China is on the verge of creating space history after it launched its Chang’e-4 rover on a never-before-attempted mission to the far side of the Moon – the side that we never get to see from Earth.
Although the far side is also referred to as the dark side, you should know that it’s a kind of a misnomer, as it receives as much sunlight as the near side does.
Launched atop a Long March 3B rocket, which blasted off from the Xichang Satellite Launch Center (XSLC) in the wee hours of Saturday morning (1:23 p.m. EST Friday), the lunar lander is well on its way for an early January rendezvous with the so-called dark side of Earth’s Moon.
Chang'e-4, the world's first lunar probe that is expected to make a soft landing on the far side of the Moon, was successfully launched on early Saturday from the Xichang satellite launch center in Southwest China's Sichuan Province. #ChangE4 (Photo: Xie Qiyong) pic.twitter.com/bWT9e7erkI
— Global Times (@globaltimesnews) December 7, 2018
While humans have glimpsed, and even mapped, this untrodden lunar ground in the past – thanks to NASA’s Apollo 8 mission half a century ago and the Soviet Luna 3 mission a decade prior to that – no spacecraft has ever touched down on that side of our planet’s only known natural satellite.
Well, if all goes according to plan, Chang’e-4 is going to change all of that when it makes a soft landing on the Von Kármán crater, sometime between January 1 and 3.
In the past decade. or so, China has been making rapid advances in space technology and is the only country in the world to have soft-landed a space vehicle on the Moon since the then Soviet Union’s Luna 24 mission to retrieve samples of lunar soil in 1976.
China achieved the feat in December 2013, landing its Chang’e-3 rover on Mare Imbrium – a vast lava plain within the Imbrium Basin on the near side of the Moon, becoming only the third country after Russia and the United States to have achieved a lunar touchdown.
Encouraged by Chang’e-3’s success, China stepped up its lunar program for an even bigger mission – the one it set in motion with the Friday launch of Chang’e-3’s repurposed successor, Chang’e-4.
Comprising of a lander and a small rover, Chang’e-4 was, in fact, a backup spacecraft manufactured with the Chang’e-3.
It was as recently as 2015 when China announced that the spare space vehicle was going to be used to achieve something so complex that it has never been attempted before.
The nearly four-metric-ton Chang’e-4 is carrying with it eight scientific instruments, four each on the lander and the rover.
The lander is equipped with the Landing Camera (LCAM), the Terrain Camera (TCAM), the Low-Frequency Spectrometer (LFS), and the Lunar Lander Neutrons and Dosimetry (LND).
And, the rover is carrying the Panoramic Camera (PCAM), the Lunar Penetrating Radar (LPR), the Visible and Near-Infrared Imaging Spectrometer (VNIS), and the Advanced Small Analyzer for Neutrals (ASAN).
The huge amounts of science data and information these state-of-the-art space contraptions are capable of garnering will go a long way in helping researchers understand why the far side of our Moon is so vastly different from the side we’re familiar with.
For example, the lunar terrain on the tidally-locked near side is largely dark basaltic plains called the lunar maria, while the far side is mountainous and rugged and, hence, difficult to land anything on.
Since the Moon takes the same amount of time (28 days) to orbit our planet as it does to rotate once on its axis, we always get to see the same side of the natural satellite, with the opposite side forever hidden from view.
Chang’e 4 is also carrying a small experimental payload consisting of silkworm eggs and seeds to check how they develop in the lunar atmosphere.
Landing a spacecraft on the far side is a complex undertaking in itself, leave alone communicating with it, what with the Moon’s entire mass blocking the exchange of direct signals to and from Earth.
Obviously, China had to find a workaround to this problem before it could attempt the far side lunar landing, which it did by launching the Queqiao satellite in May.
The satellite is now placed in its orbit at the Earth-moon Lagrange point 2 beyond the Moon, ideally located to facilitate unobstructed communication between the mission control on Earth and Chang’e 4.
Lagrange points are basically orbital spots between two large celestial bodies where a smaller body is held in its orbital path by the opposing gravitational forces of the two larger bodies acting on it; to put it simply, it provides gravitational stability to relatively smaller objects.
China’s next lunar run will be the Chang’e 5 sample-retrieval mission, which the China National Space Administration (CNSA) started preparing for in October 2014 when it launched the Chang’e 5T1 mission to run atmospheric re-entry tests on the Chang’e 5 capsule.