The launch of Chandrayaan-1 took place at 6:22 am Indian Standard Time (00:52 UT) on October 22, 2008 from the Second Launch Pad at Satish Dhawan Space Centre, SHAR, Sriharikota in the Nellore district of Andhra Pradesh state. Sriharikota is situated at a distance of about 80 km to the North of Chennai. Chandrayaan-1 spacecraft began its journey from Earth onboard India's Polar Satellite Launch Vehicle (PSLV-C11) and first reached a highly elliptical Initial Orbit (IO). In the Initial Orbit, the perigee (nearest point to Earth) was about 255 km and apogee (farthest point from the Earth) is about 22,860 km. After circling the Earth in its Initial Orbit for a while, Chandrayaan-1 spacecraft was taken to five more elliptical orbits whose apogees were progressively higher a 37,900 km, 74,715 km, 164,600 km, 267,000 km and 380,000 km respectively. This was done by firing the spacecraft's Liquid Apogee Motor (LAM) at opportune moments when the spacecraft was near perigee. During this phase of the mission, the Terrain Mapping Camera (TMC), which is one of the eleven payloads of Chandrayaan-1 carried by spacecraft, was successfully switched ON and it took the pictures of the Earth and Moon. Additionally, Radiation Dose Monitor (RADOM), another payload of Chandrayaan-1, was also switched ON. As it approached the apogee of its final Earth Bound Orbit at 380,000 km, the spacecraft passed at a distance of about 500 km from the Moon on November 8, 2008 since Moon had arrived there in its journey round the Earth. At that time, the spacecraft's LAM was again fired. This slowed down the spacecraft sufficiently to enable the gravity of the moon to capture it into an elliptical orbit whose periselene (nearest point to the moon's surface) was at 504 km and whose aposelene (farthest point to the moon's surface) was at 7,502 km. Following this, the height of the spacecraft's orbit around the moon was reduced in four steps. As a result of this, the periselene was reduced from 504 km to 200 km, and then to 182 km and finally to 100 km while the aposelene was reduced from 7,502 km to 255 km and then to 183 km and finally to 100 km. Thus, Chandrayaan-1 spacecraft reached its intended operational lunar polar orbit of about 100 km height from the moon's surface on November 12, 2008. After this, TMC sent excellent images of the lunar surface. On November 14, 2008, the Moon Impact Probe (MIP), carrying the painting of Indian tricolor on its sides, was separated from the spacecraft and after a 25 minute journey, impacted the lunar surface near the South polar region of the moon at around |
region of the moon
