China embarks on a historic mission to land on the far side of the Moon (Source theverge.com)
Early Saturday morning in China, a rocket will launch, carrying a lander and a rover bound for the Moon. It will mark the beginning of China’s ambitious lunar mission known as Chang’e-4, which will attempt to land spacecraft on the Moon’s far side — the region that always faces away from Earth. No other nation has ever attempted such a feat — which means the mission could catapult China into spaceflight history. So far, China is among an elite group of three countries that have landed a spacecraft softly on the surface of the Moon. Apart from America’s notable Apollo missions, the former Soviet Union also landed robotic spacecraft on the lunar surface, with the last mission occurring in 1976. In 2013, China entered the fray, putting a lander and a rover on the Moon. That mission, known as Chang’e-3, was part of a decades-long campaign that China devised to study the Moon with robotic spacecraft. Prior to Chang’e-3, the country had put a spacecraft in lunar orbit and had also crashed a vehicle into the lunar dirt. Now, the next step is to visit a part of the Moon that’s never been fully explored. It’s a significant step because landing on the far side of the Moon is an incredibly challenging task. The Moon is tidally locked with Earth, meaning it rotates around its axis at about the same time it takes to complete one full orbit around our planet. The result: we only see one half of the Moon at all times. This near side of the Moon is the only region that we’ve landed on gently, because there’s a direct line of sight with Earth, enabling easier communication with ground control. To land on the far side of the Moon, you must have multiple spacecraft working in tandem. In addition to the lander itself, you need some kind of probe near the Moon that can relay communications from your lander to Earth.