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1St Cover Sep Issue.Indd

1St Cover Sep Issue.Indd

SUSHEELA SRINIVAS

The world looks forward to ’s

TORY communication to unravel and demystify the S

hidden secrets of our . All images courtesy NASA OVER OVE C

HE fi h planet in our solar system, TJupiter, has always fascinated astronomers and space agencies. And rightly so – with its massive size (almost twice as much as all the other planets put together), its light and dark bands, the at the poles, its four distinct moons and the enigmatic gaseous state – all make it worth the watch. NASA’s mission to explore the planet in depth has been massive too. While Pioneer and Voyager, on their interstellar missions, skimmed the planet and sent back spectacular images, the spacecra was exclusively commissioned in 1989 to reach and study its moons. A probe was released to the surface in 1995 from Galileo. Flying by close to and , two of the four moons of Juno blasts off on Jupiter, it sent amazing information about its journey to Jupiter them and the existence of sub-surface aboard the –V 551 oceans on them. Its mission completed, rocket the spacecra disintegrated in Jupiter’s atmosphere. ScienceSSciiencn e Reporter,RReportter SESEPTEMBERPTEMBER 20201616 14 COVER STORY

Jubilation as tracking centre records the successful locking of Juno into the orbit of Jupiter

On 5 August 2011, another spacecra system of transmi ers and receivers planets. Galileo was designed to study was launched from NASA’s base in that communicate with interplanetary the moons in detail. Moreover, it could , USA. Called Juno, the Jupiter- spacecra . not approach the planet nearer to record bound spacecra was carried aboard the There was jubilation all around in the studies; Atlas–V 551 rocket. The Juno mission the tracking centre on 4 July 2016. The In what way is the Juno probe is part of the monitors in the tracking centre recorded diff erent from the earlier ones? Why is managed at NASA’s Marshall Space the successful locking of Juno into the this mission so special and signifi cant? Flight Centre in Huntsville, Alabama. orbit of Jupiter. NASA released a video Well, Juno scores brownie points on Its mission was to reach the bright, big consisting of time lapse images that several accounts. planet and study it in much more detail. clearly show the four in Firstly, most spacecra s are designed The target distance: around 588 million tandem as recorded by Juno. to be powered by radioactive energy to kilometres (588,000,000 km at its closest accommodate the continuity of power to ). A Special Mission supply in the absence of sunlight. The spacecra manufactured by Jupiter has been studied earlier too. In the However, Juno deviates from this in that it at an approximate cost previous eight missions, only Galileo was is a completely solar-powered spacecra . of 1.1 billion dollars (2011), is managed an exclusive spacecra sent to the planet, Secondly, Juno’s aim is to study by JPL – Jet Propulsion Laboratory at while all others were fl yby operations Jupiter’s core, presence of water in its the Institute of Technology – – that is, fl ying past and returning or, atmosphere and the formation of the for NASA. JPL also supervises NASA’s assists that is, taking Jupiter’s . These studies will throw Deep , a worldwide gravity to propel further to the target light on various theories. Juno will study in detail the evolution of the planet and other mysteries hidden in its core. This will help us gain more into the way our solar system was formed; it will give us clues as to how this planet has changed in the duration of 4.6 billion years – the life of our solar system so far. Thirdly, Juno will take a deep look at the fascinating auroras of Jupiter. This is a highly risky endeavour as it involves intense magnetic fi elds and currents. Juno’s technology has to withstand this Galileo extreme environment for around 20 spacecraft Jupiter exposures before degrading. www.jpl..gov was sent Fourthly, Juno is fi ed with a special exclusively to camera called JunoCam, made as an interactive module and available to the Jupiter public. NASA has provided the means to track JunoCam’s positioning in such

15 Science Reporter, SEPTEMBER 2016 COVER STORY

National Aeronautics and Space Administration

Built To Withstand Intense Radiation Environments

WHAT PROBLEMS DOES INTENSE WHY DOES JUPITER HAVE SUCH IN- EARTH RADIATION CAUSE? TENSE RADIATION BELTS? • Spacecraft and instrument degradation • Very strong magnetic fi eld • Electric charging of the spacecraft • Jupiter’s magnetosphere extends out 100 • Noise from particles hitting detectors Jupiter radii on the -facing side-Earth’s is only 10 Earth radii • In addition to the , Io’s volcanic activity constantly releases gas into the RADIATION magnetosphere, which gets ionized and CHALLENGE: energized, adding to the radiation EARTH Several instruments RADIATION JUPITER practiced making CHALLENGE: RADIATION measurements in Earth’s SPACE BELTS magnetosphere Radiation from…. • Solar energetic particles • Cosmic rays from outside the solar system RADIATION CHALLENGE: JUPITER WHAT PROTECTS JUNO FROM RADIATION EFFECTS? • Very intense radiation belts • Detectors and their electronics are built to withstand radiation • Particles trapped in the belts are • Most electronics shielded in ~1/2-inch thick vault so fast they spiral from top to • On the outside of the spacecraft, the star tracker’s camera is bottom in only a few seconds about 4x heavier than even the biggest standard star trackers • These particles are moving at due to extra shielding nearly the ! • Orbit is designed to avoid most intense pockets of radiation

www.nasa.gov

Juno’s aim is to study Jupiter’s core, presence of water in its atmosphere and the formation of the magnetosphere. These studies will throw light on various theories. Juno will study in detail the evolution of the planet and other mysteries hidden in its core. a way that any enthusiast can vote and JUNO’JOURNAL decide which parts of the surface can be photographed – just by using the Internet Launch: 5 August 2011 Speed on orbit: 0.17 km/sec and following NASA’s instructions on its website. Deep Space Exercises: Orbit height: 4300 km August/ September 2012 In orbit: 37 orbits spanning Great Challenges Earth fl yby assist ( or 20 months As Juno embarks on a mission to record a slingshot manoeuvre): the various aspects of Jupiter, it is fraught October 2013 with extreme conditions to be overcome. End of Mission (self-destruction): Being gaseous in nature, Jupiter Jupiter Arrival: July 2016 February 2018 off ers no solid base for probes to land on it. This is a big hurdle as any probe sent

Science Reporter, SEPTEMBER 2016 16 COVER STORY APT AND INTERESTING According to Roman mythology, Juno (also known as goddess Hera) is Jupiter’s (also known as Zeus) wife, and she was capable of seeing through clouds which Jupiter surrounded himself with. The primary mission of Juno is to look into the gaseous atmosphere and the clouds surrounding Jupiter. Very apt, indeed! Aboard Juno are three fi gurines represenƟ ng: Galileo, the astronomer who found Jupiter’s moons, he holds a replica of planet Jupiter and a telescope; Juno herself holding a magnifi er, symbolising the search for truth; and Jupiter, holding a bolt, signifying the intense radiaƟ ons around the planet. The has donated a plaque carrying an inscripƟ on that states the original words of Galileo Juno – Built to withstand as he discovered and presented to the world the presence of Jupiter’s moons. NUMBERS SIGNIFICANT TO JUNO This fi nding broke the then understanding that Earth was the centre of the universe. 3 – The number of solar wings (panels) which provide the power to the equipment. 9 – Nine instrument units will be recording the planet from its core to the atmosphere. to the rotating parts of the spacecra and 20 – Juno will orbit Jupiter for a period of 20 months before plunging into the harsh probes. Electrical arcing o en occurs atmosphere of the planet and destroying itself. between rotating and non-rotating parts 32 – Juno will make 32 polar orbits around Jupiter during its mission. causing system failure. Earlier probes faced these radiations and a lot of data 5000 – This is the closest distance Juno will approach the planet’s atmosphere to make was lost. its studies. All these hurdles can cause severe 588 million – The target distance of Juno was 588 million km as per requirement. damage to Juno by making it highly electrically charged. This aff ects the 2.8 billion – Juno had to travel a distance of 2.8 billion km to reach Jupiter. The route functioning of the spacecra , disrupting taken was a circuitous one as the engines were not powerful enough to launch Juno the working of the electronics and directly. It had to take the Earth’s gravity assistance and was sling-shot into outer recording equipment. Additionally the space. noise generated by the hi ing particles deep into its atmosphere will be crushed radiations. Juno’s protective shield has to rapidly degrades the functioning of the and destroyed due to the intense pressure withstand these radiations too. equipment. of the atmosphere surrounding it. • Jupiter’s magnetosphere: The sheer Travelling into deep space and close size of this gigantic planet has contributed Built to Withstand to Jupiter, which no other spacecra to a strong magnetosphere that covers a To overcome this situation, Juno has been has done before, causes the spacecra distance equal to nearly 100 times the fi ed with a specially designed electronic to be exposed to intense radiations. radius of the planet. In addition, its armour – a vault to protect its main The radiations encountered are in three moon Io is primarily volcanic in nature computer and recording instrument. A diff erent positions: spewing gaseous ma er into the planet’s 181 kilogram, half inch thick, titanium • Earth radiation: Caused due to the magnetosphere. These high intensity radiation shield, known as the electronic magnetosphere of the earth as the expulsions cause ionization adding to the radiation shield, is employed to protect spacecra vaults into . Many intensity of the magnetosphere. the system from the inevitable radiations. of these conditions are well studied and Jupiter’s radiation belt is so strong The radiation shield adds to the bulk and simulated for Juno to withstand. Juno that many particles trapped in it spiral weight of the spacecra so much so that overcame these. at the speed of light travelling from top the external camera, called the star tracker • Inter space radiation: The solar to bo om within a few seconds. These camera of the spacecra , is four times particles, random space objects and projectiles can pose a severe challenge to heavier than the conventional tracker cosmic rays from outside the solar system the spacecra . camera. are all travelling at high speeds, acting The radiations on Jupiter are so Moreover the detectors and as projectiles and cause the interstellar intense that they can cause severe damage electronics are upgraded and of superior

17 Science Reporter, SEPTEMBER 2016 COVER STORY Keeping the tradition of deep- space missions, Juno has time only till February 2018 before it has to destroy itself by deorbiting. This is in order to prevent any contamination from Earth (in the form of hidden bacteria or microbes on the spacecraft) that may unintentionally be present and carried into space by a defunct Juno captured this image on July 10, 2016, less than a week after entering orbit around Jupiter. Juno spacecraft. was about 2.7 million (4.3 million kilometers) from Jupiter when it took the picture. quality to withstand temperatures and Mostly made up of and AYLOAD NSTRUMENTS radiations be er than the currently , another interesting aspect of P I BOARD UNO available. Juno also gets assistance from Jupiter are the impressive light and dark A J the carefully designed orbit which avoids bands, created by strong east-to-west : This set of instruments the intense radiation pockets. winds of its atmosphere. The light white fi Ʃ ed at the mouth of the hexagonal clouds comprise of crystalline frozen body will record and study the gravity fi elds and deep core analysis of the Mission Requirements . Juno is programmed to make an extensive study of the bands while planet. Despite the earlier missions, Jupiter still orbiting Jupiter. MAG: A vector fi Ʃ ed to remains enigmatic. Due to its gaseous Juno’s information and recordings, the Ɵ p of the wing spans, it will record state, and a probable liquid core, a lot has the magneƟ c fi eld structure of Jupiter. to be revealed about this giant planet. As especially of the water content in the MWR: A six-wavelength Juno approaches the clouds over Jupiter atmosphere will throw light on the radiometer will be used to record for it will peer into the gaseous atmosphere. presence of and hence the theory atmospheric sounding and composiƟ on. The studies will also reveal if Jupiter of formation – that is, whether the current has a solid core. Jupiter is such a huge theory is supported or new theories JADE, JEDI and : These ball of raging gases, that it can easily have to be determined. Knowing about and energeƟ c parƟ cle detectors will be misunderstood for another Sun. The the original form of water will help us especially come to use in the study on its surface is blazing a understand be er how planets were of Auroras. Along with that they will gas which is big enough to gobble up the originally formed. In addition it may also sample and study the way the earth. A critical and close up view of the throw more light on the evolution of the magnetosphere is connected to the planet will reveal a lot of mysteries about solar system. atmosphere on Jupiter by sampling the formation of the solar system. We look to Juno to answer all these the electric fi elds, plasma waves and surrounding parƟ cles. While probing deep into the core questions. of Jupiter, it may reveal the way the UVS and JIRAM: These Ultra violet and intense magnetic fi eld is created. This Juno – Exploring Jupiter Infra-red range Spectrometers will be used for imagery. magnetosphere concentrates at the poles The Juno mission is divided into 13 causing the famous Jovian Auroras. One phases from launch to end-of-mission. JunoCam: This colour camera is the fi rst critical and important responsibility of This covers the pre-launch, deep space of its kind fi Ʃ ed to give an interacƟ ve Juno is the study of the . Unlike manoeuvres, gravity assist, in-orbit experience to the public. Earth’s Auroras (called northern and duration and recording phases. to put it into the path of the outer solar southern lights as seen in Alaska), Jovian The trajectory: Deciding a direct path for system. Following a helio-centric orbit, Auroras are not caused by solar fl ares. spacecra s to reach their target distances using Earth’s gravity assist, it was The planet’s huge mass, intense magnetic is a highly fuel consuming aff air. If a cra launched towards Jupiter. This entire fi eld and gaseous atmosphere cause their has to be propelled into space directly, exercise however added miles to the path own fl ares. When Jupiter spins on its axis, it consumes as much fuel as it would to be travelled. In all Juno traversed 2.8 it is like a big electromagnet being rotated. consume to launch it from the earth billion kilometres to reach Jupiter. This generates currents which when strike into space. Hence, to reduce this energy The 66-foot diameter by 15-foot the atmosphere, charge the surrounding requirement, astrophysicists use the height spacecra , hexagonally shaped, particles. Being concentrated around its gravitational pull of a nearby planet as a three-winged solar panelled spacecra , poles, the Jovian aurora generates nearly sling shot to put the spacecra into outer employed the stable spinning elliptical 10 million volts! These are occurring regions. This is called a gravity assist orbit. This mode of operation allows continuously. However, Juno will make fl yby. for accurate and stable control of the further intense studies from a much closer Juno too required a gravity assist spacecra . position. Science Reporter, SEPTEMBER 2016 18 COVER STORY

EARLIER MISSIONS EXPLORING JUPITER 1. – 1973: The fi rst spacecraŌ to cross the belt and skim the . It sent visuals of Jupiter’s moons, existence of the radiaƟ on belt and presence of magnetosphere. However, the intense and unexpected radiaƟ on belt that it encountered gave rise to funcƟ onal errors and erroneous readings. 2. – 1974: This was principally launched with as the target; 12 months aŌ er the fi rst craŌ , Pioneer 11 reached Jupiter. This too was a fl yby mission While Pioneer and Voyager, on their and it sent back visuals of the moons, fl uid nature of the interior of the planet, interstellar missions, skimmed the magnetosphere and atmosphere. Both Pioneers paved way for further advancements planet and sent back spectacular in the construcƟ on of spacecraŌ . images, the spacecraft Galileo 3. – 1979: Another fl yby mission sent images of the moons, rings and was exclusively commissioned in magneƟ c fi elds. This was a very short fl yby of 48 hours and hence not many details 1989 to reach Jupiter and study its obtained. However, at a closed distance of 349000 km from the centre, it gave spectacular imagery. moons. 4. – 1979: On its way to Saturn and , Voyager 2 reached the cloud of the panels runs to 66 feet, which fold tops of Jupiter closer than the previous probe. This fl yby mission sent clear images neatly at the time of pre-launch and open of volcanic acƟ vity on Io, tectonic plates of and craters of . These up in such a way that they constantly face visuals helped scienƟ sts to further improve the technology of space craŌ s. the Sun throughout the entire expedition. 5. – 1992: Ulysses, a solar probe, used Jupiter as gravity assist to proceed Overall they have a surface area of 256 further in its journey. During this, it recorded the magnetosphere. The gravity of square feet absorbing the sunrays and Jupiter deviated its path from the calculated value and hence again, Ulysses visited providing a continuous stream of energy the planet, this Ɵ me farther away and made more recordings. Since the probe had to the instruments. no cameras, no images were taken. In addition, the mission duration is so well timed in design that it avoids 6. Galileo orbiter – 1995 to 2003: This was the fi rst spacecraŌ designed as an any eclipses and the instruments draw exclusive mission to Jupiter. As an orbiter probe it orbited Jupiter 34 Ɵ mes in the modest power making use of the available span of seven years. Detail visuals and data were received about the moons. Galileo technology. released a probe into the atmosphere which parachuted down to 150 km, recording 57 minutes of imagery, before disintegraƟ ng. This was a major milestone and set a Leaving no traces: Despite all the benchmark for further missions. measures there will be progressive degradation of the equipment due to 7. Cassini – 2000: Another fl yby mission to Saturn, Cassini sent the best harsh environments encountered on the colour visual images of the planet. At a height of around 26000 km, the smallest planet and Juno has to make quick and recorded picture was of detail 60 km across. timed readings to send back before it is time to end the mission. 8. – 2007: En-route to Pluto, this spacecraŌ stopped by Jupiter for gravity assist. During this period it recorded further details of the moons. Due to Keeping the tradition of deep-space irretrievable memory error of the data handling computer, some recordings were missions, Juno has time only till February lost. However, the system was rebooted in two days and New Horizons conƟ nued to 2018 before which it has to destroy itself stream readings. by deorbiting. This is in order to prevent any contamination from Earth (in the form of hidden bacteria or microbes on Adopting a helio-centric orbit, it fl ew exposed to the orbit once every rotation. the spacecra ) that may unintentionally past the orbit of , cruised inwards In all, at three rotations per minute the be present and carried into space by a again towards the Earth for gravity instruments will make 400 sweeps during defunct spacecra . assist and then entered the outer solar its fl ight from pole to pole. The path is so The world looks forward to Juno’s system. Cruising silently for two years, calculated that Juno does not enter the communication to unravel and demystify the fi nal stage of approach to Jupiter was night cycle of Jupiter. the hidden secrets of our solar system. encountered. This lasted for 178 days. Drawing solar power: Jupiter being The path of its orbit around Jupiter farther away from the Sun receives nearly Ms Susheela Srinivas is an Electronics Engineer by was to enter at the north, drop to a level 25 per cent lesser solar energy than the education and an Entrepreneur by profession. She lower than the inner radiation belt and Earth. However, specially designed solar is a well-published writer with regular contributions exit from the south. This helped Juno panels atop Juno employ advanced solar to Deccan Herald for their supplements. avoid intense radiation regions. cells which are 50 per cent more effi cient Address: #189, I F cross, 3rd Stage, 4th Block, As per the design, the fi eld of and radiation tolerant than the cell Basaveshwaranagar, Bengaluru-560079; Email: view of the instruments on Juno will be hitherto used in earlier missions. The span [email protected] 19 Science Reporter, SEPTEMBER 2016

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