Chandrayaan-1, India's first mission to Moon, was launched successfully on
October 22, 2008 from SDSC (need expanding?) SHAR, Sriharikota. The spacecraft
orbited around the Moon at a height of 100 km from the lunar surface and
provided chemical, mineralogical and photo-geologic mapping of the Moon. The
spacecraft carried a total of 11 scientific instruments developed in India and
After completion of the major mission objectives, the orbit was raised to 200 km
in May 2009. The satellite made more than 3400 orbits around the moon in its
life time. The mission was concluded after the communication with the spacecraft
was lost on August 29, 2009.
The payloads onboard Chandrayaan-1 are,
The objective of HySI is to obtain spectroscopic data for mineralogical
mapping of the lunar surface.
The data from this instrument helped in improving the available information
on mineral composition of the surface of Moon.
Also, the study of data in deep crater regions/central peaks, which
represents lower crust or upper mantle material,
may help in understanding the mineralogical composition of Moon’s interior.
The uniqueness of the HySI was in its capability of mapping the lunar
surface in 64 contiguous bands in the VNIR,
the spectral range of 0.4-0.95 µm region with a spectral resolution of
better than 15 nm and spatial resolution of 80 m,
with swath coverage of 20 km.
HySI collected the Sun’s reflected light from the Moon’s surface through a
optics and focus on to an APS area detector for this purpose.
The dispersion was achieved by using a wedge filter so as to reduce
the weight and compactness of the system compared to using a prism /
The wedge filter was an interference filter with varying thickness along one
dimension so that the transmitted spectral
range varies in that direction. The wedge filter was placed in close
proximity to an area detector.
Thus, different pixels in a row of the detector received irradiance from the
same spectral region but different spatial regions in the across track
In the column direction of the detector, different rows received irradiance
of different spectral as well as spatial regions in the along track
direction. The full spectrum of a target was obtained by acquiring image
data in push broom mode, as the satellite moves along the column direction
of the detector. An Active Pixel Sensor (APS) area array detector with
built-in digitizer mapped the spectral bands.
The payload mass was 2.5 kg and its size is 275 mm x 255 mm x 205 mm.HySI
payload is developed by SAC, ISRO
By accurately measuring the roundtrip
travel time of the laser
pulse, highly accurate range/spot elevation measurements can be made.
LLRI consisted of a 10 mJ Nd:YAG laser with 1064 nm wave source operating at 10
Hz pulse repetition
mode. The reflected laser pulse from the lunar surface is collected by a 200 mm
Ritchey-Chrétien Optical receiver and focused on to a Silicon Avalanche
Photodetector. The output of the detector was amplified and threshold detected
for generating range information to an accuracy < 5m.
ihFour constant fraction
discriminators provided the slope information in addition to range
information. The different modes of operation of LLRI and the range
computations from the detector output were controlled and computed by a FPGA
based electronics. The processed outputs of LLRI was used for generating
high accuracy lunar topography. The payload mass was 11.37 kg with base
plate.LLRI payload is developed by LEOS, ISRO.
HEX covers the hard X-ray region from 30 keV to 270 keV.
The experiment is designed primarily to
study the emission of low energy (30-270 keV) natural gamma-rays from the
lunar surface due to 238U and 232Th and
their decay chain nuclides.
The geometric detector area of 144 cm2 was realized by nine Cadmium Zinc
Telluride (CZT) arrays,
each 4 cm x 4 cm (5 mm thick), composed of 256 (16x16) pixels (size: 2.5 mm
x 2.5 mm).
Each CZT array was readout using two closely mounted Application Specific
Integrated Circuits (ASICs),
which provided self-triggering capability.
The detector was biased at the cathode with –550 V and the electronic charge
signals were collected at the anode.
A Cesium Iodide (CsI (Tl)) scintillator crystal coupled to photomultiplier
tubes (PMT), was used as the anticoincidence system (ACS).
A specially designed collimator provided a field of view (FOV) of 33 km X 33
km at the lunar surface from a 100 km orbit.
The spatial resolution of HEX was 33 km and the mass was 14.4 kg.
The impact probe of 35 kg mass was attached at the top deck of the main
released during the final 100 km x 100 km orbit at a predetermined time to
impact at a pre-selected location.
During the descent phase, it was spin-stabilized.
The total flying time from release to impact on Moon was around 25 minutes.
The primary objective was to demonstrate the technologies required for
landing the probe at a
desired location on the Moon and to qualify some of the technologies related
to future soft landing missions.
such as Ca, Ti and Fe on the surface of the Moon.The instrument utilised
technologically innovative Swept Charge Device (SCD) X-ray sensors,
which were mounted behind low profile gold/copper collimators and
aluminium/polycarbonate thin film filters. The system had the virtue of
providing superior X-ray detection, spectroscopic and spatial
measurement capabilities, while also operating at near room temperature.
A deployable proton shield protected the SCDs during passages through
the Earth’s radiation belts, and from major particle events in the lunar
orbit. In order to record the incident solar X-ray flux at the Moon,
which was needed to derive absolute lunar elemental surface abundances,
C1XS also included an X-ray Solar Monitor.
With its wide field-of-view of ± 52 degrees, XSM provides observation of
the solar X-ray spectrum from 1-20 keV with good energy resolution (<
250 keV[at]5[dot]9 keV) and fast spectral sampling at 16 s intervals. The
total mass of C1XS and XSM was 5.2 kg
The C1XS instrument is primarily based on the D-CIXS instrument
on the ESA SMART-1 mission.
Chandrayaan-1 X-ray Spectrometer (C1XS) is realised primarily
through ESA funds with partial support from ISRO.
The hardware has been developed at the Rutherford Appleton
Laboratory, UK in collaboration with the ISRO Satellite Centre,
Bangalore and exhibits significant improvements over the
instrument flown on SMART-1.
SIR-2 was a grating NIR point spectrometer working in the 0.93-2.4 microns
wavelength range with 6 nm spectral resolution. It collected the Sun’s light
reflected by the Moon with the help of a main and a secondary mirror. This light
is fed through an optical fiber to the instrument’s sensor head, where it was
reflected off a dispersion grating. The dispersed light reaches a detector,
which consisting of a row of photosensitive pixels that measured the intensity
as a function of wavelength and produces an electronic signal, which is read out
and processed by the experiment’s electronics.The mass of the instrument was 3.3
kg and the instrument unit dimension is 260 mm x 171 mm x 143 mm.
SIR-2 is developed by the Max-Planck-Institute for Solar System Science, through
the Max-Planck Society, Germany and ESA.
The SARA instrument consisted of neutral atom sensor CENA (Chandrayaan-1
Energetic Neutrals Analyzer), solar wind monitor SWIM and DPU (Data
Processing Unit). CENA and SWIM interface with DPU, which in turn interfaces
with the spacecraft. The masses of CENA, SWIM and DPU
are 2 kg, 0.5 kg and 2 kg respectively, totaling the SARA mass as 4.5
kg.SARA is realised through ESA, in collaboration with Swedish Institute
of Space Physics, Sweden and Space Physics Laboratory,
Vikram Sarabhai Space Centre, ISRO. The Data Processing Unit of this
payload/ experiment is designed and developed by ISRO, while Swedish
Institute of Space Physics develops the payload.
The objective of Mini-SAR was to detect water ice in the permanently
shadowed regions on the Lunar poles, upto a depth of a few meters.An onboard
SAR at suitable incidence would allow viewing of all permanently shadowed
areas on the Moon, regardless of whether sunlight is available or the
angle is not satisfactory. The radar would observe these areas at incidence
angle near 45 degrees, recording echoes in both orthogonal senses of
received polarization, allowing ice to be optimally distinguished from dry
lunar surface.The Mini-SAR radar system operated as an
altimeter/scatterometer, radiometer, and as a synthetic aperture radar
The Mini-SAR system transmitted Right Circular Polarization (RCP) and
received, both Left Circular polarization (LCP) and RCP. In scatterometer
mode, the system measured the RCP and LCP response in the altimetry
footprint, along the nadir ground track. In radiometer mode, the system
measured the surface RF emissivity, allowing determination of the near
normal incidence Fresnel reflectivity. Meter-scale surface roughness and
circular polarization ratio (CPR) wre determined for this footprint. This
allowed the characterization of the radar and physical properties of the
lunar surface (e.g., dielectric constant, porosity) for a network of points.
When directed off nadir, the radar system will image a swath parallel to the
orbital track by delay/Doppler methods (SAR mode) in both RCP and LCP.The
synthetic aperture radar system worked at a frequency 2.38 GHz, with a
resolution of 75 m per pixel from 100 km orbit and its mass was 8.77
kg.Miniature Synthetic Aperture Radar (MiniSAR) is from Applied Physics
Laboratory, Johns Hopkins University and Naval Air Warfare Centre, USA
The primary Science goal of M3 was to characterize and map lunar surface
mineralogy in the context of lunar geologic evolution.
This translates into several sub-topics relating to understanding the
highland crust, basaltic volcanism,
impact craters, and potential volatiles.
The primary exploration goal was to assess and map lunar mineral resources
at high spatial resolution to support planning for future,
targeted missions.The M3 scientific instrument was a high throughput
pushbroom imaging spectrometer, operating in 0.7 to 3.0 µm range.
It measures solar reflected energy, using a two-dimensional HgCdTe detector
The spectral range 0.7 to 2.6 µm captures the absorption bands for the most
important lunar minerals. In addition, the spectral range 2.5 to 3.0 µm is
critical for detection of possible volatiles near the lunar poles. The
presence of small amounts of OH or H2O can be unambiguously identified from
fundamental absorptions that occur near 3000 nm.
M3 measurements are obtained for 640 cross track spatial elements and 261
spectral elements. This translates to 70 m/pixel spatial resolution and 10
nm spectral resolution (continuous) from a nominal 100 km polar orbit for
Chandrayaan-1. The M3 FOV is 40 km in order to allow contiguous
orbit-to-orbit measurements at the equator that will minimize lighting
condition variations.Moon Mineralogy Mapper (M3) payload is from Brown
University and Jet Propulsion Laboratory, USA through NASA
RADOM aimed to qualitatively and quantitatively characterise the radiation environment in near lunar space, in terms of particle flux, dose rate and deposited energy spectrum.The specific objectives are to
Radiation exposure of crew members on future manned space flight had been recognised as an important factor for the planning and designing of such missions. Indeed, the effects of ionising radiation on crew health, performance and life expectancy are a limitation to the duration of man’s sojourn in space. Predicting the effects of radiation on humans during a long-duration space mission requires i) accurate knowledge and modelling of the space radiation environment, ii) calculation of primary and secondary particle transport through shielding materials and through the human body, and iii) assessment of the biological effects of the dose.The general purpose of RADOM is to study the radiation hazards during the Moon exploration. Data obtained will be used for the evaluation of radiation environment and radiation shielding requirements for future manned lunar missions.RADOM was a miniature spectrometer-dosimeter containing one semiconductor detector of 0.3 mm thickness, one charge-sensitive preamplifier and two micro controllers. The detector weighs 139.8 mg. Pulse analysis technique is used for obtaining the deposited energy spectrum, which is further converted to the deposited dose and flux in the silicon detector. The exposure time for one spectrum is fixed at 30 s. The RADOM spectrometer measured the spectrum of the deposited energy from primary and secondary particles in 256 channels.
RADOM mass was 160 g.RADOM is from Bulgarian Academy of Sciences.