India was Tuesday set to launch its historic unmanned flight to the moon, the sixth to do so after the US, former Soviet Union, European Space Agency, China and Japan. The skies cleared Tuesday evening after a heavy downpur, cheering scientists counting down to the early Wednesday morning launch.
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As the fully-loaded 44-metre-tall 316-tonne rocket, the Polar Satellite Launch Vehicle (PSLV C11) stood at the second launch pad of the Satish Dhawan Space Centre (SDSC) in Sriharikota, off the Andhra Pradesh coast, 80 km north of Chennai, a meteorogical officer at the spot told agencies: “Though rain is likely at the launch, there is no cyclone threat forecast”.
As the PSLV holds aloft the 1,380-kg lunar orbiter Chandrayaan, waiting for the ignition command at 6.20 a.m. Wednesday, the top brass of the Indian Space Research Organisation (ISRO) decided that “two or three hours before liftoff, met experts will analyse the weather data once again to ascertain possibility of lightning striking the rocket or the spacecraft”, the official added.
Still very much within the earth’s atmosphere, the spacecraft was sitting protected by the rocket’s 3.2-metre bulbous heat shield Tuesday evening as the weather office in Chennai also told us that the chances of a cyclone affecting the launch were slim.
“The low pressure trough is in southern Tamil Nadu, south of Pudukotai,” the Chennai weather bureau said. “It is unlikely to move north in time to affect the Chandrayaan launch.”
A confident S. Satish, director, Publications & Press Relations of the Indian Space Research Organisation (ISRO), told agencies: “Eighteen minutes into the flight the rocket will sling the spacecraft into the 255-km perigee (nearest point to earth) and 23,000 km apogee (farthest point from earth) path to script a new history in the annals of India’s space odyssey,”
From there the spacecraft will be taken into more elliptical orbits, firing its onboard motor - technically called Liquid Apogee Motor (LAM) - towards the moon, 387,000 km from the earth.
Once the spacecraft nears the moon, the LAM will be fired in reverse to slow it down to enable the moon’s gravity to capture Chandrayaan into an elliptical orbit around the lunar poles.
Thereafter the spacecraft’s orbit will be gradually lowered till it is 100 km above the moon’s surface. That is expected to happen around Nov 8.
On Nov 14 the spacecraft will eject an important piece of luggage on to the moon’s surface - the Moon Impact Probe (MIP).
The spacecraft cameras and other instruments that would do the intended tests for the next two years will be activated after that.
The 11 experimental instruments carried by the spacecraft are from different sources - five Indian, two from the US, three from the European Space Agency and one from Bulgaria - and each has a different purpose.
“Designing the spacecraft that would fit these pre-built instruments was a challenge which was overcome with Indian ingenuity,” Mylswamy Annadurai, project director, Chandrayaan, told IANS.
Indian space scientists may not face such problems in Chandrayaan-2 as they can stipulate the payload specifications.
The Indian government has sanctioned Rs.4.25 billion for the second moon mission that is expected to happen sometime in 2011.
That mission will have the Russian Federal Space Agency as a partner which will provide the moon rover.
Looking forward India may plan missions to Mars, Venus, Mercury and also an asteroid or comet flyby mission.