: Tathagat Nawadia :

Masters of Dawn

2011-09-27T20:39:00.004+05:30

Deep down the copse tranquil

before the abysmal cosmos

comes my love divine

Trace you eternal grace

amid naught thy foot

deify me thou erotic being

I fear being dimineur to soot

Enervate me from profane lust

you rout heavens hands down

entrust me , I am not ephemeral

vos phoenix from dust.

Dissoudre me in vos eyes

i drink carino breath

by the brim of vos lips

before the blonde skies

I am no wordmill

vos ardor usurp me of all my will

The moment too bliss

my surreal territory waving by your kiss

Tu pale away

in the gulf of nothingness

Empowered am I by multitude

of infinite darkness

This psyche squirms

solicit thy imminence sedative

Persisting this mortal realm

has never been so aggressive

I cry my blood out

confair en me I vos solitary faith

Lone lonely loner

Find me o you somber death

Here I trance along

the paths of impending disaster

Standing there as an onlooker

the decree of the universal master

Cielo nice and high

brisk is the sun that shine

Unwitting are those paltry mortals

this is the end of the line

My judgment stands

over the cosmic nurse

Obliged by purpose of existence

was I littered to curse

I penser culminating proclamation

Arbitrary wanders derrubar laws of nature

Hinting smile maketh mon esprit

on the humans so miniature

Clouds take down the sun

Shadows leave mon back

on the sigh of my nod

I pronounce annihilation

Rise my god , I am antigod

Anonymous soul beseech

in hushed voices

Ballad fatale uttered over

muted worldly noises

My last footsteps deemed

to conquer a thousand suns

Infinite gloom booms

over furious horizons

War spread with vicious circles

as nothing stands no chance

oceans weep the ailing earth

by their rings of fiery dance

Open o my ravenous ground

De lava faults worldly bounds

Unicorns clipped , Oceans fly

the universe itself begins to die

Firmament comeca a flicker

in the murmure de la night

God , a figure among cyphers

Unassailable is my might

T’was a nine days wonder

Reduced to nothing from a million ton

and in a maison isolee

the mother killed by her own son

Debout triumphant over my kill

I was, am and I will.

Drained of larmes

feeling my essence wilt

In spite of wholly wisdom

I failed to recognize guilt

Before this monstrous visage

heavens fall and die

Was I disgustingly incorporeal

my life was nothing but a lie

Traitor of human ardor

Time and space quaver

I close my savage eyes

And lay there forever.

Note :

a) This is a pre-release of Masters of Dawn , the final poem is due 2012 (Q1)

b) Concept of Anti-God is purely fictional brainchild and bears no resemblance with any myth, epic, novel

c) Suggestions are welcome

And thank you sweetheart for being real

Independent Speech

2011-08-14T22:31:00.002+05:30

Morning and welcome to the 65^th year of independent India.

Well this day needs no introduction. Today we re-dedicate ourselves to country’s prosperity and analyze the flaws we have inflicted on it through our deeds. Today we nick time from our harried schedules to pay respects to the martyrs of war who relieved us from the shackles of despotic English rule. Today we celebrate our constitution. Today we celebrate our independence.

I sucked in History; however I am quite acquainted to Gandhian principle – I respect him quite well. But in today’s scenario some Gandhian principles seems to retaliate, if all he said was ideal then we might have found ourselves as an eminent nation. All in all i would say if anything is to be considered, it’s the freedom, the independence they had procured after so much of toil and detriment and it’s definitely not rationed for nonsensical development.

We stand as the vastest democracy of the world; we have more freedom than any other country and we have used it to quite an extent.

Prisoners have freedom to keep mobile phones, not only inside outsiders have equal freedom to trespass and attack the prisoners.

----

In times of power cut we must not be confined to our houses, we have freedom to come out and breathe fresh air and when power doesn’t get restored we have freedom to strike the electricity office and the officers of electricity board have equal freedom to flee from their offices.

----

If you are a Government contractor there is no compulsion that you should lay the roads properly as per specifications. You have every freedom to lay road as per your wish and you have every freedom of not laying the roads at all. In the rains if the road dissolves the people have every freedom to reach their homes and offices by boats or by swimming. You have every freedom to halt your cars on the zebra crossings.

----

Everybody has freedom to choose their occupation. You have every right to smuggle rice, cement, kidneys, gold, televisions or whatever. You have equal freedom to conventionally start a business of pirated CDs in the comforts of your house.

----

You have every freedom to print currency notes, nobody stopping you, go ahead. You have every freedom to join the jihad. Maoists and terrorists have equal freedom to derail any train they want or bomb a few people.

----

The politicians have freedom to loot lakhs and crores of rupees as per their ability. We have freedom to know how much money the politicians have looted through daily and news channels and we have equal freedom to elect the politicians we want to be corrupted by in the next 4 years.

The fact is that we are pushing freedom to its extremities and encumbering the development we are pronouncing. Even after 65 years of independence we are hanging from the labyrinth of several dogmas and doctrines identified by the constitution, but the essence of patriotism is still deficient. We are loud enough to sing the national anthem but we are shameless to spit on the roads.

Our India has been on the road of development for quite a time and is developing as I speak. But opening of malls, pubs, five star hotels doesn’t indicate development; it’s just the function of time and need. True sense of development lies in the development of the mentality of the people.

Our leaders and government in spite of their paper abilities are rearing the nation with the foundation of whoppers and niggardliness. We are producing a copy-paste system of the west with no ingenuity in our national framework. Our intelligentsia is nurtured in erroneous milieu. It’s not the China and Japan is bestowed with more brilliancy on their side, it’s just that they are infatuated with innovative minds and extravagant love for their country.

We have been developing for the sake of development and the not for the want for development.

Why is that most MNCs thriving in India are west initiated? Why that India produces just a few entrepreneurs of its own? Why is that that our educational reform stresses on learning the things which has already been discovered and not fashion ideas of our own? Why is that with a normal human brain we have lost capacity to innovate, think different, be different. In this world if you are not different, you are no different. We cannot afford to be the cattle class. You may well please seek answers within yourself and disregard illusionary pride we have babied for years.

Tomorrow we fight for our second independence. I don’t know how many of have the read Lokpal, I got a 41 page document of the Lokpal, I didn’t get time to go through all of it but 2 commendable things I noticed is the about is better governmental procedures and strict control and the privatization of governmental agencies.

You might well think that I am talking you into shit, but you can cut me short if I am preaching anything but reality. If anything we want to change, it’s the mode of change.

I celebrate independence as a centenary of enhanced and gracious amendments and I feel every Indian feels this way.

My fellow citizens whatever I have been speaking calls for a great deal of introspection.

Let’s give India what it asks from us.

Thank you and JAI HIND.

Donuts and Pies

2011-08-01T21:19:00.002+05:30

We live the way we fire, we fire the way we live

There was a king, who ruled the streets of dusk

Lived loved the stripe of a bond

But of love this riddled him for years

(Restricted Document)

Project Details

2011-07-26T22:28:00.000+05:30

Project Details

1.1) Introduction – Tathagat

1.2) Objectives – Aakrity Singh

2.1) Space Shuttle Introduction – Aakrity Singh

2.2) Crew – Upvan

2.3) Components of Space Shuttle – Tathagat

2.4) Phases of Space Shuttle – Tathagat

2.5) Orbiter Vehicle – Aakrity Singh

2.5.1) Remote Manipulator System (RMS) – Lali

2.5.2) Thermal Protection System (TPS) – Harsha

2.5.3) why does shuttle remain stable in earth’s orbit – ?

2.5.4) Reaction Control System (RCS) – Lali

2.5.5) Landing on Earth – Tathagat

2.5.5.1) Challenges during landing – Tathagat

2.5.5.2) Heating by the plasma – Aakrity

2.5.5.3) Process of Reentry – Tathagat

2.5.6) Pressurized Cabin – Harsha

2.5.7) Propulsion System – X

2.5.7.0) Simple Physics Involved – Rishav

2.5.7.1) Solid Rocket Boosters (SRBs) – Lali

2.5.7.2) Space Shuttle main engines (SSMEs) – Tathagat

2.5.7.3) Orbital Maneuvering System (OMS) - ?

2.5.7.4) External Fuel Tank (EFT) – Tathagat / Rishav

2.5.7.5) Hydraulic System – Upvan

2.5.8) Docking – Aakrity

3.1) Challenges – Lali

3.2) Solution – Lali

3.3) Space suits – Tathagat

1.1) Introduction – Tathagat

q Aerospace engineering is the science of spacecraft. It is further divided into aeronautical engineering and astronautical engineering. The former deals with the science of spacecraft in earths atmosphere while the later deals with science behind spacecrafts outside the earth’s atmosphere.

q Space Shuttle was developed by NASA in 1970 as a reusable rocket for transporting humans and cargo (i.e. satellites) to and from earth’s orbit. It is designed for 100 flights.

q NASA has made 5 space shuttles till date : Columbia, Challenger , Discovery, Atlantis, Endeavour . Columbia was the first to make its flight .Challenger disintegrated 73 seconds after launch in 1986, and Endeavour was built as a replacement for Challenger from structural spare components. Columbia broke apart during re-entry in 2003.

q NASA is collaborated by many countries which include Russia, Canada, England , Japan, India.

1.2) Objectives - Aakrity

a) Advancing human exploration and providing safe access to space in support of human operations in low Earth orbit.

b) The Shuttle’s primary role is to complete the assembly of the International Space Station (ISS)

c) Building of lunar bases, nuclear interplanetary rocket stages, and manned Mars expeditions

d) Aeronautics : pioneers and proves new flight technologies that improve our ability to explore and which have practical applications on Earth.

e) Exploration Systems : creates capabilities for sustainable human and robotic exploration.

f) Science : explores the Earth, solar system and universe beyond; charts the best route of discovery ,and keeps the human world updated with the latest space happening of the Universe.

g) Threats to Earth : Identifies the threats the universal constituents might posses to earth.

h) Climate : Climate change research and observations.

i) Aviation : Exploring reliable, increasing commercial spaceflight capabilities, green aviation.

j) Payloads : Numerous satellites and interplanetary probes, space station components, space science experiments are called payloads .They are sent as cargo in space through the shuttles.

2.1) Space Shuttle Introduction - Aakrity

q Space shuttle or Space Transportation System (STS) is a reusable system and orbital spacecraft operated by NASA for human spaceflight missions.

q Shuttle leaves the earth vertically. It weights about 2.0 million kg with 3 million kg of thrust from its multiple propulsion systems. It lands on earth on a conventional airport runway.

2.2) Crew - Upvan

q Crew forms the integral part of a space mission and is crucial for its success.

q There are around 7 crew members in the space mission.

q The Crew is lead by the commander and the pilot. Their primary responsibility is to fly the shuttle as a launch vehicle, spacecraft, and aircraft.

q The Remaining five members are experts in that mission's objectives and cargo, which are usually space experiments or artificial satellites. They are led by the lead astronaut who ensures that mission achieves all its objectives. Often the 5 members are payload scientists from other nations

2.3) Components of Space Mission - Tathagat

2.4) Phases of Space Shuttle – Tathagat

2.5) Orbital vehicle – Aakrity

q The orbiter is a reusable winged "space-plane", a mixture of rockets, spacecraft, and aircraft. This space-plane can carry crews and payloads into Earth orbit, perform on-orbit operations, then re-enter the atmosphere and land as a glider, returning her crew and any on-board payload to the Earth.

q Challenger, Columbia, Discovery, Endeavour and Enterprise all made by the Rockwell International Company .

q Body of shuttle is made from the aluminum alloy; engine thrust structure is made from titanium alloy; windows are made of aluminum silicate glass and fused silica glass, comprising of internal pressure pane, mid 1.5 inch thick optical pane and external thermal pane.

q Its belly and nose is made from thermal insulating tiles.

q The orbiter vehicle has primarily three sections:

(a)Flight deck : Commander and pilot occupy the flight deck surrounded by computer controls and switches. In a seven member crew 2 astronauts are positioned just behind the pilot and commander to control the craft in case of emergency.

(b) Mid deck : It is below the flight deck. The galley toilet, sleep stations, and storage and experiment lockers are found in the mid-deck. Side hatches for passage to and from the vehicle is located in the mid deck.

(c) Utility Area : It has air and water tanks. Cargo bay carries satellites, scientific laboratories, foundations and components of space stations. It also serves as a workstation for astronauts to repair and assemble satellites.

2.5.1) Remote Manipulator System – Lali

q Remote Manipulator System (RMS) is developed by Canadian Government

q It is a robotic arm of 15.2m(s) running along the cargo bay area / utility area. It has a diameter of 15 inches and weights 450 kg(s).

q The RMS has six joints that correspond roughly to the joints of the human arm.

q The RMS can move anything from satellites to astronauts to and from the cargo bay or to different points in nearby space. It is the carrier of the components of the ISS from the cargo area to astronauts in space. The Canadarm can also retrieve, repair and deploy satellites .It inspects the surface of the space shuttle by the high precision camera attached to its head.

q It is also called Canadarm.

2.5.2) Thermal Protection System (TPS) – Harsha

q The orbiter not only encounters extreme temperatures of 3500°F but also as low as -250°F , the part of the shuttle which is exposed to the direct rays of the sun faces very high temperatures whereas the part of shuttle in the silhouette faces temperatures which much low than freezing point.

q The orbiter's outer structural skin is constructed primarily of aluminum and graphite epoxy which cannot withstand temperatures over 350°F.

q TPC components : namely Reinforced Carbon-Carbon , Black high temperature reusable surface insulation tiles, felt reusable Nomex are spread over the shuttle selected surfaces to encounter a temperature range of -250 °F cold space and 3500 °F heat of reentry.

q Reinforced Carbon-Carbon is made from carbon as a result pyrolised resin and furfural alcohol. Its outer surface is made from alumina, silicon and silicon carbide. It is present on wing edges, nose cap, external tank structural attachment area and protects are exceeding 3000°F.

q Black high temperature reusable surface insulation tiles tiles are made of a low-density, high-purity silica 99.8-percent made strong by ceramic bonding. It is used underside the orbiter, RCS pods and some parts of OMS, elevon edges, upper body flap and upper side of wings. They are black for better emission. These tiles at 2300°F can be held with bare hands without injury as they rapidly dissipate heat.

q Nomex is a white blanket covering about 50% of the shuttles' surface and encounters temperatures below 700°F and even negative temperatures.

2.5.3) Why does shuttle remain stable in Earth Orbit -

q The stability of the shuttle in an earth’s orbit is based on the simple principle of centripetal and centrifugal force.

q The orbit in which the shuttle moves experiences a force of gravity just a bit less than that which is experienced on earth.

q In order to counteract the gravitational force of earth it has to move with a critical velocity of 8km/s.

q Due to this astronauts feel the weightlessness. The whole system moves with this speed so that there is no relative motion.

q The critical velocity of 8 km/s is called orbital speed.

2.5.4) Reaction Control System (RCS) – Lali

q RCS is composed of 44 small liquid fueled rocket thrusters controlled by a very sophisticated system called fly-by-wire.

q RCS makes use of monomethylhydrazine which is oxidized by nitrogen tetroxide.

q The RCS provides fine pointing and attitude control along the pitch , roll and yaw axis during all phases of flight “ launching , orbit and re-entry .”

q It is used for station keeping of the orbiter.

q It is responsible for pumping and pressurizing fuel in zero gravity.

q RCS monitors the conservation of fuel through-out the mission.

2.5.5) Landing on Earth – Tathagat

q Shuttle lands on a conventional runway cleared by the Federal Aviation Administration and the Air Force. The Orbiter nearly always lands at either Edwards Air Force Base (California) or near to the Patrick Air Force Base (Florida).

q Biggest challenge in landing is to prevent the shuttle to make a high speed landing while descent through a great height while it doesn’t burn up.

q Although there are elevons on the delta wings, airbrake, movable body flap but these are effective only in earths lower levels of atmosphere where the air density is thick.

q In order to deorbit shuttle has to lose most of it’s orbital speed.

2.5.5.1) Challenges during landing – Tathagat

q Strategy of safe landing is based on the principle of losing the orbital speed of 8 km/ hour , i.e. , losing maximum of its kinetic energy.

q As soon as the thrusters decrease the critical velocity the shuttle starts descending into the earth’s atmosphere.

q There are 4 ways in which the OV can shed its K.E. and P.E.

1. POWER DECELERATION : This can be achieved by the rocket thrust opposed to the direction of motion , this can be done at the very beginning of the reentry. However this method proves to be quite ineffective as most of the fuel is consumed in maneuvering.

2. ENERGY EXCHANGE : This method is the conversion of kinetic energy of the shuttle into potential energy. However no technique has proved useful in harnessing such a large magnitude of energy in small intervals of time.

3. MASS SHEDDING : This method is conceptually exemplified by a pilot ejecting from his damaged plane by smaller portable shuttle which ejects from the main one - most of the system's energy remains invested in the part that carries on and crashes. However the principle of NASA STS program of the “reusability of shuttle” and “leaving no debris in space” rules out this idea. European Space Agencies make use of this technique.

4. ENERGY DISSIPATION : This method is based on the principal of converting the K.E. of shuttle into useless forms heat and sound. This method is most feasible as the thermal tiles enclosing the shuttle has a rapid heat dissipation capability. In the lower atmospheres the where the density of air column increases the elevons , rudder and air brake comes into play. The shuttle releases the parachutes and wheel-brakes are employed to lower the speed from 350 km/Hr to 150 km/hr.

2.5.5.2) Heating by the Plasma – Aakrity

q It is assumed that most of heating is a function of friction, i.e., viscous drag of the atmosphere. But most of the heating is done by the plasma, heating by friction is dominant only in the lower levels of atmosphere.

q The Orbiter vehicle thus descends into a sea of superheated plasma.

q Plasma , being the fourth state of matter has proportionality of pressure and temperature

q Energy density at such high speed is enough to dissociate and ionize atmospheric molecules.

q Pressure wave in the upper level of the atmosphere and extreme speed of the shuttle leads to high pressure and intensifies the effect of plasma.

q The plasma stream is electrostatically charged and causes intense local heating on the acute contours of the shuttle’s body

2.5.5.3) Process of Re-entry – Tathagat

q Initial height of the space shuttle : 150 km ; Initial speed of the space shuttle : 29000 km/ hr.

q A speed trim of 300 km/ hr unsettles the critical velocity and is enough to initiate descent.

q Trimming is done but firing up the large rocket motors opposite to the sense of motion. By moving in yaw and pitch fashions the shuttle directs the main engines against the direction of motion . After trimming the speed the shuttle , the shuttle directs it nose towards the face of earth. This process utilizes the remaining fuel of the shuttle taking the shuttle to an altitude of 120 km.

q At this point of time plasma flare begins.

q Now the angle of attack is critical. The shuttle is maintained at an critical angle of 40° by automatic thrusters. Any shallower , the shuttle will face excessive lift and will overfly it’s destination ; any steeper , it will burn up.

q At an altitude of 85 km , the flight surface becomes usable , the automated system performs 4 S-Bends with banking at maximum 80° on a full extent roll. This drastically decreases the speed of the shuttle

q The shuttle is never shrouded completely with plasma flare so communication with NASA space control is always maintained.

q At an altitude of 40 km and craft clocking 10000 km/ hr , plasma flare has ceased; now factors like atmospheric drag comes into play. Air brakes ,elevons ,rudders are employed to bring down the speed to 4000 km/ hr into stable supersonic regime.

q Shuttle is 40 km away from the runway ; pilot directs the nose in landing mode , employs the landing gear and the parachutes ; the speed of touchdown is 350 km/hr ; Finally shuttle comes to a halt.

2.5.6) Pressurized Cabin - Harsha

q The whole craft is pressurized at around 1.14 atm

q An Airlock mechanism depressurizes the space-suits before a walk in space and repressurizes before and astronaut enters the shuttle. It also prevents the shuttle from losing pressure to the outer space as the astronauts move in and out of the shuttle.

2.5.7.0) Simple Physics Involved – Rishav

IN EARTH’s ATMOSPHERE

q Based on Newton's 3^rd law , the burning fuel exerts the reaction force on the shuttle and makes it’s ascent.

OUTSIDE EARTH’s ATMOSPHERE

q Its based on the principle of the linear conservation of motion , i.e. , the product of mass and velocity remains constant. Conservation of momentum can be applied in an isolated system when no external force is acting. Considering the fuel and the shuttle in an isolated system the combined momentum of fuel and shuttle is zero. The fuel is jettisoned off from the engines have negative momentum , in order to nullify the total momentum to zero the space shuttle moves in the direction opposite to that of the outburst fuel.

2.5.7.1) SRBs – Lali

q They are located on either sides of the orange colored external fuel tank.

q The 2 SRB’s have a combined thrust of 26 million Newton and provide most of the power of the shuttle for the first two minutes of the flight.

q The solid rocket motor is the largest solid propellant motor ever made.

q Each SRB has about 450,000 kg of solid propellant which looks like a synthetic hard rubber. Solid Propellant consists of powdered aluminum mixed with oxygen and a chemical ammonium perchlorate.

q The SRB’s take the shuttle at a height of 45 km and 4828 km/ hr before they are separated by the booster separator motors and fall into the ocean to be refurbished and prepared for the next flight.

2.5.7.2) SSMEs

q Manufactured by Rocket-Dyne.

q The 3 main shuttle engines are in the shape of an equilateral triangle

q After the SRB’s are jettisoned off , the SSMEs provide the thrust for 8.5 min taking the velocity from 4828 km/ hr to 27400 km/ hr and altitude from 45 km to 150 km, i.e., in the orbit.

q The 3 engines have a combined thrust of 5.3 million Newton and is capable of achieving the 3g

q As the Shuttle accelerates, the main engines burn a half-million gallons of liquid propellant provided by the large, orange external fuel tank. The main engines burn liquid hydrogen -- the second coldest liquid on Earth at -252.8 degrees Celsius and liquid oxygen.

q The liquid fuel inside the craft is reserved for in-orbit operation and maneuvering .

q These engines are removed for maintenance , from the shuttle after the mission and is designed for 55 flights

q These 3 engines can be swiveled 10.5 vertically and 8.5 horizontally by the hydraulic system in order to change the direction of thrust

2.5.7.3) OMS - ?

q As soon as the shuttle achieves an altitude of 150 km , it starts orbiting the earth ; this point is called the orbital insertion point. The main engines are shut down and the OMS gets operational.

q OMS is handled on the basis of the RCS consisting of 44 small liquid fueled rocket thrusters which are cluttered around the nose and either sides of the tail.

q The main function of the OMS is to change the orbit in which the shuttle is moving. The orbital insertion point has to be tampered with to facilate shuttle’s important work.

2.5.7.4) ET – Tathagat / Rishav

q It is the gas tank/backbone of the shuttle providing it with most of the fuel during it ascent.

q The EFT contains oxygen and hydrogen in a ratio of 6:1.

q It carries 536,000 gallons of fuel.

q The EFT has 3 primary components oxygen tank , hydrogen tank and an intertank

q The previous design used foam ramp to prevent the buildup of ice , but it led to the breaking up of a foam particle which burned a hole in the OV leading to the most deadliest disaster in space “ the Colombia disaster .”The new design uses heater to prevent the buildup of ice.

q The skin of the EFT is covered with spray-on polyisocyanurate foam to keep the propellants at acceptable temperatures.

q The tank propellants are fed to the SSMEs for usage through a 17 inch thick pipe which branches inside the OV.

The EFT is the only part which is not reusable , it is released in the atmosphere once the fuel is exhausted and it burns up on it’s way to earth.

2.5.7.5) Hydraulic System – Upvan

q The hydraulic system consists of Auxiliary Power Unit (APU) which burn hydrazine to provide hydraulic pressure to all hydraulic devices

q Hydraulic Systems controls the calibration of the SSMEs under computerized flight control.

q It controls the aero surfaces (e.g. elevons , air brake , rudder).

q It controls the open and close of main cargo bay’s doors.

2.5.8) Docking – Aakrity

q Docking is the process in which the shuttle docks or joins the International Space Station.

q Docking systems are controlled by the RMS

q Docking is necessary for updating the Satellites ; adding new sections , solar panel , transmitters and arial ; overhauling damaged parts

3.1) Challenges in Space - Lali

q Debris (rubbish) from previous space missions and micrometriods posses’ threat.

q Astronauts have to face highly accelerated ascent and descent.

q Basic needs as breathing, eating and drinking, elimination of body wastes, and sleeping.

q Microgravity.

q Space Radiations

3.2) Solution (Self Explanatory ) – Lali

3.3) Space Suit - Tathagat

Mission Spacecraft

2011-02-23T09:35:00.000+05:30

MISSION SPACECRAFT

Tathagat Nawadia

Overview

Aerospace engineering is the branch of engineering behind the design, construction and science of aircraft and spacecraft. It is broken into two major and overlapping branches: aeronautical engineering and astronautical engineering. The former deals with craft that stay within Earth's atmosphere, and the latter deals with craft that operates outside of Earth's atmosphere.

Space Shuttle, spacecraft designed for transporting humans and cargo to and from orbit around Earth. The United States National Aeronautics and Space Administration (NASA) developed the shuttle in the 1970s to serve as a reusable rocket and spacecraft. This objective differed significantly from that of previous space programs in which the launch and space vehicles could be used only once. After ten years of preparation, the first space shuttle, Columbia, was launched on April 12, 1981. Today NASA has three space shuttles: Discovery, acquired in 1983; Atlantis, which arrived in 1985; and Endeavour, which joined the fleet in 1991. The Union of Soviet Socialist Republics (USSR) started a shuttle program in 1988 with the Buran space shuttle, but the program was halted in 1993.

The space shuttle was initially used to deploy satellites in orbit; to carry scientific experiments such as Spacelab, a modular arrangement of experiments installed in the shuttle's cargo bay; and to carry out military missions. As the program matured, the space shuttle was also used to service and repair orbiting satellites, to retrieve and return to Earth previously deployed spacecraft, and to help build and maintain the International Space Station.

The space shuttle carries a wide range of equipment, known as the payload, into space, ranging from communication, military, and astronomical satellites; space experiments for studying the apparent weightlessness (called microgravity) experienced aboard a shuttle flight; and human experimental facilities. Often, NASA collaborates with other countries by allowing them to use shuttle cargo space for special projects.

Contents

1.) Space Shuttle

1.1) Crew

1.2) Components of space mission

1.3) Orbiter Vehicle (OV)

1.3.1) Remote manipulator system (RMS)

1.3.2) Thermal protection system or (TPS)

1.3.3) Landing in earth’s atmosphere

1.3.3.1) Challenges during landing

1.3.3.2) Heating by the Plasma

1.3.3.3) Process of Reentry

1.3.4) Reaction control systems (RCS)

1.3.5) Pressurized cabin

1.3.6) Propulsion

1.3.6.1) Physics involved

1.3.6.2) SRBs (SOLID ROCKET BOOSTERS)

1.3.6.3) SSMEs (SPACE SHUTTLE MAIN ENGINE)

1.3.6.4) OMS (ORBITAL MANEUVERING SYSTEMS)

1.3.6.5) EFT (EXTERNAL FUEL TANK)

1.3.7) Hydraulic Systems

1.3.8) Reason for the space shuttle to remain stable earth’s orbit

1.3.9) Docking

2.) Space Events

3.) Living in Space

3.1) Challenges

3.2) Solutions

3.3) Space suits


1.	)Space Shuttle

The space shuttle is designed to leave Earth as a vertically launched rocket weighing up to 2.0 million kg (4.5 million lb) with 3 million kg (7 million lb) of thrust from its multiple propulsion systems. The orbiter segment returns from space—withstanding the intense heat when entering Earth's atmosphere. Flown by the shuttle crew much like an aircraft, the shuttle lands horizontally on a conventional airport runway.

1.1) Crew

The crew of the shuttle is an integral part of the system and is critical to the success of each mission. The flight crew is led by the commander and backed up by the pilot—both are professional astronauts and proven pilots with extensive space systems and operations training. Their primary responsibility is to fly the shuttle as a launch vehicle, spacecraft, and aircraft.

The remaining crew members—up to five more people—are responsible for the unique aspects of a particular space mission. The mission specialist is the lead astronaut and ensures that the mission meets all the objectives. Payload specialists are experts in that mission's objectives and cargo, which are usually space experiments or artificial satellites. Often the payload specialists are astronauts from other countries on board to help with a project in which their country has an interest.

1.2) Components of an space mission

The space-shuttle system, called the Space Transportation System (STS), remains the most technologically advanced and complex machine in the world. It consists of the orbiter, propulsion systems—two solid rocket boosters (SRBs) and three main engines—and an external fuel tank.

1.3) Orbiter

The orbiter is a reusable winged "space-plane", a mixture of rockets, spacecraft, and aircraft. This space-plane can carry crews and payloads into Earth orbit, perform on-orbit operations, then re-enter the atmosphere and land as a glider, returning her crew and any on-board payload to the Earth. A total of six Orbiters were built for flight: Atlantis, Challenger, Columbia, Discovery, Endeavour and Enterprise all made by the Rockwell International Company . Challenger was destroyed in an accident after launch. Endeavour was built as Challenger's replacement, and was first launched in 1992. In 2003, Columbia was destroyed during re-entry , leaving just three remaining Orbiters. Two were to be used for the last time in flights during 2010, Atlantis in May, Discovery in November. Endeavour is scheduled to make its final flight in January 2011. The orbiter structure is made primarily from aluminum alloy, although the engine thrust structure is made from titanium alloy. The windows are made of aluminum silicate glass and fused silica glass, and comprise an internal pressure pane, a 1.3-inch-thick (33 mm) optical pane, and an external thermal pane.

An orbiter has three sections

(i) Flight deck-commander and pilot control the whole craft and are surrounded by switches computer and controls. In a seven member crew 2 astronauts are positioned just behind the pilot and commander to control the craft in case of emergency. The other three astronauts are positioned in the mid deck

(ii) Mid deck-It is below flight deck. The galley, toilet, sleep stations, and storage and experiment lockers are found in the mid-deck. Also located in the mid-deck are the side hatches for passage to and from the vehicle before and after landing. Simplified Aid for EVA Rescue, or SAFER, are units strap on an astronaut's back over the space suit and allow an astronaut to move about in space without being tethered to the shuttle or to facilate them to space walk.

(iii) Utility area-it has air and water tanks. Cargo bay carries satellites, spacecraft, and scientific laboratories. It also is a workstation for astronauts to repair satellites, a foundation from which to erect space structures, and a storage area for satellites retrieved from space to be returned to Earth.

1.3.1) Remote manipulator system (RMS)

It was developed and funded by the Canadian government is a robotic arm of 15m and run along the cargo bay area. The RMS can move anything from satellites to astronauts to and from the cargo bay or to different points in nearby space. It is also known as Canadarm.

1.3.2) Thermal protection system or (TPS)

The orbiter's aluminum structure cannot withstand temperatures over 175 °C (350 °F) without structural failure. Aerodynamic heating during reentry would push the temperature well above this level in areas, so an effective insulator is needed.

Thermal tile insulation and larger flexible sheets of insulating material. Cover the underbelly, bottom of the wings, and other heat-bearing surfaces of the orbiter and protect it during its fiery reentry into Earth's atmosphere. Now asbestos is used for better insulation. In space even small sand like particle can damage the metallic body of the craft. Withstands -250 °F cold space and 3000 °F heat of reentry.

.the shuttle's silicate fiber tiles were designed to be used for 100 missions before requiring replacement so as to sustain the heat when the craft reenters the earth’s atmosphere. These tiles are incredibly lightweight and dissipate heat so quickly that a white-hot tile with a temperature of 1260°C (2300°F) can be taken from an oven and held in bare hands without injury.

1.3.3) Landing in earth’s atmosphere

The shuttle faces as high temperatures of 3000°F during reentry.

There are four elevons mounted at the trailing edges of the delta wings, and the combination rudder and speed brake is attached at the trailing edge of the vertical stabilizer. These, along with a movable body flap, control the Orbiter during her later stages of descent through the atmosphere and her landing. Elevons, rudder and the delta wings are effective only in the earth’s atmosphere.

Generally the crafts land in areas that have been specially-cleared by both the Federal Aviation Administration and the Air Force. The Orbiter nearly always lands at either Edwards Air Force Base (California) or near to the Patrick Air Force Base (Florida).

1.3.3.1) Challenges during landing

In order to make a safe landing, a returning spacecraft has to lose nearly all of that orbital speed. The operation is basically a reversal of the launch phase, and this means that the returning craft must sink as much kinetic energy. Theoretically speaking, there are four fundamentally different methods of doing this:

· Powered Deceleration:

This can be achieved by rocket thrust opposed to the direction of motion. The shuttle does this at the very beginning of its re-entry, to trim the speed and so initiate the descent from orbit but it doesn’t really make a difference during reentry. In addition the craft will have to carry even more fuel.

· Energy Exchange

This ingenious braking method requires the conversion of kinetic energy into potential energy. But at present it is much beyond mechanical feasibility to attain such mechanism.

· Mass Shedding

This method is conceptually exemplified by a pilot ejecting from his damaged plane by smaller portable shuttle which ejects from the main one - most of the system's energy remains invested in the part that carries on and crashes. Though the idea works, the shuttle program's fundamental premise of orbiter re-usability precludes it. The shuttle program, though, is bound by the principle that everything that enters earth orbit comes home again.

· Energy Dissipation

This method differs from energy exchange in that the kinetic energy is progressively (and wastefully) converted to another form, such as heat, as the descent proceeds. The amount of energy that must be dissipated is very large. Stopping a one hundred tonne craft from a speed of 8 km per second in eighty minutes requires nearly 2,000 megawatts of power.

1.3.3.2) Heating by the Plasma

It's usually assumed that the mechanism of heating in re-entry is by friction i.e., viscous drag in the atmosphere. In fact this is the predominant mechanism only at lower altitudes, as air density increases.

The energy density is sufficient to cause atmospheric molecules to dissociate, and their component atoms to become ionized. The vehicle thus descends in a superheated shroud of incandescent plasma. Plasma, known as the fourth state of matter has proportionality to pressure and temperature.

The formation of the pressure wave, therefore, also creates extreme temperatures. The plasma stream is electrostatically-charged too and causes intense local heating in the acute contours of the shuttle's body.

1.3.3.3) Process of re-entry

The space has altitude of 150 kms and a total velocity of 29000 kmph. A speed trim of about 300 kmph is sufficient to initiate descent. Shedding around one percent of the momentum of a vehicle might seem like a gentle touch on the brakes, but it's a complex operation for the shuttle. Small thrusters are sufficient to alter its attitude, but a reduction of speed requires the firing of relatively large rocket motors pointing forward, opposite to the sense of travel.

Thrusters flip the orbiter right over about its pitch axis, so that its tail now points towards the earth. The main engines are then fired for about twenty seconds. The thrusters fire again in a different configuration, rotating the craft on its yaw axis. It emerges from this sequence in the descent attitude, nose forward and slightly upward, and belly facing downward. This process utilizes all available fuel on the craft. At an altitude of around 120 km, the orbiter enters a discernable atmosphere. Though still extremely rarefied (containing little oxygen), there is now enough external matter to undergo ionization, and the plasma flare begins to form. From this point, the angle of attack is critical, and is maintained at 40 degrees by automatic and continuous thruster trims. Any shallower, and the orbiter will experience excessive lift and overfly its destination. Any steeper and it will burn up. At an altitude of 85 km, the flight surfaces of the orbiter become usable. Under automatic control, a series of four S-bend turns is now performed, with the craft banking through 80 degrees at the fullest extent of the roll. The object is to lose speed more quickly.

The enclosure of plasma is never complete over the shuttle and so there is always a communication maintained with the NASA space control. When the shuttle is still at an altitude of 40 kms it has speed of 10000 kmph.

Plasma flaring has ceased, and has now been replaced by reactive hypersonic flow. Drag on the craft increases greatly, and deceleration takes place more rapidly. The pilot takes control and reduces the speed to 4000 kmph into a stable supersonic regime by using airbrakes which become effective now. With still a 40 kms range from the runway, the pilot adjusts the nose of the shuttle in a landing direction and releases the landing gears (i.e. wheels).The speed of touchdown is 350 kmph. The parachutes are released and wheel brakes are employed to lower the speed to 150 kmph and the shuttle finally comes to a halt.

1.3.4) Reaction control systems (RCS)

The Reaction Control System (RCS) is composed of 44 small liquid-fueled rocket thrusters and their very sophisticated computerized (fly-by-wire) The RCS system provides the fine-pointing control of the Orbiter by the 12 primary and two vernier RCS rockets. It is used for attitude during re-entry along the pitch, roll, and yaw axes during all of the flight phases of launching, orbiting, and re-entry. It is used for station keeping in orbit. It monitors the conservation of limited fuel in spacecraft.

1.3.5) Pressurized cabin

The whole craft is pressurized at around 1 atm. There is an airlock which depressurizes the spacesuits before a walk in space and repressurizes before the astronomer enters the craft. The airlock mechanism doesn’t allow the craft to lose pressure to the outer space while the astronauts make movements from and to the space.

1.3.6) Propulsion

1.3.6.1) Simple Physics involved in rocket propulsion systems

In Earth’s Atmosphere

In a rocket engine some type of (usually) chemical reaction spits the burned rocket fuel out of the back of the rocket. Via this chemical reaction, the rocket exerts a strong backward force on the burned rocket fuel. According to Newton's third law the required reaction is that the burned rocket fuel exerts an equal forward force on the rocket. This force accelerates the rocket forward.

Outside Earth’s Atmosphere

An object's momentum is its mass multiplied by its velocity: momentum equals mass times velocity. Momentum, like velocity, is a vector quantity. It includes direction. If an object changes the direction of its motion, its velocity and momentum both change. The law of conservation of momentum applies only to isolated systems, which have no external forces acting on them. Momentum conservation states that the total momentum of an isolated system must remain constant. If the rocket and the fuel inside the rocket is an isolated system, then the total momentum of the rocket and fuel must remain zero as the rocket launches. When the rocket ignites, violent chemical reactions in the rocket fuel thrust the burned rocket fuel out the back of the rocket at a high rate of speed. This burned rocket fuel has a large backwards momentum. However the total momentum of the rocket fuel system must be conserved and remain zero. If the burned fuel has a backwards momentum, the rocket must have an equal forward momentum. The rocket must accelerate forward to get the needed forward momentum. The backward and forward momenta add up to zero because momentum is a vector. The two momenta have opposite signs. If the forward momentum is positive, the backward momentum is negative. The equal positive and negative numbers add to zero. The rocket has a forward momentum so that the rocket and fuel system keep the zero total momentum when the burned fuel has a backward momentum. These principles apply to any rocket from a toy water rocket to the launch of the space shuttle. They also apply to more than rocket propulsion. For example, a gun recoils when fired because of the same principles.

A) SRBs (SOLID ROCKET BOOSTERS)

They are located on either side of the rusty or orange-colored external propellant tank. The two SRBs, with their combined thrust of some 26 million Newton (about 5.8 million lb), provide most of the power for the first two minutes of flight. The SRBs take the space shuttle to an altitude of 45 km (28 mi) and a speed of 4,973 km/h (3,094 mph) before they are separated by the booster separator motors and fall back into the ocean to be retrieved, refurbished, and prepared for another flight. Each SRB produces 80% more liftoff thrust than one F-1 engine, the most powerful single-chamber liquid-fueled rocket engine ever flown.

B) SSMEs (SPACE SHUTTLE MAIN ENGINE)

It is manufactured by rocket dyne. A total of 42 reusable SSME engines have been part of the STS program, after each flight, the three SSMEs are removed from the Space Shuttle orbiter, inspected and refurbished in preparation for reuse on a subsequent flight.

After the boosters fall away, the three main engines of the orbiter continue to provide thrust .Three Space Shuttle Main Engines (SSMEs) are mounted on the Orbiter's aft fuselage in the pattern of an equilateral triangle. These engines are clustered at the rear end of the orbiter and have a combined thrust of almost 5.3 million Newton (almost 1.2 million lb).They use the liquid hydrogen and oxygen from the external fuel tank in earth’s atmosphere and use the liquid fuel in the craft in space. The space shuttle's liquid-propellant engines are the world's first reusable rocket engines. They fire for only eight minutes for each flight, just until the shuttle reaches orbit, and are designed to operate for 55 flights. The engines are very large—4.2 m (14 ft) long, and 2.4 m (8 ft) in diameter at the wide end of the cone-shaped nozzle at the rear of the orbiter. These three liquid-fueled engines can be swiveled 10.5 degrees vertically and 8.5 degrees horizontally by the hydraulic system during the rocket-powered ascent of the Orbiter in order to change the direction of their thrust.

C) OMS (ORBITAL MANEUVERING SYSTEMS)

Space shuttle’s main engines shut down as the ship approaches the altitude at which it will begin orbiting around Earth, known as the orbital insertion point. The Space Shuttle Orbital Maneuvering System, or OMS is a system of 44 rocket engines designed and manufactured by Aerojet for use on the space shuttle orbiter for orbital injection and modifying its orbit. It consists of a reaction control system(RCS) which uses fuel monomethylhydrazine (MMH), which is oxidized with nitrogen tetroxide (N₂O₄).RCS is clustered at the nose of the shuttle and either side of the tail. The orbital insertion point has to be tampered to facilate shuttle's important work of retrieving, launching, and repairing satellites in orbit.

D) EFT (EXTERNAL FUEL TANK)

They are the giant, cylindrical, external fuel tank, with a length of 47 m (154 ft) and a diameter of 8.4 m (27.5 ft), is the largest single piece of the space shuttle. It weight 27000kg without fuel. It contains the liquid hydrogen fuel and liquid oxygen oxidizer. It fuels the orbiter's three main engines or the SSMs which use 450 kgs of fuel each per second. During launch, the external tank also acts as a support for the orbiter and SRBs to which it is attached.. During lift-off and ascent it supplies the fuel and oxidizer under pressure to the three space shuttle main engines (SSME) in the orbiter. Unlike the SRBs external tanks can’t be re-used. After its 1.99 million liters (526,000 gallons) of fuel are consumed during the first 8.5 minutes of flight, the external tank is jettisoned from the orbiter and breaks up in the upper atmosphere.

1.3.7) Hydraulic Systems

The aft of the fuselage also houses three auxiliary power units (APU). The APUs burn hydrazine to provide hydraulic pressure for all of the hydraulic system, including the ones that point the three main liquid-fueled rocket engines, under computerized flight control. The hydraulic pressure generated is also used to control all of the Orbiter's "aero surfaces" (the elevons, rudder, air brake, etc.), to deploy the gear of the Orbiter, and to open and close the cargo bay's large main doors.

1.3.8) Reason for the space shuttle to remain stable earth’s orbit

The stability of the shuttle in an earth’s orbit is based on the principle of centripetal and centrifugal force. The craft has to maintain a critical velocity and altitude to prevent it from descending to the earth’s atmosphere under gravity. It has to move at a speed 30 times that of sound or approx. 8 kms/s.

1.3.9) Docking

At times the shuttles need to dock or join with artificial satellites or space station to update it or to replace its damaged component or add new sections or set up new aerials and solar panels. They join the satellites at previously made joint with the help of RMS.

2) Space events

Terminal Count

Extends from T minus 20 minutes through SRB ignition.

First Stage

Extends from SRB ignition through SRB separation.

Second Stage

Begins at SRB separation and extends through main engine cutoff and ET separation.

Ascent Abort Modes

Abort may become necessary if there is a failure that affects vehicle performance.

Return-to-Launch-Site

Designed to allow return of orbiter and crew to KSC launch site.

Transatlantic Landing

Available if a main engine fails after last RTLS opportunity, but before AOA can be accomplished.

Abort to Orbit

Used to boost the orbiter to a safe orbital altitude if it is impossible to reach the planned altitude.

Abort Once Around

Vehicle orbits the Earth once and lands at Edwards AFB or KSC.

Contingency Abort

Maintains orbiter integrity for in-flight crew escape if landing cannot be made.

Manual Thrust Vector Control

Substitutes inputs from RHC for automatic commands from Guidance.

Orbit Insertion

Following MECO, one or two propulsive thrusting periods move the vehicle to the desired orbital altitude

On Orbit

Guidance, navigation and control during orbit phase.

On-Orbit Checkout

The day before deorbit, the crew performs a checkout of systems used during entry.

Deorbit

Phase includes deorbit burn preparation through descent to 400,000 feet.

Entry

Phase begins at 400,000 feet and ends at touchdown.

3) Living in Space

3.1) Challenges in space

· Debris (rubbish) from previous space missions and micrometriods posses’ threat.

· Astronauts have to face highly accelerated ascent and descent.

· Basic needs as breathing, eating and drinking, elimination of body wastes, and sleeping.

· Microgravity.

3.2) Solutions

3.2.1) Protection against radiation and mechanical threats

Space vehicles usually have double hulls for protection against impacts. A particle striking the outer hull disintegrates and thus does not damage the inner hull. Usual Missions in earth orbit remain in naturally protected regions, such as the earth's magnetic field. Filters installed on spacecraft windows protect the astronauts from blinding ultraviolet rays.

3.2.2) Thermal Regulation

Aboard a spacecraft, temperatures climb because of the heat given off by electrical devices and by the crew's bodies. A set of equipment called a thermal control system regulates the temperature. The system pumps fluids warmed by the cabin environment into radiator panels, which discharge the excess heat into space.

3.2.3) Microgravity

At the altitude of shuttle orbit the gravity is just a bit less than that of earth but the velocity of the shuttle around the earth counteract the gravitational force and create weightlessness.

Fuel does not drain from tanks in microgravity, so it must be squeezed out by high-pressure gas. Hot air does not rise in microgravity, so air circulation must be driven by fans. About half of all space travelers suffer from persistent nausea, sometimes accompanied by vomiting. Drugs to prevent motion sickness can provide some relief for the symptoms of space adaptation syndrome. Microgravity also confuses an astronaut's vestibular system--that is, the organs of balance in the inner ear--by preventing it from sensing differences in direction. The vestibular system is responsible for sensing the orientation of our body and functions under gravity. Muscles go week and the heart becomes weak because of pumping blood in microgravity. The astronauts use treadmills, bikes to remain healthy. The space program also demineralizes their bones due to the absence of stress and strain.

3.2.4) Basic Needs

· Breathing: A tank containing mixture of nitrogen and oxygen. Fans circulate air through the cabin and over containers filled with pellets of a chemical called lithium hydroxide. These pellets absorb carbon dioxide from the air. Charcoal filters help control odours.

· Eating and Drinking: Astronomers eat ready to eat foods which have high nutritive value. Salt and pepper are available but only in a liquid form and not in a powder form because There is a danger they could clog air vents, contaminate equipment or get stuck in an astronaut's eyes, mouth or nose.

Drinking water is obtained from the dry cell used for providing electric supply to the craft. Dehumidifiers recycle the water exhaled by the astronauts and put it into use in the thermal control system.

· Eliminating body wastes: On small spacecraft, crew members use funnels for urine and plastic bags for solid wastes. While working outside the spacecraft, astronauts wear special equipment to contain body wastes.

3.3) Space Suits

The suit is made from many layers of flexible, airtight materials, such as nylon and Teflon. It is able to keep its occupant alive for 7 hours in space. On the EVA (Extra Vechiluar Activity) is facilated by the spacesuit. The spacesuits should be able to perform functions as-

· Life support Systems provide Breathable cool oxygen at 32kPa ,remove odors humidity and CO₂,maintains internal spacesuits pressure a little below 1 atm as lower pressure allows mobility, provides communication means among the occupants

· Unlike earth where most heat is transferred by convection, space astronauts lose or gain heat by thermal radiation and conduction. Since the temperature varies a lot in the shady and non shady areas in space thus the space suits are made of highly insulating material. The Apollo/Skylab A7L suit included eleven layers in all: an inner liner, a liquid cooling and ventilation garment, a pressure bladder, a restraint layer, another liner, and a thermal micrometeoroid garment consisting of five aluminized insulation layers and an external layer of white Ortho-Fabric.

· Storage bags for human faeces and excreta which are made up of Maximum Absorbency garment.

· It should be able to protect the occupant from ultraviolet radiation, particle radiation, and micrometeoroids provided by a Thermal Micrometeoroids Cloth.

Scripted and Edited by Tathagat Nawadia

(PowerPoint Presentation of the Project Mission Spacecraft coming soon)

Diplomacy’s Meltdown

2011-02-22T21:15:00.000+05:30

When it comes to climate change, developing nations aren't the laggards.

Bad news on climate diplomacy continues to pile up. A spate of

studies has shown over the past year that even if countries honored

the pledges they made in the Copenhagen Accord in December

2009, warming would still blow past the agreed limit of

two degrees. Most other elements of the accord, which was designed

to keep momentum until a formal climate treaty could be

reached, are under shadow as well. Plans by rich nations to add

$100 billion of new money in the next decade to help developing

countries cut emissions are

evaporating. And diplomatic

talks on a formal treaty are

moving backward.

Why is diplomacy stalled?

The conventional wisdom

holds that developing countries

are the main villains.

Few will agree to sign binding

and verifiable commitments

to control emissions.

The reality, however, is different.

China, India, Brazil

and other developing countries

are actually the leaders

in the effort to curb emissions.

But most of what they

are doing is not visible, because it is rooted in local concerns,

such as urban air pollution, rather than fear of global warming.

China, the world’s biggest emitter, is making the world’s biggest

effort to check growth in its pollution. Last year marks the

end of a five-year massive program to boost the country’s energy

efficiency, and plans are in place for another major push

over the next five years. China is building more nuclear plants

(zero-emissions) and ultrasupercritical coal plants, which are

much more efficient than conventional plants and thus less polluting,

than the rest of the world combined. China is much

more in the news for its big push on renewable power, but its

investment in advanced coal and nuclear power will have a

much bigger impact on warming emissions. Across the Chinese

economy, efficiency has become a watchword. It even factors

into how the Chinese Communist Party promotes its officials.

India is in the midst of a similar push. Most new coal-fired

power plants are more efficient than the older technologies

that used to be standard equipment. A program to build commercial

nuclear power is gathering steam, thanks in

part to a deal brokered by the U.S. to give India access

to Western technology and fuel. India, China

and many other countries are poised to rely more

heavily on natural gas, which has less than half thewarming emissions of coal. And India is embarking on one of

the world’s most ambitious solar energy programs.

Developing nations are also making progress on curbing deforestation,

which accounts for perhaps one seventh of all

greenhouse gas emissions. Brazil, owner of the planet’s largest

tropical forests, has radically improved enforcement of its

forest laws—contributing

to the lowest

rate of deforestation

in that country in two decades. Indonesia is crafting policies—in

part with external help

from Norway and other

wealthy countries—to cut

its total emissions, mainly

by slowing deforestation.

The sum of these efforts

in developing countries will

reduce growth in warming

emissions by billions of metric

tons of warming gases

per year over the coming decade.

That dwarfs the total

cuts by Westerns nations to

comply with the Kyoto Protocol,

which amounted to, at

most, a few hundred million

tons. Developing countries

have most of the leverage for further cuts. They now account

for half the emissions of warming gases—and rising.

Developing countries have resisted enshrining their programs

into binding international law because most of these initiatives

are rooted in national goals, such as controlling local

pollution and increasing the value of forests, which makes

them skittish about foreign commitment and monitoring.

Breaking the gridlock on global warming, which will make it

easier for these countries to do even more in the future, will require

less intrusive approaches, such as flexible commitments

and peer review.

The initiatives under way in developing countries will not

be enough, of course. Strict treaties with deep cuts in emissions,

monitoring and penalties will be required for all nations. But

that is a long way off, and the current track is making it harder

to build the credibility and trust that will be needed. The rich

countries focus on bold goals—such as stopping warming at

two degrees or giving away $100 billion in financial support—

with no relation to what they can really implement.

That makes developing countries unsure which commitments

are genuine. Smaller initiatives aligned

with what countries can really honor would be a

smarter way forward.

2011-02-20T10:31:00.000+05:30

Giant Planets Orbiting Faraway Stars

2011-02-20T08:58:00.001+05:30

No doubt humans have struggled with the question
of whether we are alone in the universe since
the beginning of consciousness. Today, armed
with evidence that planets do indeed orbit other
stars, astronomers wonder more specifically: What are those
planets like? Of the 100 billion stars in our Milky Way galaxy,
how many harbor planets? Among those planets, how
many constitute arid deserts or frigid hydrogen balls? Do
some contain lush forests or oceans fertile with life?
For the first time in history, astronomers can now address
these questions concretely. During the past two and a half
years, researchers have detected eight planets orbiting sunlike
stars. In October 1995 Michel Mayor and Didier Queloz
of Geneva Observatory in Switzerland reported finding the
first planet. Observing the star 51 Pegasi in the constellation
Pegasus, they noticed a telltale wobble, a cyclical shifting of
its light toward the blue and red ends of the spectrum. The
timing of this Doppler shift suggests that the star wobbles
because of a closely orbiting planet, which revolves around
the star fully every 4.2 days—at a whopping speed of
482,000 kilometers (299,000 miles) an hour, more than
four times faster than Earth orbits the sun.
Another survey of 107 sunlike stars, performed by our
team at San Francisco State University and the University of
California at Berkeley, has turned up six more planets. Of
those, one planet circling the star 16 Cygni B was independently
discovered by astronomers William D. Cochran and
Artie P. Hatzes of the University of Texas McDonald Observatory
on Mount Locke in western Texas.
Detection of an eighth planet was reported in April 1997,
when a nine-member team led by Robert W. Noyes of
Harvard University detected a planet orbiting the star Rho
Coronae Borealis. A ninth large object, which orbits the star
known by its catalogue number HD114762, has also been
observed—an object first detected in 1989 by astronomer
David W. Latham of the Harvard-Smithsonian Center for
Astrophysics and his collaborators. But this bulky companion
has a mass more than 10 times that of Jupiter—large,
though not unlike another large object discovered around
the star 70 Virginis, a similar object with a mass 6.8 times
that of Jupiter. The objects orbiting both HD114762 and 70
Virginis are so large that most astronomers are not sure
whether to consider them big planets or small brown dwarfs,
entities whose masses lie between those of a planet and a star.
Detecting Extrasolar Planets
Finding extrasolar planets has taken a long time because
detecting them from Earth, even using current technology,
is extremely difficult. Unlike stars, which are fueled
by nuclear reactions, planets faintly reflect light and emit
thermal infrared radiation. In our solar system, for example,
the sun outshines its planets about one billion times in visible
light and one million times in the infrared. Because of the distant
planets’ faintness, astronomers have had to devise special
methods to locate them. The current leading approach is the
Doppler planet-detection technique, which involves analyzing
wobbles in a star’s motion.
Here’s how it works. An orbiting planet exerts a gravitational
force on its host star, a force that yanks the star around
in a circular or oval path—which mirrors in miniature the
planet’s orbit. Like two twirling dancers tugging each other
in circles, the star’s wobble reveals the presence of orbiting
planets, even though we cannot see them directly.
The trouble is that this stellar motion appears very small
from a great distance. Someone gazing at our sun from 30
light-years away would see it wobbling in a circle whose
radius measures only one seventh of one millionth of one degree.
In other words, the sun’s tiny, circular wobble appears
only as big as a quarter viewed from 10,000 kilometers away.
Yet the wobble of the star is also revealed by the Dopplereffect of the starlight. As a star sways to and fro relative to
Earth, its light waves become cyclically stretched, then compressed—
shifting alternately toward the red and blue ends of
the spectrum. From that cyclical Doppler shifting, astronomers
can retrace the path of the star’s wobble and, from
Newton’s law of motion, compute their masses, orbits and
distances from their host stars. The cyclical Doppler shift
itself remains extremely tiny: stellar light waves shrink and
expand by only about one part in 10 million because of the
pull of a large, Jupiter-like planet. The sun, for example,
wobbles with a speed of only about 12.5 meters per second,
pivoting around a point just outside its surface. To detect
planets around other stars, measurements must be highly
accurate, with errors in stellar velocities below 10 meters
per second.
Using the Doppler technique, our group can now measure
stellar motions with an accuracy of plus or minus three
meters per second—a leisurely bicycling speed. To do this,
we use an iodine absorption cell—a bottle of iodine vapor—
placed near a telescope’s focus. Starlight passing through the
iodine is stripped of specific wavelengths, revealing tiny shifts
in its remaining wavelengths. So sensitive is this technique
that we can measure wavelength changes as small as one part
in 100 million.
As recorded by spectrometers and analyzed by computers,
a star’s light reveals the telltale wobble produced by its orbiting
companions. For example, Jupiter, the largest planet in
our solar system, is one thousandth the mass of the sun.
Therefore, every 11.8 years (the span of Jupiter’s orbital
period) the sun oscillates in a circle that is one thousandth
the size of Jupiter’s orbit. The other eight planets also cause
the sun to wobble, albeit by smaller amounts. Take Earth,
having a mass 1/318 that of Jupiter and an orbit five times
closer: it causes the sun to move a mere nine centimeters
a second.
Yet some uncertainty about each extrasolar planet’s
mass remains. Orbital planes that astronomers view
edge-on will give the true mass of the planet. But
tilted orbital planes reduce the Doppler shift because of
a smaller to-and-fro motion, as witnessed from Earth.
This effect can make the mass appear smaller than it
is. Without knowing a planet’s orbital inclination,
astronomers can compute only the least possible mass
for the planet; the actual mass could be larger.
Thus, using the Doppler technique to analyze light
from about 300 stars similar to the sun—all within
50 light-years of Earth—astronomers have turned up
eight planets similar in size and mass to Jupiter and
Saturn. Specifically, their masses range from about a
half to seven times that of Jupiter, their orbital periods
span 3.3 days to three years, and their distances from
their host stars extend from less than one twentieth
of Earth’s distance to the sun to more than twice that
distance [see illustration on opposite page].
To our surprise, the eight newly found planets
exhibit two unexpected characteristics. First, unlike
planets in our solar system, which display circular
orbits, two of the new planets move in eccentric, oval
orbits around their hosts. Second, five of the new
planets orbit very near their stars—closer, in fact, than
Mercury orbits the sun. Exactly why these huge
planets orbit so closely—some skim just over their
star’s blazing coronal gases—remains unclear. These
findings are mysterious, given that the radius of Jupiter’s
orbit is five times larger than that of Earth. These
observations, in turn, provoke questions about our own
solar system’s origin, prompting some astronomers to
revise the standard explanation of planet formation.
Reconsidering How Planets Form
What we have learned about the nine planets in our
own solar system has constituted the basis for the
conventional theory of planet formation. The theory
holds that planets form from a flat, spinning disk of gas and
dust that bulges out of a star’s equatorial plane, much as
pizza dough flattens when it is tossed and spun. This model
shows the disk’s material orbiting circularly in the same
direction and plane as our nine planets do today. Based on
this theory, planets cannot form too close to the star, because
there is too little disk material, which is also too hot to coalesce.
Nor do planets clump extremely far from the star, because
the material is too cold and sparse.
Considering what we now know, such expectations about
planets in the rest of the universe seem narrow-minded.
The planet orbiting the star 47 Ursae Majoris in the Big
Dipper constellation stands as the only one resembling what
we expected, with a minimum bulk of 2.4 Jupiter-masses
and a circular orbit with a radius of 2.1 astronomical units
(AU)—1 AU representing the 150-million-kilometer distance
from Earth to the sun. Only a bit more massive than Jupiter,
this planet orbits in a circle farther from its star than Mars
does from the sun. If placed in our solar system, this new
planet might appear as Jupiter’s big brother.
But the remaining planetary companions around other
stars baffle us. The two planets with oval orbits have eccentricities of 0.68 and 0.40. (An eccentricity of zero is a perfect
circle, whereas an eccentricity of 1.0 is a long, slender oval.)
In contrast, in our solar system the greatest eccentricities
appear in the orbits of Mercury and Pluto, both about 0.2;
all other planets show nearly circular orbits (eccentricities
less than 0.1).
These eccentric orbits have prodded astronomers to scratch
their heads and revise their theories. Within two months of
the first planet sighting, theorists hatched new ideas and adjusted
the standard planet formation theory.
For instance, astronomers Pawel Artymowicz of the University
of Stockholm and Patrick M. Cassen of the National
Aeronautics and Space Administration Ames Research
Center recalculated the gravitational forces at work when
planets emerge from disks of gas and dust seen swirling
around young, sunlike stars. Their calculations show that
gravitational forces exerted by protoplanets—planets in the
process of forming—on the gaseous, dusty disks create alternating
spiral “density waves.” Resembling the “arms” of
spiral galaxies, these waves exert forces back on the forming
planets, driving them from circular motion. Over millions of
years, planets can easily wander from circular orbits into eccentric,
oval ones.
A second theory also accounts for large orbital eccentricities.
Suppose, for instance, that Saturn had grown much
larger than it actually is. Conceivably, all four giant planets
in our solar system—Jupiter, Saturn, Uranus and Neptune—
could have swelled into bigger balls if our original protoplanetary
disk had contained more mass or had existed
longer. In this case, the solar system would contain four
superplanets, exerting gravitational forces on one another,
perturbing one another’s orbits and causing them to intersect.
Eventually, some of the superplanets might be gravitationally
thrust inward,others outward, an unlucky few even ejected from the planetary system.Like balls ricocheting
on a billiards table,the scattered giant planets might adopt extremelyeccentric orbits, as we
now observe for three of the new planets. Interestingly,this billiards model for eccentric planets shows that we should beable to detect the massive planets causing eccentric orbits—planets perhaps
orbiting farther out than the planets we have detected thus far. A variation on this theme suggests that a companion
star, rather than other
planets, might gravitationally
scatter planet
orbits.
The most bizarre of the
new planets are the four
so-called 51 Peg planets,
which show orbital periods
shorter than 15 days. The four members of this class are
51 Peg itself, Tau Bootis, 55 Cancri and Upsilon Andromedae,
which have orbital periods of just 4.2, 3.3, 14.7 and 4.6 days,
respectively.
These orbits are all small, with radii less than one tenth the
distance between Earth and the sun—indeed, less than one
third of Mercury’s distance from the sun. Yet these planets
are as big as, or bigger than, the largest planet in our solar
system. They range in mass from 0.44 of Jupiter’s mass for
51 Peg to 3.64 of Jupiter’s mass for Tau Bootis. Their
Doppler shifts suggest that these planets orbit in circles.
Mysterious 51 Pegasi–Type Planets
The 51 Peg planets defy conventional planet formation
theory, which predicts that giant planets such as Jupiter,
Saturn, Uranus or Neptune would form in the cooler
outskirts of a protoplanetary disk, at least five times the
distance from Earth to the sun.
To account for these planetary oddities, a revised planet
formation theory is making the rounds in theorists’ circles.
Astronomers Douglas N. C. Lin and Peter Bodenheimer, both
of the University of California at Santa Cruz, and Derek C.
Richardson of the University of Washington extend the
standard model by arguing that a young protoplanet precipitating
out of a massive protoplanetary disk will carve a
groove in the disk, separating it into inner and outer sections.
According to their theory, the inner disk dissipates energy
because of dynamical friction, causing the disk material and
the protoplanet to spiral inward and eventually plunge into
the host star.
A planet’s salvation stems from the young star’s rapid
rotation, spinning every five to 10 days. Approaching its star,a planet would cause tides on the star to rise, just as the
moon raises tides on Earth. With the young star rotating
faster than the protoplanet orbiting the star, the star would
tend to sprout a bulge whose gravity would tug the planet
forward. This effect would tend to whip the protoplanet into
a larger orbit, halting its deathly inward spiral.
In this model, the protoplanet hangs poised in a stable
orbit, delicately balanced between the disk’s drag and the
rotating star’s forward tug. Even before the discovery of the
51 Peg planets, Lin predicted that Jupiter should have spiraled
into the sun during its formation. If this were so, then
why did Jupiter survive? Perhaps our solar system contained
previous “Jupiters” that did indeed spiral into the sun, leaving
our Jupiter as the sole survivor.
Why, we wonder, does no large 51 Peg–like planet orbit
close to our sun? Perhaps Jupiter formed near the end of our
protoplanetary disk’s lifetime. Or the protoplanetary disk
may have lacked enough gas and dust to exert sufficient
tidal drag. Perhaps protoplanetary disks come in a wide
range of masses, from a few Jupiter-masses to hundreds of
Jupiter-masses. In that case, the diversity of new planets
may correspond to different disk masses or disk lifetimes,
perhaps even to different environments, including the presence
or absence of nearby radiation-emitting stars.
On the other hand, astronomer David F. Gray of the University
of Western Ontario in Canada has challenged the existence
of the 51 Peg planets altogether. Gray argues that the alleged
planet-bearing stars are themselves oscillating—almost like
wobbling water balloons. In his view, the cyclical Doppler
shifts in these stars stem from inherent stellar wobbles, not
planets tugging at stars.
Armed with new data, astronomers now largely dismiss the
existence of the oscillations. The strongest argument against
the oscillations stems from the single period and frequency
seen in the Doppler variations from the star. Most oscillating
systems, such as tuning forks, display a set of harmonics, or
several different oscillations occurring at different frequencies,
rather than just one frequency. But the 51 Peg stars show
only one period each, quite unlike harmonic oscillations.
Moreover, ordinary physical models predict that the
strongest wobbles would occur at higher frequencies than
those of the observed oscillations of these stars. In addition,
the 51 Peg stars show no variations in brightness, suggesting
that their sizes and shapes are not changing.
Planetary Comparisons
Although we are tempted to compare the eight new
planets with our own nine, the comparison is, unfortunately,
quite challenging. No one can draw firm
conclusions from only eight new planets. So far our ability
to spot other types of planets remains limited. At present,
our instruments cannot even detect Earth-size companions.
Although the extrasolar planets found to date have orbital
periods no longer than three years, this finding does not
necessarily represent planetary systems in general. Rather it
arises from the fact that astronomers have searched for
other planets with better techniques for only about a decade. With more time and improved Doppler precision,
more planets with longer orbital periods may be found.
Curiously, finding these new planets proves that our own
history could easily have played out quite differently. Suppose
that gravitational scattering of planets occurs commonly in
planetary systems. We see in our own solar system evidence
that during its first billion years, planetesimals—fragmentary
bodies of rock and ice—hurtled through space. Our cratered
moon and Uranus’s highly tilted axis—nearly perpendicular
to the axes of all its neighbors—show that collisions were
common, some involving planet-size objects. The neatly
carved orbits of our now stable solar system emerged from
the collision-happy orbits of its youth.
We should consider ourselves lucky that Jupiter ended up
in a nearly circular orbit. If it had careened into an oval orbit,
Jupiter might have scattered Earth, thwacking it out of the
solar system. Without stable orbits for Earth and Jupiter, life
might never have emerged.
The Future of Planet Hunting
In July 1996 we began a second Doppler survey of 400
stars, using the 10-meter Keck telescope at Mauna Kea
Observatory in Hawaii. Mayor and Queloz of Geneva
Observatory recently tripled the size of their Northern Hemisphere
Doppler survey to about 400 stars, and soon they will
begin a Southern Hemisphere survey of 500 more stars.
Within the next year, Doppler surveys of several hundred
additional stars will begin at the nine-meter Hobby-Eberly
Telescope located at McDonald Observatory.
By the year 2000 two Keck telescopes on Mauna Kea and
a binocular telescope at the University of Arizona will become
optical interferometers, precise enough to image extrasolar
planets. NASA plans to launch at least three spaceborne
telescopes to detect planets in infrared light.
One proposed NASA space-based interferometer,
a second-generation telescope known
as the Terrestrial Planet Finder, should obtain
pictures of candidate habitable planets orbiting
distant stars. Arguably the greatest telescope
ever conceived, Planet Finder could spot other
Earths, starting in about 2010. Using a
spectrometer, it could analyze light from faroff
planets to determine the chemical makeup
of their atmospheres—data to determine if
biological activity is proceeding. This monumental,
spaceborne telescope would span a
football field and sport four huge mirrors.
Drawing from the data on planets found so
far, we believe other planets orbit similar stars,
many the size of Jupiter, some the size of Earth.
It may be that as many as 10 percent of all
stars in our galaxy host planetary companions.
Based on this estimate, 10 billion planets
would exist in our Milky Way galaxy alone.
Seeking the ideal Earth-like planet on which
life could flourish, astronomers will search for
planets that are neither too cold nor too hot,
temperate enough to sustain liquid water to
serve as the mixer and solvent for organic
chemistry and biochemistry. Planets with the
perfect blend of molecular constituents
orbiting at just the right distance from the sun
enjoy what astronomers call a “Goldilocks” orbit.
Seeing such a planet would spawn an endless stream of
questions: Does its atmosphere contain oxygen, nitrogen,
and carbon dioxide, like Earth’s, or sulfuric acid and CO2,
the deadly combination on Venus? Is there a protective
ozone layer, or is the surface scorched by harmful ultraviolet
rays? Even if a planet has oceans, does the water have a pH
neutral enough to permit cells to grow?
There may even exist some other biology that thrives on
sulfuric acid—even starves without it. Indeed, if primitive life
does arise on another Earth, does it always evolve toward
intelligence, or is our human technology some fluke of
Darwinian luck? Are we humans a rare quirk of nature,
destined to appear on Earth-like planets only once in a
universe that otherwise teems with primitive life?
Amazing as it seems, answers to some of these questions
may arise during our lifetimes, using tools such as telescopes
already in existence or on the drawing board. We can only
barely imagine what the next generation will see in our
reconnaissance of the galactic neighborhood. Human
destiny lies in exploring the galaxy and finding our roots,
biologically and chemically, out among the stars.