Mission Information
MISSION_START_DATE 2008-10-22T12:00:00.000Z
MISSION_STOP_DATE 2009-08-28T12:00:00.000Z
Mission Overview
    Chandrayaan-1, the first Indian mission to Moon, was designed to carry out
    high resolution remote sensing studies of the Moon to further our 
    understanding of its origin and evolution.  At 00:52 UT on 22 October 
    2008, the Indian Space Research Organization (ISRO) launched Chandrayaan-1
    on-board an upgraded Polar Satellite Launch Vehicle (PSLV-C11) from the 
    Satish Dhawan Space Center (SDSC) in Sriharikota located along the 
    southeast coast of India.  The PSLV-C11 injected the orbiter spacecraft 
    into an eleven-hour elliptical transfer orbit around the Earth on 23 
    October 2008.
    The launch was planned such that the Moon is at one of its nodes when the 
    spacecraft arrives.  In order to have multiple launch opportunities every 
    month and to contain burn errors, a phasing loop strategy with multiple 
    loops and five Earth bound maneuvers was adopted.  The injection 
    parameters are as follows:
      Semi-major axis : 17971.73 km
      Eccentricity    : 0.63094
      Inclination     : 17.9112 deg
      Perigee height  : 254.457 km
      Apogee height   : 22932.741 km
    From 25 October through 4 November 2008 several maneuvers were performed 
    to put the spacecraft into a lunar transfer trajectory, and on 8 November 
    Chandrayaan-1 was successfully inserted into a lunar orbit.  By 12 
    November the spacecraft had reached its intended 100-km circular polar 
    orbit for chemical, mineralogical, and photo-geologic mapping of the Moon 
    by its eleven on-board instruments; scientific observations were scheduled
    to continue at this altitude for two years.  The details of the five Earth
    bound maneuvers, lunar insertion maneuver, and circularizing maneuvers at 
    the Moon are provided here:
     |        | Central | Perigee | deltaV |  Dur   | Post Maneuver Orbit   |
     | Burn   |  Body   | Number  |  (m/s) |  (s)   | perigee x apogee (km) |
     | EBN #1 |  Earth  |    4    | 344.43 |   -    |   299.2 x  37908.1    |
     | EBN #2 |  Earth  |    8    | 328.14 | 912.36 |   336.3 x  74715.6    |
     | EBN #3 |  Earth  |    9    | 221.69 | 567.73 |   347.8 x 165015.1    |
     | EBN #4 |  Earth  |   10    |  77.17 | 192.18 |   459.4 x 266612.9    |
     | EBN #5 |  Earth  |   11    |  60.70 | 147.68 |   972.8 x 379859.2    |
     | TCM    |  Earth  |         |   0.82 |   5.59 |   802.8 x 378499.2    |
     | LOI    |  Moon   |    -    | 366.96 | 817.07 |   507.9 x   7510.1    |
     | LBN #1 |  Moon   |    -    |  26.60 |  56.95 |   197.8 x   7507.1    |
     | LBN #2 |  Moon   |    -    | 448.20 | 868.00 |   183.0 x    255.2    |
     | LBN #3 |  Moon   |    -    |  17.03 |  31.30 |   103.3 x    253.9    |
     | LBN #4 |  Moon   |    -    |  32.13 |  58.60 |   101.9 x    102.8    |
    From 16 to 19 May 2009 the Chandrayaan-1 spacecraft was raised to a 200-km
    orbit to keep the temperature of the orbiter down after star trackers 
    failed.  This change enabled further studies of orbital perturbations and 
    gravitational field variations and imaging of the lunar surface with a 
    wider swath. After completing more than 3400 orbits of the Moon in 312 
    days and providing a large volume of data from its suite of sensors that 
    met most mission objectives, communication with the spacecraft was 
    abruptly lost around 20:00 UT on 28 August 2009.  ISRO officially 
    terminated the mission on 31 August 2009.
  Instruments and Experiments
      Terrain Mapping Camera (TMC) is designed to image in the panchromatic 
      spectral band of 0.5 to 0.75 microns with a stereo view in the forward, 
      nadir, and aft directions of the spacecraft movement and a base-to-
      height ratio of 1.  The swath of the instrument is 20 km.  The key 
      features of TMC are:
        Spatial sampling  : 5 x 5 sq.m (from 100-km orbit)
        Swath             : 20 km
        Spectral band     : Panchromatic (0.5 to 0.75 micro-m)
        Stereo mode       : Along track triplet, B/H = 1
        No. of gains & exposure : 4 each
        Square wave response    > 25
        Signal to noise ratio   > 350
      The instrument is from Space Applications Centre, Ahmedabad, India.
      The Hyper Spectral Imager (HySI), operating in the visible and near 
      infrared spectral region, is one of the three imaging instruments on-
      board the Chandrayaan-1 spacecraft for mineralogical study of the Moon. 
      HySI is designed to map the entire lunar surface in 64 contiguous bands 
      in the visible and near infrared (VNIR: 421 to 964 nm) with a spatial 
      sampling of 80 m.  A wedge filter is employed for the spectral 
      separation, and the image is mapped onto an area detector.  The detector
      output is processed in the front-end electronics to generate the 64-band
      with 12-bit quantization. The key features of HySI are:
        Spatial sampling        : 80 x 80 sq.m (from 100-km orbit)
        Swath                   : 20 km
        Spectral range          : 461 to 964 nm
        No: of spectral bands   : 64 continuous
        No: of gains            : 2
        No: of exposure setting : 4
        Quantization            : 12-bits
        Signal to noise ratio   > 100
        Square wave response    > 40
      The instrument is from Space Applications Centre, Ahmedabad, India.
      The Moon Mineralogy Mapper (M3) is an imaging spectrometer that operates
      from the visible into the near-infrared (0.42 to 3.0 micron) where 
      highly diagnostic mineral absorption bands occur.  The instrument 
      parameters and measurement modes for M3 are:
           40-km FOV (allows contiguous orbit overlap)
           405 to 3000 nm spectral range
           12 bits/pixel
        Target mode (full resolution):
           6000 spatial pixels (70 m/pixel)
           260 spectral channels (10 nm/channel)
           1 GB/orbit downlink:  10 to 12 deg longitude swath
        Global Mode (reduced resolution):
           300 spatial pixels (140 m/pixel for 100-km lunar polar orbit)
           86 spectral channels (mixed 20 and 40 nm/channel)
           1 GB/orbit downlink:  135 deg longitude swath (alternating poles)
      The instrument is from Jet Propulsion Laboratory, NASA, USA.
      The Lunar Laser Ranging Instrument (LLRI) is designed to measure the 
      topography of the lunar surface.  A 10-mJ diode-pumped pulsed laser 
      together with a 20-mm diameter telescope and a silicon avalanche 
      photodiode are the principal optical assemblies of this active remote 
      sensing instrument.  The specifications of LLRI are:
        Maximum range          : 100 km (>100 km)
        Range accuracy         <= 5 m (<5 m)
        Range resolution       <= 5 m (<1.5 m coarse, <25 cm fine)
        Data update rate       : 10 Hz
        Transmitter wavelength : 1064 nm
        Pulse energy (min)     : 10 mJ
        Spectral bandwidth     : 0.05 nm
        Spectral Rx bandwidth  < 10 nm
        Optical Rx FOV         : 0.05 deg
      The instrument is from Laboratory for Electro-optics, Bangalore, India.
      The Chandrayaan-1 X-ray Spectrometer (C1XS) is an X-ray imaging 
      spectrometer comprising 24 Swept Charge Device (SCD) detectors and a 
      micro-structure collimator/filter assembly.  The detectors are arranged 
      in three arrays of 8 (2 x 4) detectors each, providing an overall field 
      of view of 32 by 12 degrees in the 0.5 to 10 keV range with a resolution
      of 140 eV.  The SCDs are based upon CCD technology but have 
      significantly lower read noise and can also operate at higher 
      temperatures.  (The C1XS SCDs operate with good signal-to-noise at -10 
      degrees Celsius.)  This is achieved by an electrode and clocking 
      arrangement that 'sweeps' the charge to one collector in a corner of the
      chip.  The instrument is from Rutherford Appleton Laboratory, UK.
      An X-ray Solar Monitor (XSM) supports the C1XS observations, providing 
      solar spectra as calibrations for the lunar data collected by C1XS from 
      which absolute elemental abundances can then be derived.  XSM has a wide
      field of view of 104 degrees and operates in the 0.8 to 20 keV spectral 
      range. Stand-alone observations of long-term solar X-ray emissions can 
      also be made.  The detector comprises silicon diodes cooled by Peltier 
      elements. The instrument is from Rutherford Appleton Laboratory, UK.
      The Sub Infrared Spectrometer (SIR-2) is a miniaturized point-
      spectrometer with a InGaAs array detector designed to provide good 
      signal-to-noise at temperatures around -70 degrees Celsius.  The 
      spectrometer operates in the 0.9- to 2.4-micrometer wavelength range and
      has 256 spectral channels with a resolution per channel of 6 nm/pixel. 
      This is coupled to a lightweight off-axis telescope which has an 
      aperture of 70 mm and a field of view of 1.1 mrad.  A dedicated radiator
      provides passive cooling of the optics and the spectrometer during 
      observations.  The instrument is from Max Planck Institute for Solar 
      system science, Germany.
      High Energy X-ray spectrometer (HEX) is designed to have a spatial 
      resolution of about 33 km at energies below 120 keV.  The low signal 
      strength of these emissions requires a large area detector with high 
      sensitivity and energy resolution, thus a new generation CdZnTe solid 
      state detector is used in this experiment.  The specifications of HEX 
        Energy range        : 30 to 270 keV
        Energy resolution   : 12% at 60 keV
        ACS threshold       ~ 50 keV
        Spatial threshold   : 33 km x 33 km FOV
      The instrument is from ISRO satellite centre, Bangalore, and Physical
      Research Laboratory, Ahmedabad, India.
        Instrument    : SARA (Sub-keV Atom Reflecting Analyzer)
        Type          : Mass spectrometer and solar wind monitor
        Measurements  : 10 ev - 2 kev with a 100-m spatial resolution
        Science Goals : Atmospheric neutrals (H-Fe) composition and magnetic
        Principal Investigator : S. Barabash, ESA
      The Sub-keV Atom Reflecting Analyser (SARA) comprises two detectors. 
      The Chandrayaan Energetic Neutrals Analyser (CENA) is a low-energy 
      neutral atom sensor with an range from 10 eV to 3.3 keV, and the Solar 
      Wind Monitor (SWIM) is an ion mass spectrometer with an energy range 
      from 10 eV to 15 eV.  The main characteristics of the two sensors are:
        Parameter              CENA                   SWIM
        Particle to measure    Neutrals               Ions
        Energy range           10 eV to 3.2 keV       10 eV to 15k eV
        Energy resolution      50%                    7%
        Mass range             1 to 56 amu            1 to 40 amu
        Mass resolution        H,O, Na/Mg/Si/Al,      H,  He, O (> 20 amu)
                               K/Ca, Fe
        Full FOV               15 x 160 deg           9 x 180 deg
        Angular resolution     9 x 25 deg             4.5 x 22.5 deg
        G-factor/sector, w/o   10^-2 cm2^2 sr eV/eV   1.6x10^-4 cm^2 sr eV/eV
        Efficiency             0.2 cm^2 se eV/eV(at 25eV)
        Efficiency (%)         0.01 to 1              0.1 to 5
      The instrument is from Swedish Institute of Space Physics, Sweden, and
      Space Physics Laboratory, VSSC, Trivandrum, India.
      The Miniaturized Synthetic Aperture Radar (Mini-SAR) is a single 
      frequency (S-band; 13-cm wavelength) synthetic aperture radar in a light
      weight (9 kg) package.  Mini-SAR utilizes a unique hybrid polarization 
      architecture which allows determination of the Stokes parameters of the 
      reflected signal, intended to distinguish volume scattering (caused by 
      presence of ice) from other scattering mechanisms.  The parameters for 
      Mini-SAR are:
        Frequency            : 2.38 GHz
        Spacecraft velocity  : 1631 m/s
        Range swath          : 8 km
        Strip length         : 325 km (SAR), 300 km (Scatterometer)
        Boresight fain       : 26.1 dB
        Antenna efficiency   : 53%
        Transmit pulse width : 84 micro-sec (SAR), 83 micro-sec 
        PRF                  : 3100 Hz (SAR), 3750 Hz (Scatterometer)
        A/D sampling frequency : 8
      The instrument is from Applied Physics Laboratory, Johns Hopkins
      University, USA.
      The Moon Impact Probe (MIP) has two technological and one scientific 
      experiments:  a Moon Imaging System (MIS), a radar altimeter, and a mass
      spectrometer known as CHACE (Chandra's Altitudinal Composition 
      Explorer). The nearly 34-kg MIP with features of a mini spacecraft is 
      designed to be piggy-backed on main orbiter and released for descent to 
      the Moon at a pre-determined location.  The MIS essentially comprises a 
      CCD camera and processing electronics and is designed to acquire images 
      of lunar surface, compress them, and then transmit the compressed data 
      through a telemetry link to the orbiting Chandrayaan-1 spacecraft.  A 
      altimeter consists of a C-band radar that makes use of an FM-CW type 
      transmitter with central and modulation frequencies of 4.3 GHz and 100 
      Hz, respectively, and a transmitted output power of 1 W (CW) with a 
      frequency deviation of +/-50 MHz.  The salient features of CHACE are:
        Mass range     : 1 to 100 amu
        Detector type  : Electron multiplier
        Resolution     : Unit resolution
        Dynamic range  : 10^10
        Min. detectable partial pressure: 5 x 10^-14 torr
        Scan rate      : 15 spectra/minute
        Sensitivity    : 10^-1 A/torr
      The instrument is from Vikram Sarabhai Space Centre, Trivandrum, India.
      The Radiation Dose Monitor (RADOM) is designed to measure the spectrum 
      (in 256 channels) of the energy deposited by primary and secondary 
      cosmic particles.  It is a miniature spectrometer dosimeter containing a
      single 0.3-mm thick semiconductor detector with a 2-cm-square area, one 
      low noise hybrid charge-sensitive preamplifier (A225F type) from AMPTEX 
      Inc., a fast 12-channel analog-to-digital converter, two micro-
      controllers, and buffer memory.  A pulse analysis technique is used for 
      obtaining the spectrum of the energy deposited in the silicon detector 
      which is then analysed and further converted to deposited dose and flux 
      values.  The instrument is from Solar-Terrestrial Influences Laboratory,
      Bulgarian Academy of Sciences.
  Mission Phases
    Two main phases of significant periods of spacecraft activity are defined
    for the Chandrayaan-1 mission:  The Launch and Early Orbit phase and the
    Lunar Orbit phase.
      Mission Phase Start Date:  2008-10-22
      Mission Phase Stop Date:   2008-11-08
        The Launch and Early Orbit Phase extended from the launch of the 
        spacecraft from the SDSC in Sriharikota, India, at 00:51 UT on 22 
        October 2008.  This phase starts from lift-off and ends with lunar 
        capture.  Orbit raising maneuvers and transmitting X-band data through
        the stowed DGA are the major activities during this phase.  During 
        other major activities, the spacecraft was kept at single inertial 
        attitude due to power, thermal, and communication link constraints. 
        The RADOM instrument was turned on during the first transfer orbit and
        was kept on continuously.  Three images were taken by TMC during en 
        route:  the Australian sector of Earth at 02:38 UT on 29 October 2008,
        the crescent Earth at 07:29 UT on 29 October 2008, after burn #4, and 
        the crescent Moon at 08:25 UT on 4 November 2008, after burn #5.
      Mission Phase Start Date:  2008-11-08
      Mission Phase Stop Date:   2009-08-28
      The sphere of influence occurred around 18:05:30 on 7 November 2008. 
      The Lunar Orbit Insertion maneuver was carried out at 11:20:46 on 8 
      November 2008 to put the spacecraft into an elliptical orbit (500 x 7500
      km) around Moon.  The orbit was later circularized to 100 x 100 km after
      four lunar burns.
      All the payloads were commissioned in a phased manner.  The 
      dates of each payload were:
        |              |   Commissioning    |
        |   Payload    |     Date (UTC)     |
        |  TMC, RADOM  |  Operated en route |
        |  LLRI        |  2008-11-16T03:50  |
        |  HySI        |  2008-11-16T07:40  |
        |  Mini-SAR    |  2008-11-17T14:00  |
        |  M3          |  2008-11-18T22:15  |
        |  SIR-2       |  2008-11-19T08:23  |
        |  C1XS        |  2008-11-20T17:42  |
        |  HEX         |  2008-12-05T11:52  |
        |  SARA        |  2008-12-09T11:50  |
        |              |  2009-01-29T04:00  |
    Summary of Sub-Phases during Lunar Orbit
      Name:  Limited operation zone (noon-midnight zone-1)
      START_DATE:  2008-11-16
      STOP_DATE:   2009-01-30
      Sun angle with respect to the orbital plane:  -30 deg to 45 deg.
      Scientific Focus:  Optical Imaging
      Instruments operated:  TMC, HySI, M3, SIR-2, C1XS, LLRI, RADOM
      DESCRIPTION:  To contain the bulk temperature of the spacecraft, the 
      payload operations were restricted during this phase.  The maximum 
      number of payload sessions in a day was four.  Typical data were 
      collected of the surface of the Moon such as polar, equatorial (near 
      side, far side), and higher latitude regions (near side, far side) by 
      TMC, HySI, M3, SIR-2, C1XS, and LLRI.  A campaign to image Apollo 
      landing sites by all the imaging payloads was carried out from 7 to 11 
      January 2009.  A 180-deg yaw rotation of the spacecraft was carried out 
      on 18 December 2008.
      Name:  Intense imaging operation zone-1
      START_DATE:  2009-01-31
      STOP_DATE:   2009-02-14
      Sun angle with respect to the orbital plane:  Greater than 45 deg and
      less than 60 deg.
      Scientific Focus:  Optical Imaging
      Instruments operated:  TMC, HySI, M3, SIR-2, C1XS, LLRI, RADOM, SARA
      DESCRIPTION:  During this period, all the optical imaging payloads were 
      operated every orbit.  The coverage of TMC-HySI was around the 
      equatorial region (+30 to -30 degrees), and M3 was operated in global 
      mode.  SIR-2 and C1XS were operated during the illuminated limb of the 
      orbit, including the terminator crossing, while LLRI was operated during
      the non-illuminated limb of the orbit.
      Name:  Dawn-dusk zone-1
      START_DATE:  2009-02-15
      STOP_DATE:   2009-04-15
      Sun angle with respect to the orbital plane:  Greater than 60 deg.
      Scientific Focus:  Radar imaging
      Instruments operated:  Mini-SAR, HEX, C1XS, RADOM, SARA
      DESCRIPTION:  During this period, Mini-SAR was operated at both poles. 
      As the spacecraft bulk temperature was low, the power requirement for 
      the heater increased.  HEX was operated during the poles for a period of
      20 minutes.  The spacecraft was re-oriented about 40 to 50 degrees about
      the yaw axis to maximize power generation and to charge the battery 
      during the payload non-operation period.  The solar array was flipped by
      180 degrees on 25 March 2009 when the Sun angle was 60 degrees with 
      respect to the solar panel.
      Name:  Intense imaging operation zone-2
      START_DATE:  2009-04-15
      STOP_DATE:   2009-05-18
      Sun angle with respect to the orbital plane:  Greater than 45 deg and
      less than 60 deg.
      Scientific Focus:  Optical imaging
      Instruments operated:  TMC, HySI, M3, SIR-2, C1XS, RADOM, SARA
      DESCRIPTION:  During this period, the regions that M3 did not image 
      during the previous imaging season were covered in global mode.  Higher 
      latitudes of the southern hemisphere (-30 to -60 degrees) were imaged by
      TMC-HySI. SIR-2 and C1XS were operated during the illuminated limb of 
      the orbit. However, after failure of a star sensor, all payload 
      operations were minimized.
      Name:  200-km operation zone-1 (noon-midnight zone-2)
      START_DATE:  2009-05-19
      STOP_DATE:   2009-08-16
      Sun angle with respect to the orbital plane:  Less than 60 deg.
      Scientific Focus:  Optical imaging
      Instruments operated:  TMC, HySI, M3, SIR-2, C1XS, RADOM, SARA
      DESCRIPTION:  The altitude of the orbit was raised to 200 km during the 
      period from 16 to 19 May 2009.  During this maneuver, all the 
      illumination-dependent instruments were operated.  Systematic coverage 
      was performed by TMC-HySI starting with the polar zone, mid-latitude 
      regions, and global coverage was carried out by M3 under different 
      illumination conditions.  A 180-degree yaw rotation was carried out on 
      18 June 2009. Periodic attitude acquisition maneuvers were carried out. 
      During the total solar eclipse on 22 July 2009, nine consecutive images 
      of Earth were acquired by TMC to cover the path of totality.  Other 
      payloads such as M3, SWIM (SARA), C1XS were also switched on during the 
      Name:  200-km operation zone-2 (Dawn-dusk zone-2)
      START_DATE:  2009-08-17
      STOP_DATE:   2009-08-28
      Sun angle with respect to the orbital plane:  Greater than 60 deg.
      Scientific Focus:  Radar imaging
      Instruments operated:  Mini-SAR, C1XS, RADOM
      DESCRIPTION:  Due to the change in the altitude of the orbit, the Mini-
      SAR operation sequences were modified and polar imaging in SAR mode was 
      started on 17 August 2009.  Periodic attitude acquisition maneuvers were
      carried out.  On 20 August 2008, bi-static observation with the Lunar 
      Reconnaissance Orbiter (LRO) was attempted.  However, it was not 
      successful because of the uncertainty in the attitude.  The RADR imaging
      continued until radio contact with the spacecraft was lost on 28 August 
Mission Objectives Overview
    The main scientific objective of lunar mission was the photo-selenological
    and chemical mapping of the Moon.  Studies with high spectral and spatial 
    resolutions are needed to improve our understanding of the origin and 
    evolution of the Moon.  The Chandrayaan-1 mission aimed to achieve this 
    goal by carrying out remote sensing observations over a wide range of the 
    electromagnetic spectrum for simultaneous mineralogical, chemical, and 
    photo-geological mapping of the lunar surface at resolutions better than 
    previous and contemporary lunar missions.
    The Chandrayaan-1 payload had the following broad science and technology
      Science objectives: 
      - Perform systematic topographic mapping of the entire lunar surface, 
        including the far side and polar regions. 
      - Prepare a three-dimensional atlas of the Moon with high spatial and 
        altitude sampling for scientific studies.  High-resolution imagery of 
        the entire Moon will help detailed study of specific lunar regions of 
        scientific interest and further our understanding of lunar evolution.
      Science objectives:
      * Map the entire lunar surface in 64 contiguous band in the visible and
        near-infrared from 421 to 964 nm with a spatial separation of 80 m.
      * Combine these data with the study of deep craters such as the South 
        Pole-Aitken basin which contains surface expression of lower crustal 
        or upper mantle material, as well as central hills of targeted lunar 
        craters, to further our understanding of the mineralogical composition
        of Moon's crust and its formation and evolution.
      Science objectives:
      - Acquire low-resolution spectroscopic data of the entire lunar surface
        at 14 m/pixel in 86 spectral channels to be used as a base-map.
      - Acquire high spectral resolution data at 80 m/pixel in 260 channels.
      - Perform a detailed mineral assessment of the different lunar terrains
        to improve our understanding of the geologic evolution of the lunar 
        crust and lay a foundation for future in-depth exploration of the 
      Science Objectives:
      - Obtain high spatial and spectral resolution data to study mineralogy 
        of selected lunar targets (e.g., the distribution of olivine on the 
        central peaks of craters).
      - The data will contribute to investigations of:
        - The origin of the Moon and the Earth-Moon system,
        - The character and evolution of the primitive lunar crust,
        - The thermal evolution of the Moon and lunar volcanism, and
        - The impact record and redistribution of crustal materials.
      Science Objectives:
      - Acquire altimetry data that will accurately map topology of the Moon.
      - Generate an improved model of the lunar gravitational field for better
        understanding of the geophysics of the Moon.
      - Use the data for significant insight into lunar evolution.
      Science objectives:
      - Perform global mapping of the Moon in X-rays of key rock-forming
        elements (Si, Mg, Al and Fe).
      - Determine the abundance of Mg across the Moon.
      - Perform geochemical and stratigraphic investigations of large craters,
        basins, and mare deposits, in particular the South Pole-Aitken basin.
      - Evaluate of key lunar resources.
      - Study the interaction of lunar plasma with the solar wind.
      - Investigate Earth's X-Ray aurora and magnetotail.
      - Study targets of opportunity such as comets during cruise.
      - Study the long-term evolution of solar flares with XSM.
      Science objectives:
      - Study the transport of volatiles on the lunar surface through the
        detection of 46.5 keV line from 210Pb decay which is a product
        of volatile 222Rn, both belonging to the 238U decay series.
      - Perform spectral studies at hard X-ray energies (30 to 270 keV)
        using solid state detectors with good energy resolution.
      Science objectives:
      - Map the elemental composition of the lunar surface including the
        permanently shadowed areas.
      - Directly image the magnetic anomalies of the lunar surface (in 
        sputtered and backscattered LENAs).
      - Study the processes of space weathering.
      - Study the sputtering sources of the exospheric gases.
      Science objectives:
      - Map a previously unknown region of the Moon and collect information
        relevant to the possible existence of water/ice.
      - Collect information about the scattering properties of the permanently
        dark areas near the lunar poles at optimum viewing geometry and map 
        the terrain of these areas which are invisible to normal imaging 
      Science objectives:
      - Land in the south polar region of the Moon, an area of prime
        interest from both lunar science and lunar resource perspectives.
      - Demonstrate technologies useful for future landing mission and perform
        a novel scientific experiment to measure the tenuous composition of 
        the lunar day side.
      - Perform detailed remote sensing studies of the Moon at various
        wavelengths across the electromagnetic spectrum.
      Scientific objectives:
      - Monitor the radiation environment en route and during lunar orbit.
      - Measure the amount of radiation absorbed due to energetic particles
        of galactic and solar origins.
      - Monitor the effect of solar particle events to assess the dose 
        received by the spacecraft and estimate the same for future, long-
        duration  missions to the Moon.
  Ground Segment Overview
    The Chandrayaan-1 ground segment can be subdivided into four main 
    entities: the Mission Operations Complex (MOX), Ground Stations Network 
    (GSN), Indian Space Science Data Centre (ISSDC), and Payload Operations 
    Centre (POC).
    Mission Operations Complex
      The MOX was located at Peenya campus of ISTRAC in Bangalore, India.  All
      phases of mission operations for Chandrayaan-1 were executed from the 
      MOX, and it provided facilities such as the Main Control Room, the 
      Mission Analysis Room, Mission Planning and Flight Dynamics, the Mission
      Scheduling and Payload Scheduling Facility.  Mission and spacecraft 
      specialists along with the operations crew from ISTRAC carried out 
      operations from the MOX.
    Ground Stations Network
      The Telemetry, Tracking and Command (TTC) functions, which are nearly 
      continuous health monitoring as well as commanding and tracking data 
      collection, were performed by a comprehensive network of ground 
      stations. For the orbit raising phase, the TTC functions were executed 
      by ground stations at ISTRAC network (Bangalore, Mauritius, Port Blair, 
      Brunei, Biak, Trivandrum), USN (Hawaii), INPE (Alcantara, Cuiaba), JPL 
      DSN (Goldstone, Canberra, and Madrid), and APL (Maryland).  After the 
      100,000-km cross-over, IDSN (Bangalore-D18, D32), JPL DSN (Goldstone, 
      Canberra, and Madrid), and APL were used both for TTC functions and for 
      science data collection.
    Indian Space Science Data Centre
      The Indian Space Science Data Centre (ISSDC) is the infrastructure which
      facilitated science data processing, archival, and dissemination 
      functions for scientists.  The data transfer system at ISSDC, with 
      suitable security systems, provided for the distribution of science data
      (as per the data policy) to the concerned institutions.  Level-0 and 
      Level-1 data products from the instruments, as applicable, were 
      routinely produced at ISSDC.  The computer networking at ISSDC catered 
      to connectivity to the IDSN operations facility, the MOX, and the POCs.
    Payload Operations Centres
      Within India, the POCs were the Space Applications Centre (SAC) in 
      Ahmedabad (TMC, HySI, MIS), the ISRO Satellite Centre (ISAC) in 
      Bangalore (C1XS, HEX, LLRI), and the Vikram Sarabhai Space Center (VSSC)
      in Trivandrum (SARA, MIP).  The POCs were responsible for the analysis 
      of science data, providing quality information at the ISSDC and the MOX,
      generation of higher level products, advising the Satellite Control 
      Centre (SCC) on any operations requirements and command needs, providing
      calibration support and updates when necessary, and providing adequate 
      support for the life cycle maintenance of the software provided to the 
  Acronym List
    AOCE      Attitude and Orbit Control Electronics
    AOCS      Attitude and Orbit Control System
    APL       Applied Physics Laboratory
    BDH       Baseband Data Handling
    BMU       Bus Management Unit
    BPSK      Binary Phase Shift Keying
    CASS      Coarse Analog Sun Sensor
    CCD       Charge Coupled Device
    CCSDS     Consultative committee for Space Data Systems
    CENA      Chandrayaan-1 Energetic Neutral Analyzer
    CIXS      Chandrayaan-1 Imaging X-ray Spectrometer
    DGA       Dual Gimbal Antenna
    DTG       Dynamically Tuned Gyroscope
    DSN       Deep Space Network
    EBN       Earth Bound maneuver Number
    GSN       Ground Station Network
    H/W       Hardware
    HEX       High Energy X-ray Spectrometer
    HySI      Hyper Spectral Imager
    IAC       Inertial Attitude Control
    IDSN      Indian Deep Space Network
    INPE      National Institute for Space Research in Brazil
    ISAC      ISRO Satellite Centre
    ISRO      Indian Space Research Organization
    ISSDC     Indian Space Science Data Centre
    ISTRAC    ISRO Telemetry, Tracking network
    I/F       Interface
    JPL       Jet Propulsion Laboratory
    LBN       Lunar Bound maneuver Number
    LLRI      Lunar Laser Ranging Instrument
    LOI       Lunar Orbit Insertion
    LRO       Lunar Reconnaissance Orbiter
    LTT       Lunar Transfer Trajectory
    M3        Moon Mineralogy Mapper
    MIP       Moon Impact Probe
    MLI       Multi Layer Insulation
    MOX       Mission Operations Complex
    Mini-SAR  Miniaturized Synthetic Aperture Radar
    RADOM     Radiation Dose Monitor
    POC       Payload Operation Centre
    PM        Phase Modulation
    PSK       Phase Shift Key
    PSLV      Polar Satellite Launch Vehicle
    TCM       Trajectory Correction Maneuver
    TMC       Terrain Mapping Camera
    SAC       Space Applications Centre
    SADA      Solar Array Drive Assembly
    SARA      Sub-keV Atom Reflecting Analyzer
    SCC       Satellite Control Centre
    SDSC      Satish Dhawan Space Center
    SIR-2     Short wave Infrared Radiometer
    SPSS      Solar Panel Sun Sensor
    SSR       Solid State Recorder
    SWIM      Solar Wind Monitor
    TTC       Telemetry, Tracking and Command
    USN       Universal Space Network, Inc.
    VSSC      Vikram Sarabhai Space Center
    XSM       Solar X-ray Monitor