My Dark Sky

Just late last October, India launched the Chandrayaan-1 spacecraft to the Moon. After two weeks cruising in space, the spacecraft finally entered into the lunar orbit on November 8.

When we say we launch a spacecraft to an object, say the Moon, in a layperson’s mind the spacecraft will go from Point A (the Earth) straight to Point B (the Moon). No, we don’t do that because it’ll be very fuel consuming if we were going to launch that way (although it’s the fastest way to get there). Instead we use what we called transfer orbits to transfer the spacecraft from Earth’s orbit to the Moon’s orbit. In this way, we can save some fuel but it’ll take longer time to reach our destination.

In the past two weeks since its launch, Chandrayaan-1 has successfully increased its orbital height five times from its initial apogee (farthest point from Earth) of 22,860 km to the Lunar Transfer Tracjectory with an apogee of 380,000 km.

Then on November 8, Chandrayaan-1 entered the lunar orbit. As the probe passed about 500 km from the Moon, its liquid engine was fired to reduce its velocity to a point that the lunar gravity was able to capture it into orbit around the Moon.

In the coming days, the height of Chandrayaan-1’s orbit will be gradually reduced to achieve a final polar obit of 100 km from the lunar surface. After that, the Moon Impact Probe (MIP) will be released and, as its name suggested, impact the Moon to kick up some dust for the onboard instruments to analyse.

Congratulations India!

Here’s an animiation showing the whole mission.

~ by thChieh on November 10, 2008.

Posted in Moon
Tags: Chandrayaan-1