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India's Chandrayaan-1 Successfully Reaches its Operational Lunar Orbit
Today, Chandrayaan-1 spacecraft has successfully reached its intended operational orbit at a height of about 100 km from the lunar surface. This followed a series of three orbit reduction manoeuvres conducted during the past three days by repeatedly firing the spacecrafts 440 Newton Liquid Engine. As part of these manoeuvres, the engine was fired for a cumulative duration of about sixteen minutes. As a result of these manoeuvres, the farthest point of Chandrayaan-1s orbit (aposelene) from the moons surface was first reduced from 7,502 km to 255 km and finally to 100 km while the nearest point (periselene) was reduced from 200 km to 182 km and finally to 100 km. With this, the carefully planned complex sequence of operations to carry Chandrayaan-1 from its initial Earth orbit to its intended operational lunar orbit with the use of its liquid engine has been successfully completed. During these operations, Chandrayaan-1s liquid engine built by Liquid Propulsion Systems Centre (LPSC), Thiruvananthapuram, has been fired a total of ten times successfully. In its present operational orbit, Chandrayaan-1 spacecraft takes about two hours to go round the moon once. From this operational circular orbit of about 100 km height passing over the polar regions of the moon, it is intended to conduct chemical, mineralogical and photo geological mapping of the moon with Chandrayaan-1s 11 scientific instruments (payloads). Two of those 11 payloads Terrain Mapping Camera (TMC) and Radiation Dose Monitor (RADOM) have already been successfully switched ON. TMC has successfully taken the pictures of Earth and moon. The next major event of Chandrayaan-1 mission planned in the coming days is the release of Moon Impact Probe (MIP) from the spacecraft and its eventual hitting of the moons surface. It may be recalled that after its successful launch by PSLV-C11 on October 22 into an initial Earth orbit, Chandrayaan-1 spacecraft proceeded towards moon and successfully entered into an elliptical orbit around that celestial body on November 8, 2008. Since its launch, the spacecrafts health and orbit have been continuously monitored from the Spacecraft Control Centre of ISRO Telemetry, Tracking and Command Network (ISTRAC) with critical support from antennas of Indian Deep Space Network (IDSN) at Byalalu. Posted by: john frum 2008-11-12 |
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