Latest news with #geostationaryorbit
South China Morning Post
13-07-2025
- Science
- South China Morning Post
China's Shijian satellite pair appears to dock in orbit for historic refuelling mission
Two Chinese satellites may have docked in geostationary orbit for a historic refuelling mission, an autonomous satellite servicing feat the United States has yet to achieve. China's Shijian-21 and Shijian-25 'appeared visually merged in optical sensor data' between July 2 and July 6, US-based space situational awareness software provider COMSPOC said on Saturday in a social media post. 'Given the prolonged RPO time, SJ-21 and SJ-25 may have docked,' it said, using the acronym for 'rendezvous and proximity operations'. The two probes were observed carrying out such operations in geosynchronous orbit in June and July 'with multiple close approaches', it added. The first close approach was observed on June 11, when Shijian-25 continued its 'steady drift towards' Shijian-21, and the two came within 1km (0.6 mile) of each other on June 13 before separating 90 minutes later, according to COMSPOC. US surveillance satellites USA 270 and USA 271 flanked the Chinese satellites from east and west at the time and were positioned for optimal viewing angles, the company said. According to optical tracking images from Swiss space surveillance firm s2a systems, the Chinese satellites, both orbiting at an altitude of 35,786km (22,236 miles) above the equator, carried out another round of close-proximity operations on June 30.
South China Morning Post
26-06-2025
- Science
- South China Morning Post
China's new Dawn: Pan Jianwei reveals high-orbit quantum satellite for global network
China is developing the world's first high-orbit quantum communication satellite to enable more efficient, globally accessible quantum networks and lay the groundwork for redefining the international standard of the second, according to Pan Jianwei , the country's 'father of quantum'. Set to launch around 2027, the satellite will operate in geostationary orbit more than 35,000km (21,700 miles) above the Earth, Pan revealed during a pre-recorded keynote speech at a conference in Germany this month to mark the centenary of quantum mechanics. The satellite will carry an optical atomic clock and serve as a new platform for quantum metrology research, including efforts to improve the short-term stability of atomic clocks through global entanglement distribution, and potentially pave the way for a redefinition of the International System of Units (SI) base unit of time – the second. 11:05 Space race elevates Asia in new world order Space race elevates Asia in new world order The satellite – named Dawn – follows Micius , the world's first quantum satellite that was launched into low Earth orbit in 2016 by Pan's team at the University of Science and Technology of China. Pan revealed the satellite's name during a live Q&A session with more than 300 quantum physicists, including four Nobel laureates, who gathered on the island of Helgoland for the week-long meeting. Dawn was designed to extend entanglement distribution distances to over 10,000km, he said. 'A high-orbit satellite is incredibly powerful. It can simultaneously see two locations on Earth that are 10,000km apart,' he told state broadcaster CCTV in May. 'That makes it possible for us to establish key distributions between Beijing and South Africa.' Entanglement distribution from high orbit could also take place around the clock, thanks to the satellite's stationary position over Earth. 'That provides continuous coverage and ensures secure communications 24/7,' Pan told Chinese state broadcaster CCTV. He had previously told Chinese media that long-distance quantum communication through fibre-optic cables was limited by signal loss.
