Earth and about 107 km on the far side. Moon's terrain is divided into two sharply contrasting areas - the rugged and very ancient mountainous - Highlands regions and smooth younger lowland Maria regions.
While Earth's mountain ranges are formed by movements and coming closer of crust sections pushing against each other (known as plate tectonics), the lunar highlands did not result from an active uplifting process due to crustal dynamics. But its surface has been periodically bombarded with different sizes of meteorites and asteroids. During the initial period of lunar evolution, such giant meteor impacts resulted in the creation of flatlands or lunar basins. The regions not affected by these giant impacts are the lunar highlands.
Ancient observers thought that the round and dark areas on the face of the Moon are seas, which they called Maria (Latin word for seas). Maria are not seas at all but relatively flat areas produced by massive flow of lava from earlier period of lunar volcanism.Maria comprises 16 percent of the Moon's surface and has huge impact basins. They are concentrated in the near side of the Moon. Associated with the Lunar Maria are gravity anomalies called mascons (mass concentrations). A spacecraft would accelerate as it nears the Maria region and decelerate as it move away due to such gravitational anomalies.
The Moon is covered with a gently rolling layer of powdery soil and rock fragments called the regolith, which is made of debriscreated by the meteor impacts forming the craters. Such craters are the remains of collisions between an asteroid, comet or meteorite and the Moon. The size, mass, speed and angle of the falling object determine the size, shape and complexity of resulting craters. Surface of the Moon is scarred with millions of impact craters and the record has been retained on Moon's surface.
One striking difference between the lunar surface material and that of Earth concerns the most common kinds of rocks. On the Earth the most common rocks are sedimentary because of atmospheric and water erosion of the surface. On the Moon there is no atmosphere and little or no water, and the most common kind of rock is igneous (fire-formed-rocks).According to studies, North Polar Region (Courtesy: NASA) the lunar surface material has the following geological characteristics:
4. Origin of Moon
The origin of the Moon is still not clearly understood and there have been speculations about its origin how it was formed and how it acquired its present orbit around the Earth. Studies using the chemical, mineralogical, isotopic and chronological data led to postulation of five major theories on the origin of the Moon:
The Fission Theory:At some time in the distant past, the Moon had separated from the Earth. Perhaps the Earth was not as round then as it is today and that imbalance caused it to split in two.
The Capture Theory:
The Moon was formed somewhere in the solar system and was later captured by the gravitational field of the Earth.
The Co-accretion Theory:
The Earth and Moon may have been formed at the same time from solar nebula by co-accretion.The Colliding Planetesimal Theory: Moon condensed from the debris of the interaction of Earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the solar system.
The Giant Impact Theory:
A planetesimal of Mars size had impact with the Earth, early in its history, ejecting large volume of matter from the evolving Earth, which aggregated and formed the Moon.
5. Early Interest
Through the ages Moon has been the heavenly body, which sparked the imagination of mankind more than the planets in our solar system. In the distant past our ancestors looked up to the sky with awe and wonder. At the beginning of recorded history, the passage of time was decided by observing the positions and phases of the Moon. The idea that the Moon was not perfectly smooth can be traced back to 450 B.C. At approximately the same time the Greek astronomer, Hipparchus, using observations and mathematical formulae measured the distance to the Moon as well as the Sun with surprising accuracies. In the Vedic period (1500-500 B.C.), Indian astronomers had determined the orbit of the Moon precisely and based on the phases of the Moon, developed the lunar calendar which is used even now. The Indian astronomer Aryabhata (~500 A.D), after whom the first Indian satellite was named, was one of the early scholars who determined the Moon’s size and distance accurately.
India has vast experience in developing and launching operational spacecraft systems for survey and management of natural resources, meteorological services and satellite communication. The technologies developed and available now at ISRO can be fully exploited for embarking on planetary missions with well thought out scientific objectives. The Polar Satellite Launch Vehicle (PSLV) is capable of undertaking missions to moon and other terrestrial planets.
The idea of undertaking a scientific mission to Moon was mooted by the Indian Academy of Sciences. It was further discussed by the Astronautical Society of India. Based on recommendations of the scientific community and as a first major initiative, a National Lunar Mission Task Force was constituted by ISRO with leading scientists and technologists from all over the country for considering and making an assessment of the possible configuration and feasibility of taking up an Indian Moon Mission. The task team conducted a feasibility study and recommended the Indian lunar mission detailing scientific objectives, instruments to be flown, launch and spacecraft technologies that are available and those to be developed, setting up of a Deep Space Network (DSN) station for communication between lunar craft and earth and budgetary aspects.
The Study Report of the Task Team was reviewed in April 2003 by a peer group of about 100 eminent scientists from various relevant fields of planetary & space physics, earth sciences, geology, physics, astronomy and cosmology. After detailed discussions, the participants unanimously recommended that India should undertake the Moon Mission.
The recommendations are summarized as follows:
- The Indian Moon Mission assumes significance in the context of the international scientific community considering several exciting missions in planetary exploration, in the new millennium.
- ISRO has the necessary expertise to develop and launch the Moon Mission with imaginative features and it would be different from the past missions. Hence ISRO should go ahead with the project approval and implementation.
- Apart from technological and scientific gains, it would provide the needed thrust to basic science and engineering research in the country. The project would help return of young talents to the arena of fundamental research.
- The Academia, in particular, the university scientists would find participation in such a project intellectually rewarding. In this context, the scientific objectives would need further refinement to include other innovative ideas from a broader scientific community through Announcement of Opportunity, etc.
2. Scientific Objectives
Chandrayaan-1 is aimed at chemical, mineralogical and photo-geologic mapping of the moon in visible, near infrared, low energy and high energy X-rays with high spatial resolution. Specifically, the objectives will be to carry out high-resolution three-dimensional mapping of topographic features along with the simultaneous mapping of distribution of minerals such as Si, Al, Mg, Ca, Ilmenites (FeTiO3, which may retain 3He) and elemental chemical species including radioactive nuclides. This mapping could unravel the mysteries about the origin and evolution of the planetary system in general and moon-earth system in particular. The instruments that will be used for the mapping are:
- Terrain Mapping stereo Camera (TMC)
- Hyper Spectral Imager (HySI)
- Lunar Laser Ranging Instrument (LLRI)
- Collimated Low Energy X-ray spectrometer (LEX)
- Solar X-ray Monitor (SXM)
- High Energy X-ray/g-ray spectrometer (HEX)
3. About Moon
Looming at about 384,400 km from the Earth, the Moon is the brightest object in the night sky and only second in brightness to that of the Sun. It has a diameter of 3,476 km and a mass of 7.35x1022 kg with a mean density of only 3.35 g/cc as compared to 5.52 g/cc of that of Earth. It has no atmosphere and degassing from the surface produces only trace gases. The gravitational force on the Moon is only 1/6th of that of Earth, and is not able to retain its atmosphere. The Moon does not have a substantial core of molten iron like Earth and hence has no magnetic field. The Moon undergoes extremes in temperature - it is scorching heat at 110º C during the day and freezing cold at -180º C during night.
An eclipse occurs at those times when the Moon moves into a position of direct alignment with the Sun and the Earth. A solar eclipse can occur only at New Moon when the Moon passes between Earth and Sun.
If the Moon's shadow happens to fall upon Earth's surface at that time, we see some portion of the Sun's disk covered or eclipsed by the Moon. Whereas lunar eclipse occurs when the Sun and the Moon are on opposite sides of the Earth and the full Moon passes through the shadow of the Earth. The solar and lunar eclipses are truly spectacular celestial phenomenon.
The low and high tides due to the gravitational effects of Sun and the Moon are well known phenomena affecting day-to-day life.
An interesting fact is that the Moon's rotation period around its axis and revolution period around the Earth takes the same time of about 27 days and hence the same side of Moon is permanently facing the Earth. The time taken from one new Moon to another new Moon (synodic period) is about 29 days.
So far there has been no indication of life existing on Moon. The Moon's surface is generally dry, dusty and rocky. The rocky crust is about 60 km thick on the near side that faces the Earth and about 107 km on the far side. Moon's terrain is divided into two sharply contrasting areas - the rugged and very ancient mountainous - Highlands regions and smooth younger lowland Maria regions.
While Earth's mountain ranges are formed by movements and coming closer of crust sections pushing against each other (known as plate tectonics), the lunar highlands did not result from an active uplifting process due to crustal dynamics. But its surface has been periodically bombarded with different sizes of meteorites and asteroids. During the initial period of lunar evolution, such giant meteor impacts resulted in the creation of flatlands or lunar basins. The regions not affected by these giant impacts are the lunar highlands.
Ancient observers thought that the round and dark areas on the face of the Moon are seas, which they called Maria (Latin word for seas). Maria are not seas at all but relatively flat areas produced by massive flow of lava from earlier period of lunar volcanism.Maria comprises 16 percent of the Moon's surface and has huge impact basins. They are concentrated in the near side of the Moon. Associated with the Lunar Maria are gravity anomalies called mascons (mass concentrations). A spacecraft would accelerate as it nears the Maria region and decelerate as it move away due to such gravitational anomalies.
The Moon is covered with a gently rolling layer of powdery soil and rock fragments called the regolith, which is made of debriscreated by the meteor impacts forming the craters. Such craters are the remains of collisions between an asteroid, comet or meteorite and the Moon. The size, mass, speed and angle of the falling object determine the size, shape and complexity of resulting craters. Surface of the Moon is scarred with millions of impact craters and the record has been retained on Moon's surface.
One striking difference between the lunar surface material and that of Earth concerns the most common kinds of rocks. On the Earth the most common rocks are sedimentary because of atmospheric and water erosion of the surface. On the Moon there is no atmosphere and little or no water, and the most common kind of rock is igneous (fire-formed-rocks).According to studies, North Polar Region (Courtesy: NASA) the lunar surface material has the following geological characteristics:
- The Maria are mostly composed of dark basalts which are formed from rapid cooling of molten rocks from massive lava flows.
- The Highlands rocks are largely Anorthosite, which is a kind of igneous rock that forms when lava cools more slowly than in the case of basalts.
- Breccias are fragments of different rocks compacted and welded together by meteoric impacts and are found in Maria and Highlands.
- The Moon has either a very small core rich in iron ore or no core at all.
- The rocks are rich in Calcium (Ca), Aluminium (Al) and Titanium (Ti)
- There is high abundance of Silicon (Si) and Oxygen (O)
- There is a relative abundance of 3He on the Moon, compared with Earth. This may be due to the fact that over the four billion year history of the Moon, several hundred million tons of solar 3He have impacted directly onto the surface of the Moon and got trapped in minerals such as Ilmenite (a compound of iron and titanium; FeTiO3).
4. Origin of Moon
The origin of the Moon is still not clearly understood and there have been speculations about its origin how it was formed and how it acquired its present orbit around the Earth. Studies using the chemical, mineralogical, isotopic and chronological data led to postulation of five major theories on the origin of the Moon:
The Fission Theory:At some time in the distant past, the Moon had separated from the Earth. Perhaps the Earth was not as round then as it is today and that imbalance caused it to split in two.
The Capture Theory:
The Moon was formed somewhere in the solar system and was later captured by the gravitational field of the Earth.
The Co-accretion Theory:
The Earth and Moon may have been formed at the same time from solar nebula by co-accretion.The Colliding Planetesimal Theory: Moon condensed from the debris of the interaction of Earth-orbiting and Sun-orbiting planetesimals (very large chunks of rocks like asteroids) early in the history of the solar system.
The Giant Impact Theory:
A planetesimal of Mars size had impact with the Earth, early in its history, ejecting large volume of matter from the evolving Earth, which aggregated and formed the Moon.
5. Early Interest
Through the ages Moon has been the heavenly body, which sparked the imagination of mankind more than the planets in our solar system. In the distant past our ancestors looked up to the sky with awe and wonder. At the beginning of recorded history, the passage of time was decided by observing the positions and phases of the Moon. The idea that the Moon was not perfectly smooth can be traced back to 450 B.C. At approximately the same time the Greek astronomer, Hipparchus, using observations and mathematical formulae measured the distance to the Moon as well as the Sun with surprising accuracies. In the Vedic period (1500-500 B.C.), Indian astronomers had determined the orbit of the Moon precisely and based on the phases of the Moon, developed the lunar calendar which is used even now. The Indian astronomer Aryabhata (~500 A.D), after whom the first Indian satellite was named, was one of the early scholars who determined the Moon’s size and distance accurately.
Launch vehicle fleet
Comparison of Indian carrier rockets. Left to right: SLV, ASLV, PSLV, GSLV, GSLV III.
Geopolitical and economic considerations during the 1960s and 1970s compelled India to initiate its own launch vehicle program. During the first phase (1960s-1970s) the country successfully developed a sounding rockets program, and by the 1980s, research had yielded the Satellite Launch Vehicle-3 and the more advanced Augmented Satellite Launch Vehicle (ASLV), complete with operational supporting infrastructure. ISRO further applied its energies to the advancement of launch vehicle technology resulting in the creation of Polar Satellite Launch Vehicle (PSLV) and Geosynchronous Satellite Launch Vehicle (GSLV) technologies.
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