On 31 March 2018, at 11:22 a.m Beijing time (UTC+8), China launched three remote sensing satellites from the Gaofen-1 series using the Long March 4C, from Taiyuan Satellite Launch Centre.
The launch saw Gaofen-1 Nos. 2, 3, and 4 being placed in the Sun Synchronous Orbit (SSO) to join Gaofen-1 No.1, which was launched in 2013. According to the Chinese space programme’s main contractor, the China Aerospace Science and Technology Corporation (CASC), the launch yesterday will form China’s first high-resolution remote sensing constellation used for commercial purposes.
The three satellites launched yesterday will enable 15 days’ global coverage, with a 2-day revisit period, with a 2-m full colour resolution, and an 8-m spectral imagery resolution.
When combined with Gaofen-1 No., the global coverage period will be reduced to 11 days, with a 1-day revisit period. The four-satellite constellation will be used for terrestrial mapping and monitoring, and will be able to attain a 1:25,000 to 1:50,000 scale.
The satellites were developed by the Aerospace Dongfanghong Satellite Co., each with a mass of approximately 800kg and a design life of 6 years. With these satellites, China hopes to reduce reliance on foreign high-resolution satellite imagery by 90%. The satellite images acquired by the new constellation will most likely by distributed internationally as well.
This was China’s second launch in 2 days, and its third in less than 2 weeks. The day before, China launched a pair of BeiDou-3 navigation satellites from the Xichang Satellite Launch Centre, using a Long March 3B.