MOSCOW, Jan. 21 (Xinhua) -- A Russian startup has just revealed plans to place massive billboards in the space, which might cover a potential audience of 7 billion on earth.

The space billboards would be composed of tiny satellites, each equipped with a reflective sail about 9.15 meters in diameter. These "cubesates" would orbit at an altitude of about 400 km, and reflect the sunlight to form luminous words or logos visible from the earth, according to the company, StartRocket.

StartRocket CEO Vladilen Sitnikov compared this project to that of Elon Musk and Peter Beck. "After the success of SpaceX, I assumed that everything is possible. In January 2018, when the American space company Rocket Lab launched the 'disco ball' into space, I also decided to try," the company's website quoted him as saying.

According to Sitnikov, the images formulated by those "cubesates" will be visible for all the inhabitants of the planet with a frequency of ten or more times per day. The space billboards will stay in orbit for a year before burning up in the atmosphere.

Despite the company's ambitious plan to test launch the satellites in January 2021, some experts have raised scientific and environmental concerns about the project.

"Putting more satellites up there is going to cause more opportunities for collisions, and we don't want that happening," John Crassidis, a professor of mechanical and aerospace engineering at the University at Buffalo told the U.S. broadcaster NBC. "My biggest issue is that these objects are going to become space junk."

Other concerns include whether or not those billboards would increase the level of light pollution throughout the world, and the complex processes it takes to get the approval from regulatory agencies.