China has begun construction of a mega constellation that will eventually consist of nearly 14,000 satellites, but the launch of the first 18 is already sparking concerns from astronomers about their impact on the night sky.
The Qianfan mega constellation is intended to beam internet to the ground and rival the likes of SpaceX鈥檚 Starlink constellation, which already boasts more than 6000 satellites and has doubled the number of active satellites in space.
When SpaceX first began launching satellites in 2019, astronomers quickly realised that they were bright enough to hamper optical and radio views of the universe. The firm has since worked to voluntarily reduce the brightness of its satellites, both by coating them in a mirror-like material to and by changing the orientation of their solar panels.
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SpaceX鈥檚 efforts have been somewhat successful, but now the same problem has arisen with Qianfan, which is operated by Shanghai Spacecom Satellite Technology (SSST), a government-backed firm. After the launch of the first 18 satellites in August, Anthony Mallama at the International Astronomical Union and his colleagues found they were brighter than all but 500 stars in the sky. This means they can leave bright streaks in astronomical images taken by telescopes, potentially harming the scientific study of the universe.
鈥淭he Qianfan satellites in this first batch are bright enough to be seen by the unaided eye,鈥� says Mallama. 鈥淭hey will adversely impact research astronomy and the aesthetic appreciation of the night sky at their current brightness.鈥�
China could reduce the brightness of its Qianfan satellites in a similar manner to SpaceX, says Mallama. However, there are no global regulations requiring the country to do so. 鈥淚t鈥檚 difficult to know whether they are listening to the concerns of astronomers,鈥� he says. SSST, which has raised $933 million (拢711 million) to build its constellation, didn鈥檛 respond to a request for comment.
Qianfan is initially intended to serve China鈥檚 domestic needs for space-based internet in remote or underserved areas, says at the Secure World Foundation in the US, though SSST may later attempt to sell services internationally. 鈥淭hey鈥檙e trying to catch up first, then maybe compete later,鈥� he says. Starlink already has quite a head start, with in over 100 countries.
The potential impact on the night sky 鈥渞aises the need for greater policy and industry attention to the responsible operations of large constellations鈥�, says Christensen. However, he notes that global regulation is unlikely, and any direction will need to come at a national level.
鈥淐hinese operators want to be viewed as responsible space actors, and they certainly see SpaceX as the leader to emulate,鈥� says Christensen. 鈥淪o the fact that SpaceX and other operators have engaged in this mitigation work may lead to Chinese operators also viewing it as important.鈥�
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