Scientists in China are developing a fleet of small satellites for cutting-edge astronomical observations, traditionally the realm of large and expensive space telescopes. The Chinese mission envisions more than 100 microsatellites, each equipped with a smaller and lighter version of a normal X-ray telescope, to monitor the highly energetic and short-lived violent phenomena of deep space. The approach is in sharp contrast to the trend towards ever-bigger telescopes which can look deeper into space and time. The US$10 billion James Webb telescope – launched in December to look for the first light in the universe after the Big Bang – took more than two decades to build at up to 10 times its expected cost. The CATCH – for Chasing All Transients Constellation Hunters – team aims to test its basic design by launching a pathfinder satellite next year, followed by 10 orbiting satellites to test out the intelligent control system. Tao Lian, who is leading research and development of key technologies for the CATCH mission, said if these first steps prove successful the team will propose deploying the entire constellation around the year 2030. Tao, from the Institute of High Energy Physics at Beijing’s Chinese Academy of Sciences, said the estimated budget for each satellite is 10 million yuan (US$1.6 million), half of which will go on launch costs. She forecast that costs could be significantly lowered in a few years, with cheaper satellites and launch services provided by private companies, thanks to the fast-growing commercial space sector. The greatest challenge will be to coordinate the satellites as they work individually and collectively, according to Yin Qianqing, another member of the CATCH team. Each “smart” microsatellite – weighing about 30kg (66lbs) – will be able to automatically trigger detection and tracking while in orbit, choose targets efficiently and match its observations with an astronomical phenomena database, he said. Compact mirrors that mimic the structure of a lobster’s eye are being developed for the microsatellites in partnership with North Night Vision Technology, a global optical products supplier based in Kunming, in the southwestern province of Yunnan. The complex structure of the mirrors is designed to capture light from different angles in the search for events ranging from supernova explosions to the emergence of black holes, which can be detected in the X-ray sky through the extremely hot gases they produce at temperatures above a million degrees Celsius. Until recently, there was little serious discussion on the suitability of small satellites for astronomy, because of their strict size, mass and power limits. Most observations rely on the collection of light particles and the larger the mirror, the more it can collect. This has largely limited small satellites to Earth observations and educational settings, but there have already been examples of successful deep space discoveries using these small and much cheaper devices. Astrophysicist Jonathan McDowell, at the Harvard-Smithsonian Centre for Astrophysics, said the Canadian-European BRITE mission uses a network of five nanosatellites to measure brightness variations in very bright stars. “It’s true that the size of a telescope matters, but there are areas where small satellites can really help in astronomy,” he said. And last November, a team led by Tsinghua University in Beijing reported detecting a gamma ray burst – the most energetic explosion in the universe – with a 10cm (3.9 inches) CubeSat. The detection, reported in The Astrophysical Journal, was confirmed by large gamma-ray telescopes including Nasa’s US$700 million flagship observatory Fermi Gamma-ray Space Telescope.