SCIENCE & TECHNOLOGY

Boosting the Indian launch capability
Radhakrishna Rao

Sometime during the first half of this year, as the 414-tonne three stage Geosynchronous Satellite Launch Vehicle (GSLV) equipped with a fully home-grown cryogenic engine stage places GSAT-4 technology demonstrator satellite into a geostationary transfer orbit, a new milestone would have been crossed by the Indian Space Research Organisation (ISRO) in its quest of progressively boosting the Indian launch capability.

Trends

  • Stem cell experiment reverses aging

  • Obama's commitment to NASA

  • Tests reveal Egypt's King Tut's secrets

  • Genome study shows cancer abnormalities

  • African genes may provide secrets to long life

  • Astronauts open viewport shutters

  • Tests fail to predict women's heart risks

  • Chemical DNA testing

Prof Yash Pal

Prof Yash Pal

THIS UNIVERSE
PROF YASH PAL
Why is there an attractive force between two protons inside the nucleus?
Nucleons (protons and neutrons) both have a strong nuclear force with each other. The protons being charged have an additional force with other charged particles, including other protons. The nuclear force is short range while the electrical force can act up to longer distance. We cannot have a nucleus with only two protons, because the electrostatic force would pull such a nucleus apart. However if in addition to two protons you put in a neutron we do get stability because neutron, being neutron, has only a nuclear force, which helps to cancel the repulsion of the two protons. This nucleus is called Helium 3.



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Boosting the Indian launch capability
Radhakrishna Rao

Sometime during the first half of this year, as the 414-tonne three stage Geosynchronous Satellite Launch Vehicle (GSLV) equipped with a fully home-grown cryogenic engine stage places GSAT-4 technology demonstrator satellite into a geostationary transfer orbit, a new milestone would have been crossed by the Indian Space Research Organisation (ISRO) in its quest of progressively boosting the Indian launch capability.

The successful operationalisation of the GSLV featuring an Indian made cryogenic engine stage working on liquid hydrogen and liquid oxygen will help India attain self reliance in launching INSAT class domestic satellites weighing over 2-tonne. Significantly, the GSLV flights accomplished so far from India were based on Russian supplied cryogenic engine stages.

As it is, the complex and technologically challenging cryogenic propulsion system provides a higher level of thrust to the launch vehicle in comparison to earth storable solid and liquid fuel stages. So far only USA, Russia, China, Japan and European Space Agency (ESA) have launched space vehicles with cryogenic engine stages. The upcoming GSLV flight with the Indian cryogenic engine stage carrying 12.5-tonne of liquid hydrogen and liquid oxygen would help in the qualification of the cryogenic engine stage in all respects. Chandrayaan-II probe-a follow on to India's maiden Chandrayaan-1 spacecraft-will be launched by means of GSLV. Similarly, GSLV is likely to be deployed for launching India's first manned flight slated for launch in 2016.On another front, the Bangalore based Antrix Corp, the commercial arm of the Indian space program would be able to expand the scope of its commercial launch service with the introduction of GSLV.

The recent successful ground firing of S-200 solid propellant booster stage, considered the third largest solid propellant rocket motor in the world, has given impetus to ISRO's plan of realising a heavy lift off GSLV-MKIII now under development. The 629 tonne three stage GSLV has been designed to launch a 4-tonne class satellite into a geostationary transfer orbit. Alternatively, it can launch a 10-tonne class satellite into a low earth orbit. Two S-200 booster stage stuffed with 200-tonne of solid fuel will be attached to the core liquid stage of GSLV-MKIII carrying 110-tonne liquid propellant .The upper stage of GSLV-MKIII will be a cryogenic propulsion system with 25-tonne liquid hydrogen and liquid oxygen. As things stand now, the maiden flight of GSLV-MKIII is expected to take place sometime in 2011,

ISRO also has a plan up its sleeve to upgrade the launch capability of GSLV-MKIII by replacing its core stage with semi-cryogenic propulsion system now under development. This change over is expected to help GSLV-MKIII launch a 6-tonne class satellite into a geostationary transfer orbit. Indeed, ISRO plans to use GSLV-MKIII as a platform for trying out new and innovative technological systems for boosting the launch capability. In the ultimate analysis, ISRO hopes to meet its entire launch requirement projected for the future through GSLV-MKIII and its variants.

ISRO is also working on developing technological options for its reusable space transportation system. As part of this project, a series of technology demonstrator missions have been planned .

And for this purpose, a winged reusable vehicle to carry out demonstration mission has been put in place. This winged vehicle will act as flying test bed for evaluating a range of technologies including hypersonic flight, autonomous landing, powered cruise flight and hypersonic flight using air-breathing propulsion.

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Trends
Stem cell experiment reverses aging

WASHINGTON: In a surprise result that can help in the understanding of both aging and cancer, researchers working with an engineered type of stem cell said they reversed the aging process in a rare genetic disease. The team at Children's Hospital Boston and the Harvard Stem Cell Institute were working with a new type of cell called induced pluripotent stem cells or iPS cells, which closely resemble embryonic stem cells but are made from ordinary skin cells.

Obama's commitment to NASA

HOUSTON: President Barack Obama on Wednesday said his commitment to NASA was "unwavering" after his administration's 2011 budget slashed funding to return U.S. astronauts to the moon. "My commitment to NASA is unwavering," Obama said on a video-conference with astronauts aboard the International Space Station. Speaking from the White House, Obama called the outpost orbiting 200 miles above the Earth "a testimony to human ingenuity."

Tests reveal Egypt's King Tut's secrets

CAIRO: Ancient Egypt's teenage king Tutankhamun was born of an incestuous marriage, scientists said on Wednesday, helping to explain why he limped on a club foot and suffered other deformities and genetic defects. Research including tests on the pharaoh's mummy, discovered in 1922 in the Valley of Kings, showed that his parents had been siblings and he had only paternal grandparents.

Genome study shows cancer abnormalities

CHICAGO: Genetic abnormalities-missing DNA or duplicate DNA-that fuel the growth of one type of cancer may actually be at work in several others, U.S. researchers said on Wednesday. The finding, based on a large-scale study of the genetic make-up of 26 different types of cancers, suggests cancer has less to do with where in the body it occurs, and more to do with the genetic changes that cause it to grow.

African genes may provide secrets to long life

WASHINGTON: A genetic peek deep into the heart of Africa confirms that Africans have more genetic diversity than Europeans or Asians and provides insights into how to live a long life despite disease and famine. Researchers sequenced the complete genomes of five southern Africans over the age of 80 -- Archbishop Desmond Tutu from South Africa and four Bushmen from Namibia.

Astronauts open viewport shutters

HOUSTON: Astronauts ventured outside the International Space Station on Tuesday to put the finishing touches to an observation deck that gives residents a panoramic view of the Earth below. On the last of three spacewalks planned for shuttle Endeavour's 14-day mission, astronauts Robert Behnken and Nicholas Patrick removed insulation that protected the viewport's seven windows during its trip into orbit.

Tests fail to predict women's heart risks

CHICAGO: Gene tests that combined over 100 genetic mutations proved ineffective at predicting a woman's risk of a heart attack or stroke, U.S. researchers said on Tuesday. They said high cholesterol, high blood pressure and a family history of heart disease were the strongest predictors of a woman's heart disease risk.

Chemical DNA testing

LONDON: British scientists say they have developed a way of pinpointing variations in a person's genetic code using a chemical test on saliva, meaning quick, cheap DNA tests for risks of certain diseases may be around the corner. Researchers at Edinburgh University said their technique, based on chemical analysis, can deliver reliable results without the need for expensive enzymes used in conventional DNA testing. óReuters

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THIS UNIVERSE
PROF YASH PAL

Why is there an attractive force between two protons inside the nucleus?

Nucleons (protons and neutrons) both have a strong nuclear force with each other. The protons being charged have an additional force with other charged particles, including other protons. The nuclear force is short range while the electrical force can act up to longer distance. We cannot have a nucleus with only two protons, because the electrostatic force would pull such a nucleus apart. However if in addition to two protons you put in a neutron we do get stability because neutron, being neutron, has only a nuclear force, which helps to cancel the repulsion of the two protons. This nucleus is called Helium 3.

In other words, you can build up nuclei of higher and higher mass by putting in protons and increasing the number of neutrons to provide stability. Highest naturally occurring nucleus is that of Uranium 238. This has 92 protons and 146 neutrons. Thus we understand that stability of elements depends on the balancing of the electrical repulsion of protons and mutual nuclear attraction of all the nucleons.

According to Newton's Third Law of Motion, to every action there is equal and opposite reaction, so why does window glass break when a ball or stone hits it?

You will understand it immediately if you change the frame of reference and consider this as a case of the window glass hitting the stone.

Water has less inter-molecular spaces than solids. If we freeze water, its inter-molecular forces should be more. Why is it not?

Water is a very special substance. You know that density of water is maximum at 4 degrees Celsius. Now if you cool the water to 0 degrees Celsius it freezes. Frozen water has a crystalline structure. This means that molecules of water are constrained to form a well defined three dimensional structure. Think of molecules of water as tiny bricks which are made to build a house with those bricks when the water freezes into crystals. It is clear that the volume of a house would be greater than that of the bricks stored properly in rows and columns. In other words the density of ice is less than that of water.

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