Skip to main content

Posts

Showing posts from 2009
Telangana Struggle: By July 1948, 2,500 villages in the south were organised into 'communes' as part of a peasant movement which came to be known as Telangana Struggle. Simultaneously the famous Andhra Thesis for the first time demanded that 'Indian revolution' follow the Chinese path of protracted people's war. In June 1948, a leftist ideological document 'Andhra Letter' laid down a revolutionary strategy based on Mao Tsetung's New Democracy.
1964
CPM splits from united CPI and decides to participate in elections, postponing armed struggle over revolutionary policies to a day when revolutionary situation prevailed in the country.
1965-66
Communist leader Charu Majumdar wrote various articles based on Marx-Lenin-Mao thought during the period, which later came to be known as 'Historic Eight Documents' and formed the basis of naxalite movement.
· First civil liberties organisation was formed with Telugu poet Sri Sri as president following mass arrests …
ea levels likely to rise by more than 4 feet by end of this century




Days before the Copenhagen Conference on Climate Change kicks off, a major study by a group of 100 international scientists has said that sea levels are likely to rise by more than 4 feet by the end of this century. This is twice as much as previously predicted in the Inter-Governmental Panel on Climate Change (IPCC)'s fourth assessment report of 2007. The report released by the Scientific Committee on Antarctic Research (SCAR) is the first comprehensive review of the impact of global warming on Antarctica. The IPCC's 2007 report had projected that sea-levels could rise by 18cm to 59cm by 2099. Subsequent studies of glacial melts in Greenland and Antarctica had raised fears that sea rise could be much higher than that. If these projections come true, most areas in low-lying island nations like the Maldives would go under the sea. Based on earlier studies, the UN's environmental panel has already warned tha…
GROUND SEGMENT FOR CHANDRAYAAN-1 MISSION
The Ground Segment for Chandrayaan-1 comprises of three major elements : the Ground Station Network including the Indian Deep Space Network (IDSN), Mission Operations Complex (MOX)and Indian Space Science Data Centre (ISSDC). This trio of ground facility ensures the success of the mission by providing to and fro conduit of communication, securing good health of the spacecraft, maintaining the orbit and attitude to the requirements of the mission and conducting payload operations. The ground segment is also responsible for making the science data available for the Payload Scientists along with auxiliary information, in addition to archiving of payload and spacecraft data. Payload Operation Centres (POCs) also form a part of the Ground Segment.

olar Satellite Launch VehicleThe Indian Space Research Organisation (ISRO) built its first Polar Satellite Launch Vehicle (PSLV) in the early 90s. The 45 m tall PSLV with a lift-off mass of 295 tonne, had its maiden success on October 15, 1994, when it launched India's IRS-P2 remote sensing satellite into a Polar Sun Synchronous Orbit (SSO) of 820 km altitude. Since its first successful launch in 1994, PSLV has launched nine Indian Remote Sensing satellites as well as two micro satellites HAMSAT and IMS-1 built by ISRO, a recoverable space capsule SRE-1, and fourteen small satellites for foreign customers into polar Sun Synchronous Orbits. Besides, it has launched one Indian meteorological satellite Kalpana-1 into Geosynchronous Transfer Orbit (GTO). PSLV has emerged as ISRO's workhorse launch vehicle and proved its reliability and versatility by scoring continuous successes in launching multiple payloads to both SSO as well as GTO.

Considering the maturity of Polar Satellite L…
spacecraft Description
Spacecraft for lunar mission is :



Cuboid in shape of approximately 1.5 m side.





Weighing 1380 kg at launch and 675 kg at lunar orbit.





Accommodates eleven science payloads.





3-axis stabilized spacecraft using two star sensors, gyros and four reaction wheels.





The power generation would be through a canted single-sided solar array   to provide required power during all phases of the mission. This deployable solar array consisting of a single panel generates 750W of peak power. Solar array along with yoke would be stowed on the south deck of the spacecraft in the launch phase. During eclipse, spacecraft will be powered by Lithium ion (Li-Ion) batteries.





After deployment, the solar panel plane is canted by 30ยบ to the spacecraft pitch axis.





The spacecraft employs a X-band, 0.7m diameter parabolic antenna for payload data transmission. The antenna employs a dual gimbal mechanism to track the earth station when the spacecraft is in lunar orbit.





The spacecraft uses a bi…
Mission Sequence




Chandrayaan-1 spacecraft was launched from the Satish Dhawan Space Centre, SHAR, Sriharikota by PSLV-XL (PSLV-C11) on 22 October 2008 at 06:22 hrs IST in an highly elliptical initial orbit (IO) with perigee (nearest point to the Earth) of 255 km and an apogee (farthest point from the Earth) of 22,860 km, inclined at an angle of 17.9 deg to the equator. In this initial orbit, Chandrayaan orbited the Earth once in about six and a half hours.





Subsequently, the spacecraft's Liquid Apogee Motor (LAM) firing was done on 23 October at 09:00 hrs IST, when the spacecraft was near perigee, to raise the apogee to 37,900 km while the perigee to 305 km. The spacecraft took eleven hours to go round the Earth once.





The orbit was further raised to 336 km x 74,715 km on 25 October at 05:48 hrs IST. In this orbit, spacecraft took about twenty-five and a half hours to orbit the Earth once.





The LAM was fired again on 26 October at 07:08 hrs IST to take the Chandrayaan-1 spacecraft to ex…
Scientific Objectives

The Chandrayaan-1 mission is aimed at high-resolution remote sensing of the moon in visible, near infrared (NIR), low energy X-rays and high-energy X-ray regions. Specifically the objectives are







To prepare a three-dimensional atlas (with high spatial and altitude resolution of 5-10 m) of both near and far side of the moon.








To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium as well as high atomic number elements such as Radon, Uranium & Thorium with high spatial resolution.


The Simultaneous photo geological, mineralogical and chemical mapping through Chandrayaan-1 mission will enable identification of different geological units to infer the early evolutionary history of the Moon. The chemical mapping will enable to determine the stratigraphy and nature of the Moon's crust and thereby test certain aspects of magma ocean hypo…
CHANDRAYAAN-1: India's first mission to Moon
"THE MOON"with the history of the early solar system etched on it beckons mankind from time immemorial to admire its marvels and discover its secrets. Understanding the moon provides a pathway to unravel the early evolution of the solar system and that of the planet earth.

Through the ages, the Moon, our closest celestial body has aroused curiosity in our mind much more than any other objects in the sky. This led to scientific study of the Moon, driven by human desire and quest for knowledge. This is also reflected in the ancient verse.


Exploration of the moon got a boost with the advent of the space age and the decades of sixties and seventies saw a myriad of successful unmanned and manned missions to moon. This was followed by a hiatus of about one and a half-decade. During this period we refined our knowledge about the origin and evolution of the moon and its place as a link to understand the early history of the Solar System…
world war II








1 September
1939: Germany invades Poland
German forces attack Poland across all frontiers and its planes bomb Polish cities, including the capital, Warsaw - Britain and France prepare to declare war.




3 September
1939: Britain and France declare war on Germany
Britain and France are at war with Germany following the invasion of Poland two days ago.




10 May
1940: Churchill takes helm as Germans advance
German forces invade the Low Countries by air and land, while in London, Chamberlain is replaced by Churchill.




4 June
1940: Dunkirk rescue is over - Churchill defiant
As the last Allied soldier leaves Dunkirk, the British Prime Minister vows his forces "shall never surrender".




14 June
1940: German troops enter Paris
German troops march into Paris forcing French and allied troops to retreat.


World War II


10 Jul
1940: Luftwaffe launches Battle of Britain

07 Sep
1940: London blitzed by German bombers

15 Sep
1940: Victory for RAF in Battle of Britain

15 Nov
1940: Germans bomb Coventry to d…