The Moon Impact Probe developed by the Indian Space Research Organisation,
India's national space agency, was a lunar probe that was released by ISRO's
Chandrayaan-1 lunar remote sensing orbiter which in turn was launched, on
22 October 2008, aboard a modified version of ISRO's Polar Satellite Launch
Vehicle. It discovered the presence of water on the Moon.
The Moon Impact Probe separated from the moon-orbiting Chandrayaan-1 on 14
November 2008, 20:06 and crashed, as planned, into the lunar south pole after
a controlled descent. The MIP struck the Shackleton Crater at 20:31 on 14
November 2008 releasing underground debris that could be analysed by the
orbiter for presence of water/ice. With this mission, India became the fifth
entity to reach the lunar surface. Other entities to have done so are the former
Soviet Union, the United States, the European Space Agency and Japan.
Kalam's vision The probe was a product of former
President Abdul Kalam's vision who felt that since the Chandrayaan orbiter was
already going so near to the moon, the mission would have more scientific
relevance if the probe was included. He believed that the moon could not be left
to a few countries and that India should not be left behind The Times of India
also reported a political motive by former president Abdul Kalam as "He
believed that if this was done, India "could always stake" a claim to a
portion of the Moon." At the same time, The Indian Express reported Kalam as
saying "no nation can claim the moon as its own. The resources of the moon
should be a common property and that is one of the aims of the moon mission."
Mission objectives The main objectives of the MIP were to
demonstrate the technologies for reaching a specified location on the
Moon, qualifying technologies required for any future soft landing missions,
and scientific exploration of the moon from close range just prior to the
impact. The probe was designed to collide with
the lunar surface and eject underground soil which could then be analysed by
instruments on the orbiting Chandrayaan for the presence of water ice, and
organic and other materials. Configuration and payloads
The MIP carried three instruments: Radar Altimeter – which measured the
altitude of the probe during descent and provided information on qualifying
technologies for future landing missions. The operating frequency band
was 4.3 GHz ± 100 MHz. Video Imaging System – acquired close
range images of the surface of the Moon during descent and before impact. The
video imaging system consisted of an analog CCD camera.
Mass Spectrometer based payload CHACE – measured trace constituents of the lunar
atmosphere during descent. This instrument was a quadrupole mass
spectrometer with a mass resolution of 0.5 amu and sensitivities to partial
pressures on the order of 1.3×10−11 pascals.
The probe used aluminium sandwich structure onto which the payloads were
mounted. The probe attached to the mother spacecraft with a ball lock
separation system which jettisoned the unit from the Chandrayaan. A solid
propellent de-orbit mortar nudged the craft into lunar orbit, while spin
thrusters stabilized the orientation enabling imaging system to capture the
descent profile. The probe's external surface had four
oval-shaped anodised aluminium plates measuring 120mm X 180 mm on which the
image of the Indian flag was depicted, complete with the Emblem of India and
the words "Satyameva Jayate". These plates were attached to each one of the
four vertical sides of the probe. As per ISRO specifications these plates had to
endure a temperature range from -50 degrees celsius and as high as +150
degrees celsius. Mission chronology
India launched the Chandrayaan-1 spacecraft using a modified version of
the PSLV C11 on 22 October 2008 from Satish Dhawan Space Centre, Sriharikota,
Andhra Pradesh at 06:22 IST. The lunar probe separated from
Chandrayaaan-1, in a 102 km circular polar orbit around the Moon, at 20:06
IST on 14 November 2008. After separation, it first fired its spin up
rockets and then its retro rocket to lower itself to an orbit intersecting
the lunar surface. While descending, the MIP continuously sent information back
to the Chandrayaan-1 orbiter which in turn beamed the information back to
earth. After a 25-minute controlled descent, it struck the Moon at 20:31
IST, 14 November 2008 at a speed of 1.69 kilometers per second. The crash
destroyed the probe. It crashed into Shackleton Crater, at the lunar south
pole, 89°S 30°W, at 20:31 on 14 November 2008 releasing underground material that
could be analyzed by the orbiter for the presence of water ice.
Discovery of water On 25 September 2009, ISRO announced
that the MIP had discovered water on the moon just before impact. This
announcement was made after the discovery of water was announced on
September 24, 2009 by Science magazine by the NASA payload Moon Mineralogy
Mapper carried on board Chandrayaan-1. MIP discovered water on moon before
NASA's Moon Mineralogy Mapper. The announcement of this discovery was not
made until NASA confirmed it. This gave the answer to the
millennia-old question whether there is water on or in Earth’s moon when it led
to the discovery of water in its vapour phase by the CHACE payload on board the
Moon Impact Probe and complementarily in its solid phase by the Moon Mineralogy
Mapper payload on board the main orbiter in the Chandrayaan I mission. This
‘discovery-class-of-finding’ by CHACE was achieved by direct in situ
measurement of the lunar atmosphere during the descend journey of the MIP to
the Lunar South Pole, while M3 discovered water in ice form by remote
sensing techniques. As water cannot retain its liquid phase in the lunar
environment because of its own vapour pressure and the ultra-high vacuum
prevailing there, it can be found in solid and gaseous phases. While the Moon
Mineralogy Mapper, a payload by NASA, on board Chandrayaan I lunar orbiter has
detected, by mapping almost 97% of the lunar surface using remote sensing
techniques, the presence of water in ice form in higher latitudes especially in
the polar caps, the CHACE payload in the lunar impactor has directly detected
water in its gaseous form along 14 degree E meridian from 45 degree N to 90
degree S latitude, with a latitudinal resolution of around 0.10 and
altitudinal resolution of ~ 250 m from 98 km altitude till impact .
See also Chandrayaan-1
Exploration of the Moon LCROSS
List of current and future lunar missions
Lunar water SELENE
References