Indian spacecraft enters lunar orbit, makes history (Second lead)November 8th, 2008 - 9:49 pm ICT by IANS
Bangalore, Nov 8 (IANS) India Saturday made history by firing its first unmanned spacecraft Chandrayaan-1 into the lunar orbit, breaking away from the earth’s gravitational field for a rendezvous with the moon.”The complex lunar orbit insertion manoeuvre was conducted perfectly. We have created space history by doing it for the first time. It shows our planning was precise and all calculations were on dot,” a beaming Indian Space Research Organisation (ISRO) chairman G. Madhavan Nair told reporters here after the successful operation.
With this successful manoeuvre, India becomes the fifth country to send a spacecraft to the moon after the US, former Soviet Union, Japan and China. The European Space Agency (ESA), a consortium of 17 nations, also sent a spacecraft to the moon.
Chandrayaan was put into an elliptical lunar orbit when its liquid engine onboard was fired at 4.51 p.m. IST for about 817 seconds (13.6 minutes) from the space agency’s telemetry, tracking and command network (Istrac) on the outskirts of Bangalore.
“The liquid engine was fired when the spacecraft was cruising at about 500 km from the moon to reduce its velocity and enable lunar gravity to capture it into an orbit around the moon,” ISRO said in a statement later.
The Indian Deep Space Network (IDSN) at Byalalu, about 40 km from this tech hub of India, supported the crucial task of transmitting commands and monitoring the vital event with two dish antennas of 18 metre and 32 metre in diameter.
“All operations to insert the spacecraft into the lunar orbit have been completed. The ground stations have also proved that all systems are working normal. It will take five days to stabilise the operations and the moon impact probe (MIP) onboard Chandrayaan will be released to hit the lunar surface Nov 15, when the Indian tri-colour will also be lowered,” Nair said.
The spacecraft is spinning in an elliptical orbit, passing over the polar regions of the moon. The nearest orbit (periselene) is 504 km from the moon’s surface, while the farthest (aposelene) is at 7,502 km. It takes 11 hours to go around the moon once in this orbit.
“The performance of all the systems onboard is normal. Over the next two-three days, the height of the spacecraft’s orbit will be reduced in steps to achieve a final polar orbit of about 100 km height from the moon’s surface,” the statement noted.
The terrain mapping camera (TMC) onboard will continue to take pictures of the moon from the spacecraft. The remaining nine instruments onboard will be switched on by the month-end in tune with the normal phase of the moon.
The TMC was operated twice to take pictures first of the earth and then moon.
In the past 18 days, the liquid engine motor onboard was fired five times at opportune moments to increase the apogee height, first to 37,900 km, then to 74,715 km, 164,600 km, 267,000 km and finally 380,000 km.
Chandrayaan carries 11 scientific instruments, including six foreign payloads — two from the US, three from the European Space Agency (ESA) and one from Bulgaria. The remaining five are indigenously designed and developed by various centres of the state-run ISRO.
The spacecraft was blasted off Oct 22 onboard the 316-tonne polar satellite launch vehicle (PSLV-C11) from the Satish Dhawan space centre at Sriharikota spaceport, about 80 km north of the Tamil Nadu capital Chennai.