Chandrayaan-2

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ABSTRACT:

"THE MOON" with the history of the early solar system etched on it beckons mankind from time immemorial to admire its marvels and discover its secrets. Understanding the moon provides a pathway to unravel the early evolution of the solar system and that of the planet earth.
Through the ages, the Moon, our closest celestial body has aroused curiosity in our mind much more than any other objects in the sky. This led to scientific study of the Moon, driven by human desire and quest for knowledge.
Exploration of the moon got a boost with the advent of the space age and the decades of sixties and seventies saw a myriad of successful unmanned and manned missions to moon. This was followed by a hiatus of about one and a half-decade. During this period we refined our knowledge about the origin and evolution of the moon and its place as a link to understand the early history of the Solar System and of the earth.
With regards to moon exploration, it was felt that an Indian mission would only reinvent the wheel as the U.S.A. had been there before. If schedules hold, spacecraft from India should be moon-bound by 2008. After launch, Chandrayaan will go around the earth twice before being fired towards the moon. The entire journey of 386,000 km will take 5.5 days. The scientific community in India is very enthusiastic about this mission.
ISRO Officials say that one reason for backing the lunar mission is that talented young scientists who join the organization require more challenging tasks. Besides, such cutting-edge scientific missions can generate a number of spin-off technologies that can be applied in other areas. The possibility of exploiting precious resources on the lunar surface cannot be discounted. New discoveries have sparked off a moon rush, and India does not wish to be left behind. There are purely scientific reasons as well - one of the objectives of the Chandrayaan project will be to produce a gravity map of the moon.
The possibility of finding water (in the form of ice) in the Polar Regions has been the trigger for the current rush in lunar exploration. The presence of water could help in colonizing the moon as it would result in substantial cost savings when permanent human residence is planned.


Mission Objectives:
To realise the mission goal of harnessing the science payloads, lunar craft and the launch vehicle with suitable ground support systems including Deep Space Network (DSN) station.
To realise the integration and testing, launching and achieving lunar polar orbit of about 100 km, in-orbit operation of experiments, communication/ telecommand, telemetry data reception, quick look data and archival for scientific utilisation by scientists.
Scientific Objectives:
The Chandrayaan mission is aimed at high-resolution remote sensing of the moon in visible, near infrared (NIR), low energy X-rays and high-energy X-ray regions. Specifically the objectives are
• To prepare a three-dimensional atlas (with high spatial and altitude resolution of 5-10 m) of both near and far side of the moon.
• To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium as well as high atomic number elements such as Radon, Uranium & Thorium with high spatial resolution.
• The Simultaneous photo geological, mineralogical and chemical mapping through Chandrayaan mission will enable identification of different geological units to infer the early evolutionary history of the Moon. The chemical mapping will enable to determine the stratigraphy and nature of the Moon's crust and thereby test certain aspects of magma ocean hypothesis. This may allow to determine the compositions of impactors that bombarded the Moon during its early evolution which is also relevant to the formation of the Earth.
• Radiation environment of the Moon produced by solar radiation and solar and galactic cosmic rays: The reflectance spectrum is useful for mineral identification, the fluorescent X-ray spectrum and solar and galactic cosmic-ray produced gamma radiation for chemical mapping, and radiogenic gamma and alpha particle spectrum for mapping of radioactive nuclides (U, Th, K, etc.) and in understanding the leakage of radon from the lunar interior and its transport on the lunar surface.

Chandrayaan-1:

Chandraayan-1

The first ISRO Moon probe, Chandrayaan 1, was an important step away from ISRO’s previous focus on practical space technology applications, such as remote sensing, communications, distance learning, telemedicine, and security. These efforts were all aimed at supporting India’s national development goals. For many years the feeling was that everything they did had to have a direct payoff for the people and particularly for the impoverished masses. The mission was the first pure space science mission the Indian agency had even done.
The Insat series of communications satellites and the unique weather sensors that they carry are a good example of ISRO’s traditional approach. These satellites were at first launched mostly by Europe’s Ariane and are now being put into orbit by India’s own Geosynchronous Space Launch Vehicle (GSLV). The technology for the spacecraft themselves was almost entirely homegrown. ISRO’s policy was to use as little foreign input as possible, both in order to develop their own industrial base and—so they claimed—to hold down costs.
Chandrayaan 1 represented a major break from that tradition. It incorporated instrument packages from Britain, Germany, Russia, Sweden, and the US, as well as from India itself. This represented a major step forward in India-US cooperation. Overcoming the bureaucratic and political obstacles that have long stood in the way of such bilateral programs was a major achievement for all involved.



Searching for Helium-3
The mission would look for, amongst others, Helium-3-one of the fuels for nuclear fusion. A utilizable supply of Helium-3 can finally bring about the answer to the Energy crisis that is iminent upon us. The mission thus has economical as well as humanitarian values.


Kalam’s Thumbs-up
Dr.Abdul Kalam, former president has come out and said that the mission will be of immense economical value to India and thus silencing critics who ask whether such a mission is required in a country still reeling under poverty.
ISRO officials have time and again said that Chandrayaan is not a “me too” effort. “Despite many manned and unmanned missions undertaken in the last four-and-a-half decades, not everything about the moon is fully understood,” says Nair. “One of the main objectives of Chandrayaan-I would be to fill the gaps in our knowledge of the moon. Besides, it will also help increase the sophistication of our space systems like INSAT and IRS.”




Description:
Spacecraft for lunar mission is :
Cuboid in shape of approximately 1.5 m side.
Weighing 1380 kg at launch and 675 kg at lunar orbit.
Accommodates eleven science payloads.
3-axis stabilized spacecraft using two star sensors, gyros and four reaction wheels.
The power generation would be through a canted single-sided solar array to provide required power during all phases of the mission. This deployable solar array consisting of a single panel generates 750W of peak power. Solar array along with yoke would be stowed on the south deck of the spacecraft in the launch phase. During eclipse, spacecraft will be powered by Lithium ion (Li-Ion) batteries.
After deployment, the solar panel plane is canted by 30º to the spacecraft pitch axis.
The spacecraft employs a X-band, 0.7m diameter parabolic antenna for payload data transmission. The antenna employs a dual gimbal mechanism to track the earth station when the spacecraft is in lunar orbit.
The spacecraft uses a bipropellant integrated propulsion system to reach lunar orbit as well as orbit and attitude maintenance while orbiting the Moon.
The propulsion system carries required propellant for a mission life of 2 years, with adequate margin.
The Telemetry, Tracking & Command (TTC) communication is in S-band frequency.
The scientific payload data transmission is in X-band frequency.
The spacecraft has three Solid State Recorders (SSRs) Onboard to record data from various payloads.
SSR-1 will store science payload data and has capability of storing 32Gb data.
SSR-2 will store science payload data along with spacecraft attitude information (gyro and star sensor), satellite house keeping and other auxiliary data. The storing capacity of SSR-2 is 8Gb.M3 (Moon Mineralogy Mapper) payload has an independent SSR with 10Gb capacity.

Mission Sequence:
Chandrayaan-1 spacecraft was launched from the Satish Dhawan Space Centre, SHAR, Sriharikota by PSLV-XL (PSLV-C11) on 22 October 2008 at 06:22 hrs IST in an highly elliptical initial orbit (IO) with perigee (nearest point to the Earth) of 255 km and an apogee (farthest point from the Earth) of 22,860 km, inclined at an angle of 17.9 deg to the equator. In this initial orbit, Chandrayaan orbited the Earth once in about six and a half hours.
Subsequently, the spacecraft's Liquid Apogee Motor (LAM) firing was done on 23 October at 09:00 hrs IST, when the spacecraft was near perigee, to raise the apogee to 37,900 km while the perigee to 305 km. The spacecraft took eleven hours to go round the Earth once.
The orbit was further raised to 336 km x 74,715 km on 25 October at 05:48 hrs IST. In this orbit, spacecraft took about twenty-five and a half hours to orbit the Earth once.
The LAM was fired again on 26 October at 07:08 hrs IST to take the Chandrayaan-1 spacecraft to extremely high elliptical orbit with apogee 164,600 km and perigee at 348 km. Chandrayaan-1 took about 73 hours to go round the Earth once.
On 29 October, orbit raising was carried out at 07:38 hrs IST to raise the apogee to 267,000 km and perigee to 465 km. Chandrayaan’s present orbit extends more than half the way to moon and takes about six days to orbit the Earth.
On 4 November at 04:56 hrs IST, Chandrayaan entered the Lunar Transfer Trajectory with an apogee of 380,000 km.
On 8 November at 16:51 hrs IST, the spacecraft’s Liquid engine was fired to reduce its velocity to insert the spacecraft in the lunar orbit (LOI) and enable lunar gravity to capture it. As a result, the spacecraft was in an elliptical orbit with periselene (nearest point to the moon) of 504 km and aposelene (farthest point from the moon) of 7,502 km.
The first orbit reduction manoeuvre was carried out successfully on 9 November at 20:03 hrs IST. Thus the spacecraft was in lunar orbit with 200 km periselene. The aposelene remains unchanged (i.e 7,502 km).
After careful and detailed observation, a series of three orbit reduction manoeuvres were successfully carried out and the spacecraft’s orbit was reduced to its intended operational 100 km circular polar orbit on November 12.
On 14 November at 20:06 hrs IST, the Moon Impact Probe (MIP) was ejected from the Chandrayaan-1 spacecraft and hard landed on the lunar surface near the South Polar Region at 20:31 hrs IST after 25 minutes journey. It placed the Indian tricolor, which was pasted on the sides of MIP on the Moon.


Chandrayaan-2:
After the great success of Chandrayaan-1, the Indian government has given the go-ahead to Chandrayaan-2.
Chandrayaan-1’s project director has said that ISRO has started research for Chandrayaan-2, for which the Indian government has sanctioned the required funds. If all goes well, Chandrayaan-2 is expected to be in orbit by 2012.
ISRO has said the Chandrayaan-II will be a fully indigenous one. Earlier, ISRO had said that Chandryaan-2 is likely to be a joint project between India and Russia, and would accommodate payloads from international space agencies.
The Chandrayaan-2 will feature a rover and a lander. The Chandrayaan-2 mission will aim to land a rover on the Moon. The rover will move on wheels on the Moon’s surface, and pick up rock and soil samples.
Chandrayaan-2’s rover will also be expected to perform on-site chemical analysis and send the data to Chandrayaan-2 in the orbit. Chandrayaan-2 will then transmit the data to Earth.
The estimated cost of the Chandrayaan-1 project is Rs 386 crore, much less than the amount spent by its Japanese and Chinese counterparts. The cost of the Chandrayaan-2 is likely to be higher than that of Chandrayaan-1.
Chandrayaan-2 is the second unmanned lunar exploration mission proposed by the Indian Space Research Organisation (ISRO) and has a projected cost of Rs. 425 crore (US$ 90 million). The mission, proposed to be launched in 2013 by a GSLV launch vehicle, includes a lunar orbiter as well as two rovers: one Lander/rover built by Russia, and a second -smaller- rover built by India. The wheeled rovers will move on the lunar surface, to pick up soil or rock samples for on site chemical analysis. The data will be sent to Earth through the Chandrayaan-2 orbiter. The team headed by Dr.Mylswamy Annadurai who was behind the success of the Chandrayaan-1 mission, is working on Chandrayaan-2.
On November 12, 2007, representatives of the Russian Federal Space Agency (Roskosmos) and ISRO signed an agreement for the two agencies to work together on the Chandrayaan-2 project.ISRO will have the prime responsibility for the orbiter and Roskosmos will be responsible for the lander/rover. The design of the craft was completed in August 2009, with scientists of both countries conducting a joint review. Chandrayaan-2 will be launched on India’s Geosynchronous Satellite Launch Vehicle (GSLV) on 2013.

What is Chandrayaan-2?
The Indian Space Research Organisation (ISRO) is planning 2nd moon mission Chandrayaan-2 in 2013. Russia's Federal Space Agency (Roskosmos) is joining with ISRO for development of Chandrayaan-2 Lander/Rover.
Chandrayaan-2 will consist of the spacecraft and a landing platform with the moon rover. The rover would move on wheels on the lunar surface, pick up samples of soil or rocks, do a chemical analysis and send the data to the spacecraft orbiting above.
The rover will weigh between 30 kg and 100 kg, depending on whether it is to do a semi-hard landing or soft landing. The rover will have an operating life-span of a month. It will run predominantly on solar power.
Chandrayaan 2 Robot:
Chandrayaan-2 will have a unique robot developed indigenously by student-engineers and their professors at the Indian Institute of Technology (IIT) at Kanpur.
The 'SmartNav' robot being developed for the Indian Space Research Organization (ISRO) will help space scientists to navigate moon's surface during the manned moon mission and provide real-time data and pictures of the surface there. The two-legged robot, fitted with sophisticated sensors and high-resolution cameras, is capable of recording information and images using laser beams.

Chandrayaan-2 When?
Chandrayaan-2 planned to be launched by 2013 using spacecraft and launch vehicle of ISRO. The mission is expected to have an operational life of about 2 years.
The Indian Space Research Organisation (ISRO) and Russia's Federal Space Agency (Roskosmos) have signed an Agreement on joint lunar research and exploration. This cooperation envisages Chandrayaan-2, a joint lunar mission involving a lunar orbiting spacecraft and a Lander/Rover on the Moon's surface. ISRO will have the prime responsibility for the Orbiter and Roskosmos will be responsible for the Lander/Rover. A few scientific instruments from other space agencies may also be accommodated on these systems.Chandrayaan-2 will be launched on India's Geosynchronous Satellite Launch Vehicle (GSLV) around 2013 time frame. This agreement is a major milestone in the long-standing cooperation between India and Russia in the area of outer space.

Chandrayaan-2 How?
Chandrayaan-2 will consist of the spacecraft and a landing platform with the moon rover. The platform with the rover will detach itself off after the spacecraft reaches its orbit above the moon, and land on lunar.
A motorised rover will be released on the moon's surface from the lander. The location for the lander will be identified using data from Chandrayaan-1 pyaload MIP .
In Chandrayaan-1, MIP will detach itself from the spacecraft and it will impact on the moon's surface. The MIP will have three instruments. Annadurai, its mass spectrometer will sense the moon's atmospheric constituents as it keeps falling for 18 minutes and crashes on the moon. Its altimeter will measure the instantaneous altitude during its descent. Its video-imaging system will look at the moon from close proximity in order that ISRO scientists may take decisions on the terrain where it will land.
The rover will weigh between 30 kg and 100 kg, depending on whether it is to do a semi-hard landing or soft landing. The rover will have an operating life-span of a month. It will run predominantly on solar power.
If ISRO wants to operate the rover for two or three months, its engineers will configure the vehicle and its instruments including a battery back-up to go into a low-power mode, with the rover waking up when sunlight streams through. When the sunlight comes, the solar-powered battery cells will be re-charged and the equipment will be switched on one by one for the rover to function for another two weeks.The batteries will be re-charged every two weeks.

Design of Chandrayaan-2
The smaller rover and the orbiter of Chandrayaan-2 will be designed and developed by India (ISRO), while Russia will design and construct a soft-Lander and a rover. The platform with the rover will detach from the orbiter after the spacecraft reaches its orbit above the Moon, and land on lunar soil, then the rover will roll out of the platform. The Indian Space Research Organisation (ISRO) is carrying out feasibility studies which will look at powering the Chandrayaan-2 orbiter with nuclear energy. Additional scientific payloads would be acquired from international scientific community.
India has completed the design of Chandrayaan-2, its next mission to the moon - this time in collaboration with Russia - that would have a lander and rover which can collect samples of the lunar soil and analyse them and send back the data.
According to the Bangalore-headquartered space agency, the Chandrayaan-2 mission would have an orbital flight vehicle constituting an Orbital Craft (OC) and a Lunar Craft (LC) that would carry a soft landing system up to Lunar Transfer Trajectory (LTT).

Rovers:
The Russian designed, rover weighs 50 kg, will have six wheels and will be running on solar power. It will land near one of the poles and will operate for a year, roving up to 150 km at a maximum speed of 360 m/h. The Russian rover, which is significantly more advanced and versatile, will carry out all the major explorations.
The Indian rover is smaller, weighing 15 kg will be deployed together with the Russian rover and will separately undertake chemical analysis and the search for availability of materials[clarification needed] on the surface of the Moon. The design is totally indigenous and a significant part of the of it -including the crucial communication links- is being fabricated in Kerala.[7] One aim is to gain experience in robotic payloads, and also to achieve the capability of remotely controlling a system to execute various commands communicated from the Bangalore station.

Nair about Chandrayaan-2:
Nair said ISRO has learnt plenty of lessons from Chandrayaan-1 mission, particularly on the thermal and redundancy management fronts and would seek to improve systems in Chandrayaan-2, slated towards the end of 2013."I think we have got very valuable inputs on the heat radiation from the moon's surface and so on. Accordingly, the thermal design of the future aircraft can be addressed," he said. "Radiation is much beyond our expectations, so we will have to see how the radiation hardening has to be strengthened."
"Then, in redundancy management also, there are some inputs which are available from this (Chandrayaan-1), which we will try to incorporate in Chandrayaan-2."
The ISRO Chairman said contingency operations undertaken by the organisation following the failure of Chandrayaan-1 spacecraft's onboard star sensor earlier last year have worked well and "this is (now) as precise as it was earlier."
"We are able to locate the cameras at specific locations," he said noting some of the stereo images that have come recently. "The fact that we were able to point the spacecraft towards the Earth and capture the (recent) solar eclipse, shows the accuracy of the system."

Nair said 95 per cent of the scientific objectives of Chandrayaan-1 mission have been achieved. "Another five per cent, what's left out, we will try to take up in the next season which is starting in October so that we can complete all the observations."
Nair said India's ground station at Byalalu on the city outskirts has given precision as good as the NASA station.
"We are comparing both the tracking results."
On how the US and Europe, which have flown instruments on board Chandrayaan-1, have taken to the failure of star sensor, Nair said, "They have got more than sufficient data with them and are extremely happy. Now, Indian and foreign scientists are working together to analyse the data and they have promised some results before the year end."

“Three-dimensional pictures of the moon would be available soon”, he said.

Manned Missions?
Sources from ISRO say that after Chandrayaan-2, ISRO is planning a manned mission to the low earth orbit. The space program could pave the way for a manned mission to the moon in 2020. ISRO is also working on an unmanned flight to Mars.

Conclusion:
Along with their recently announced independent manned space exploration program the Chandrayaan series of science missions show that India is determined to be a space power in the full sense of the term. This flows naturally from India’s emergence as a global economic and political power. Over many decades hundreds of thousands of high-quality scientists and engineers have been trained in Indian universities. These men and women have helped propel India to its new status, and giving them challenging and fascinating new space projects is a way for the Indian government to keep this talent at home and busy.
It will be interesting to see how ISRO uses the Russian technology that they are getting for Chandrayaan 2. We should also keep an eye on the laser imaging system that is being developed for the rover. Integrating these systems into the mission is not going to be easy, but if India pulls it off it will be an even more impressive achievement than Chandrayaan 1.