The Chinese are great at making knockoffs. This time they’re after a bigger prize than usual. They’re currently looking at the idea of launching an artificial moon into orbit by 2020 to illuminate city streets after dark.The man-made moon would hang in synchronous orbit over the city of Chengdu, the capital of China’s southwestern Sichuan province, according to a report in Chinese state media. The satellite would have a reflective coating and cast light from the sun back to Earth, where it will supplement streetlights at night. They think it would be about eight times more luminous than the Moon, and would orbit a lot closer to Earth; about 500 km (310 miles) away, compared to the moon’s 380,000 km (236,000 miles).
It’s not going to light up the whole sky, though. Wu Chunfeng, chief of the Tian Fu New Area Science Society, told China Daily. “Its expected brightness, in the eyes of humans, is around one-fifth of normal streetlights,” or roughly the equivalent of a full moon, assuming a cloudless sky.
If it works, they’ll launch three more of them by 2022. The artificial moons would supposedly be repositionable and the light from them could be aimed to an accuracy of a few dozen meters. They will have adjustable mirrors, all controllable from the ground, to be engaged and disengaged at all.
The math all apparently works. Whether the Chinese space program can actually build such a thing and make it work remains to be seen. Whether they can deploy this stuff without actually trashing important parts of their own ecosystem also remains to be seen, and they’re investigating this aspect of it. Frankly, nobody knows how much this will disrupt animal and plant life, nor how it will affect the natural sleep patterns of the humans exposed to it.
There was a Russian project in 1993 to do the same thing, but the launch vehicle for the 65 foot diameter space mirror (the project was named “Banner”) misfired at launch and the entire project was soon canceled due to budget issues.
There are so many ways this could go sideways, and even if they launch it, nobody exactly knows how well it will work in practice or what unintended consequences may ensue.