GROUND SEGMENT FOR CHANDRAYAAN-1 MISSION

GROUND SEGMENT FOR CHANDRAYAAN-1 MISSION The Ground Segment for Chandrayaan-1 comprises of three major elements : the Ground Station Network including the Indian Deep Space Network (IDSN), Mission Operations Complex (MOX)and Indian Space Science Data Centre (ISSDC). This trio of ground facility ensures the success of the mission by providing to and fro conduit of communication, securing good health of the spacecraft, maintaining the orbit and attitude to the requirements of the mission and conducting payload operations. The ground segment is also responsible for making the science data available for the Payload Scientists along with auxiliary information, in addition to archiving of payload and spacecraft data. Payload Operation Centres (POCs) also form a part of the Ground Segment. Elements of Ground Segment

ABOUT PSLV-Polar Satellite Launch Vehicle

Polar Satellite Launch Vehicle The Indian Space Research Organisation (ISRO) built its first Polar Satellite Launch Vehicle (PSLV) in the early 90s. The 45 m tall PSLV with a lift-off mass of 295 tonne, had its maiden success on October 15, 1994, when it launched India's IRS-P2 remote sensing satellite into a Polar Sun Synchronous Orbit (SSO) of 820 km altitude. Since its first successful launch in 1994, PSLV has launched nine Indian Remote Sensing satellites as well as two micro satellites HAMSAT and IMS-1 built by ISRO, a recoverable space capsule SRE-1, and fourteen small satellites for foreign customers into polar Sun Synchronous Orbits. Besides, it has launched one Indian meteorological satellite Kalpana-1 into Geosynchronous Transfer Orbit (GTO). PSLV has emerged as ISRO's workhorse launch vehicle and proved its reliability and versatility by scoring continuous successes in launching multiple payloads to both SSO as well as GTO. Considering the maturity of Polar Satellite Launch Vehicle (PSLV) demonstrated through various performances, PSLV is chosen for the first lunar mission. The upgraded version of PSLV viz., PSLV-XL (PSLV-C11) will be used to inject the 1380 kg mass spacecraft into a 255 x 22860 km orbit. PSLV has four stages, using solid and liquid propulsion systems alternately. Six strap-on motors augment the first stage thrust. PSLV-XL is the upgraded version of PSLV. In PSLV-XL, the six strap-on motors carry 4 tonne more propellant compared to PSLV; There is also an increase in the length of each strap-on.

PAYLOAD INFORMATION OF CHANDRAYAAN 1

Scientific Payloads

Chandrayaan-1 is an Indian Mission to the Moon. The indigenously developed payload/ experiments are:

TMC Terrain Mapping stereo Camera (TMC) in the panchromatic band, having 5 m spatial resolution and 20 km swath Read More.. HySI Hyper Spectral Imaging camera (HySI) operating in 400-950 nm bands with a spectral resolution better than 15 nm and spatial resolution of 80 m with a swath of 20 km Read More.. LLRI Lunar Laser Ranging Instrument (LLRI) with height resolution of less than 5 m Read More.. HEX High Energy X-ray spectrometer (HEX) using Cadmium-Zinc-Telluride (CdZnTe) detector in the 30-270 keV energy region with spatial resolution of 33 km Read More.. MIP Moon Impact Probe (MIP) as piggyback on the main orbiter of the Chandrayaan-1 spacecraft, which will impact on the surface of the moon. Read More..

Apart from the above indigenous payloads/experiments, ISRO solicited proposals through an Announcement of Opportunity (AO) from International and Indian Scientific Community for participating in the mission by providing suitable scientific payloads, complementing the overall Chandrayaan-1 scientific objectives. Out of the proposals received, six experiments were selected for inclusion in Chandrayaan-1 mission; two of the AO payloads, C1XS and SARA are developed by ESA jointly with ISRO.

The AO payloads Onboard Chandrayaan-1 are:

C1XS Chandrayaan-1 X-ray Spectrometer (C1XS) through ESA - a collaboration between Rutherford Appleton Laboratory,UK and ISRO Satellite Centre, ISRO. Part of this payload is redesigned by ISRO to suit Chandrayaan-1 scientific objectives. Read More.. SIR-2 Near Infra Red spectrometer (SIR-2) from Max Plank Institute for Solar System Science, through Max-Planck Society, Germany and ESA Read More.. SARA Sub keV Atom Reflecting Analyser (SARA) through ESA, from Swedish Institute of Space Physics, Sweden and Space Physics Laboratory, Vikram Sarabhai Space Centre, ISRO. The digital processing unit of this payload/ experiment is designed and developed by ISRO, while Swedish Institute of Space Physics develops the payload. Read More.. RADOM Radiation Dose Monitor Experiment (RADOM) from Bulgarian Academy of Sciences. Read More.. Mini-SAR Miniature Synthetic Aperture Radar (Mini-SAR) from Applied Physics Laboratory, Johns Hopkins University and Naval Air Warfare Centre, USA through NASA Read More.. M3 Moon Mineralogy Mapper (M3) from Brown University and Jet Propulsion Laboratory, USA through NASA Read More..

Summary of Chandrayaan-1 Prime Science Objectives and Wavelength range coverage

Prime Objectives Payload Search for water-ice MiniSAR, HEX, SARA Chemical Mapping C1XS, HEX Mineralogical Mapping HySI, SIR-2, M3 Topography Mapping LLRI,TMC Radiation Environment RADOM, HEX, C1XS Magnetic Field Mapping SARA Volatile Transport HEX Lunar Atmospheric constituent MIP

CHANDRAYAAN 1 SPACE CRAFT DESCRIPTION

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.

CHANDRAYAAN 1 MISSION PROFILE

Mission Sequence

Chandrayaan-1 spacecraft would be launched from the Satish Dhawan Space Centre, SHAR, Sriharikota by PSLV-XL (PSLV-C11) in an highly elliptical initial orbit (IO) with perigee (nearest point to the Earth) of about 257 km and an apogee (farthest point from the Earth) of about 22,858 km. After a few revolutions in the initial orbit, the spacecraft's Liquid Apogee Motor (LAM) firing would be done, when the spacecraft is near perigee, to raise the apogees to 37,421 km and 73,925 km respectively. Subsequently, the LAM is fired to take the Chandrayaan-1 spacecraft to extremely high elliptical orbit with apogees 199,277 km and 269,201 km. Later the spacecraft would be raised to an orbit with 1,019 km perigee and 386,194 km apogee. Once the Chandrayaan-1 spacecraft reaches the vicinity of the Moon, the spacecraft is slowed down sufficiently so as to enable the gravity of the moon capture it into an elliptical orbit (LC). After a careful and detailed observation the height of the spacecraft's orbit will be finally lowered to its intended 100 km circular polar orbit. Following this, the Moon Impact Probe (MIP) would be ejected from Chandrayaan-1 to impact on the lunar surface. Afterwards, all the scientific instruments/payloads are commissioned sequentially and Chandrayaan-1 spacecraft explores the Moon with its array of instruments for two years.

CHANDRAYAAN 1 -SCIENTIFIC OBJECTIVES AND MISSION OBJECTIVES

Scientific Objectives

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

To prepare a three-dimensional atlas (with high spatial and altitude resolution of 5-10 m) of both near and far side of the moon. To conduct chemical and mineralogical mapping of the entire lunar surface for distribution of mineral and chemical elements such as Magnesium, Aluminum, Silicon, Calcium, Iron and Titanium as well as high atomic number elements such as Radon, Uranium & Thorium with high spatial resolution.

The Simultaneous photo geological, mineralogical and chemical mapping through Chandrayaan-1 mission will enable identification of different geological units to infer the early evolutionary history of the Moon. The chemical mapping will enable to determine the stratigraphy and nature of the Moon's crust and thereby test certain aspects of magma ocean 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.

Click here to enlarge

Radiation Environment of the Moon

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. The uranium decay chain, which produces 222Rn and its daughters, forming a thin 'paint' on the lunar surface, are shown on the right. The temperature regimes on the sunlit and night side of the Moon and the permanently shadowed cold Polar Regions are shown schematically. (Ref: Current Science, Bhandari 2004)

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.

CHANDRAYAAN PAY LOD PHOTO GALLERY-

HySI

LLRI

HEX

MIP

C1XS

SIR-2

CHANDRAYAAN PHOTO GALLERY-PAY LOADS-TMC

INDIAN MOON TRIP LAUNCHING SITE BEFORE LAUNCHING

The fully assembled PSLV-C11, which will launch Chandrayaan-1 on October 22, stands encased in the Vehicle Assembly Building of the second launch pad at Sriharikota on Saturday. In the foreground is the launch pad to which the PSLV -C11 will be wheeled on rail tracks on October 18.

SRIHARIKOTA: If all goes well, Chandrayaan-1 spacecraft, to be launched by the Polar Satellite Vehicle (PSLV-C11) on October 22 at 6.20 a.m. from the Sriharikota space port, will reach the lunar orbit on November 8, according to M.Y.S. Prasad, Associate Director, Satish Dhawan Space Centre, Sriharikota.

About 1,000 engineers and technicians of the Indian Space Research Organisation (ISRO) have rolled up their sleeves and are working hard for the past two months to ensure a flawless launch. The 52-hour countdown will begin on October 20 at 4 a.m.

On Saturday, the PSLV-C11, which is 44.4 metres tall and weighs 316 tonnes, looked majestic in the huge Vehicle Assembly Building (VAB) of the state-of-the-art second launch pad on the Sriharikota island. As it gleamed in white and brown colours, the VAB’s massive doors, in contrast, shone in speckled grey.

“All checks on the vehicle are completed. The vehicle is now ready to receive the satellite,” declared T. Subba Reddy, Manager, Second Launch Pad, when journalists visited the complex.

A few kilometres away, Chandrayaan-1 spacecraft, which weighs 1,380 kg, is undergoing a battery of tests to test its flight-worthiness.

The spacecraft will be moved to the VAB on October 14 and married up with the PSLV-11. The “marriage ceremonies” such as filling Chandrayaan-1 with propellants and gas, and cobbling of the heat-shield which protects the spacecraft through searing heat when the rocket climbs through the atmosphere, will be performed over the next four days. On October 18 will begin the extremely slow journey of the rocket with the spacecraft, as if it were a temple chariot with the deity, from the VAB to the launch pad.

The PSLV, which stands on a mobile platform, will be wheeled on rail tracks to the launch pad, also called the umbilical tower, which is one km away. A powerful hydraulic bogey system will slowly pull the vehicle. The one-km journey will take two hours!

“The movement of the vehicle to the launch pad will take place on October 18. There will be minimum four days of work on the launch pad. The launch will take place on October 22 at 6.20 a.m., provided the weather supports us,” said M.C. Dathan, Director, Satish Dhawan Space Centre, Sriharikota.

However, V. Krishnamurthy, the Range Safety Officer for the mission, is a confident man. “Rains do not matter. The launch vehicle is rain-proof. It can get drenched and we can still launch,” he asserted.

The PSLV had lifted off earlier when it was pouring over the island. Only a cyclone would pose a problem to the launch on time. Since this was the time when the north-east monsoon set in, Mr. Krishnamurthy said ISRO had formed a team of weather specialists who would be in Sriharikota six days before the launch.

Depending on their inputs, ISRO would take a decision on when to ignite the rocket.

Mission-life

Chandrayaan-1 will carry 730 kg of propellants. About 600 kg of these propellants will be used to put the spacecraft into lunar orbit at an altitude of 100 km. The spacecraft will have a mission-life of two years and use up 70 kg of propellants during this period, Mr. Prasad said.

Chandrayaan-1 has 11 scientific payloads — five from India and six from abroad. The payloads from abroad includes those from NASA, the European Space Agency and Bulgaria. The payloads will map the chemicals and minerals on the moon, and also prepare a 3-diemensional map of the entire lunar surface. The mission will also give clues on the early origin of the moon.

Mr. Prasad said, “We will be able to confirm whether there is water on the surface of the moon near the Poles with the help of the Chandrayaan mission.” Water on the moon was first identified by a NASA mission called Clementine. Based on that, NASA concluded that there could be a possibility of water in the moon’s South Pole, he added.

Moon Impact Probe

S. Satish, Director, Publications and Public Relations, ISRO, said an important Indian payload on the Chandrayaan-1 was the Moon Impact Probe (MIP). When the spacecraft reached the lunar orbit at an altitude of 100 km, the MIP would eject from Chandrayaan. As the MIP sped towards the moon’s surface, its video-camera would take pictures of the lunar surface. Its altimeter would measure the instantaneous altitude from the moon. A third instrument, a mass spectrometer, would sniff the tenuous atmosphere above the moon.

V. Seshagiri Rao, Deputy Director, Range Operations, Sriharikota, said each payload on the Chandrayaan, was subjected to different tests at Sriharikota. Experts sat in front of consoles and watched the differences in parameters when the payloads were tested. The tests related to solar panel deployment as well.