Recently China has announced plans to launch an “artificial moon” into our skies by 2020. And, as crazy as that sounds, it’s not actually the first time something like this has been attempted. So, How China is going to lit up the sky?
As reported in China Daily, China plans to launch an “illumination satellite” into orbit above the city of Chengdu. Well actually, four illumination satellites. The first as a proof of idea in 2020 and the following three as the real deal in 2022. There aren’t a ton of details about the satellites themselves yet, like how big they are or what they will be made of, but we do know they will be covered with a “coating which is reflective similar to the moon’s”.
How China is going to lit up the sky?
At the proposed distance of 500km, a single satellite is expected to illuminate an area between 10 and 80 km, with light around “8 times brighter” than the moons. On the off chance that all goes to design, the scientists hope the moons will replace road lights in urban regions and save millions of the city, in power costs every year. They could likewise help light up streets amid cataclysmic events and power outages.
Those same benefits are what prompted Russia to try something similar 20 years ago, in what was called Project Znamya. In 1993, Russia successfully deployed its own prototype of an illumination satellite, about a 20-meter reflective film that unfolded in space. For a few hours, it orbited a couple of hundred meters above the earth, beaming a 5km wide spotlight over Europe.
In any case, that light just moved at around 8 km/hour, which means the vast majority just observed a blaze in the sky as it passed. Eventually, it fell out of orbit and burned up on re-entry. The Russians tried this again a few years later, this time with a 25-meter mirror. However, the satellite failed to deploy, and it quickly fell out of orbit. There were plans to install a third, considerably greater mirror, yet the project faced genuine budgeting issues and was later relinquished.
China’s Plan on Project
So, China’s plan is essentially picking up where Russia left off, taking note of their mistakes and making something that will actually work. Well, as critics have been quick to point out, that doesn’t appear to be the case. The first, and likely biggest, issue with China’s proposed plan concerns the height of the orbit.
In order for a satellite to track a single city on earth, it would need to be in a geostationary orbit, about 36,000 km above the earth. At the proposed 500 km, China’s satellites would face the same problem that Russia’s did, whipping around the earth, quickly lighting up random places for a fraction of a second as they go, which isn’t exactly the goal.
Also Read: Surviving First Moon Landing
And even if they meant to say 36 thousand, a satellite at that height would need to be extraordinarily large which should be hundreds of meters across to reflect much back to earth. And while it is not specified how big China’s satellite will be, launching something big enough could be prohibitively difficult.
Critics also pointed out the plan has no mention of any sort of thrusters or fuel onboard these satellites. And that would probably be a necessity since out in space, the satellites, (like the Russian mirrors) will experience drag and solar radiation that will eventually push them out of orbit. The cost of the initial fuel and subsequent refueling missions could outweigh any savings in electricity costs on Earth.
Reportedly, researchers at several universities and institutes have looked over the plan and have given it the okay for trial, so maybe we just don’t have all the details. If that’s the case, and the plan does work, should we be worried? Many scientists have expressed concerns that these satellites will amplify the light pollution problems we already have.
Excess light from cities today alters night cycles of animals, the sleep cycles of humans, and disrupts astronomers’ view of space. And a project of this scale will likely make those problems worse. It’s not clear in the reports whether the Chinese government has given these plans any sort of official backing. So, I suppose, for now, we’ll just have to wait and see if any new moons light up the sky. It’s going to be a technological marvel when we will see how China is going to lit up the sky.