China launched three commercial remote sensing satellites to be used for high definition video in what is known as the Jilin-1 constellation. The launch took place at 04:50 UTC on Tuesday from the Taiyuan Satellite Launch Center’s LC16 Launch Complex using the Long March-6 (Chang Zheng-6) launch vehicle.
The Jilin-1 constellation was developed in China’s Jilin Province and is the country’s first self-developed remote sensing satellite for commercial use.
Jilin-1 consists of several satellites that will provide data to commercial clients to help them forecast and mitigate geological disasters, as well as shorten the timescale for the exploration of natural resources.
Jilin, one of the country’s oldest industrial bases, is developing its satellite industry in a new economic drive. The province plans to launch 60 satellites by 2020 and 138 by 2030.
The first phase of the constellation saw the launch of the first three Jilin-1 satellites (that are also known as Lingqiao-1). Jilin 1-01 and Jilin 1-02 were launched on October 7, 2015, by a Long March-2D launch vehicle out of the Jiuquan Satellite Launch Center, while Jilin 1-03 was launched on January 9, 2017, using a Kuaizhou-1A solid launch vehicle.
Between 2018 and 2019 there are plans to have 16 satellites in orbit, completing a remote sensing network that will cover the entire globe and will be capable of a three to four hours update in the data provided.
From 2020, the plans point to a 60 satellites orbital constellation capable of a 30 minutes update in the data provided.
From 2030, the Jilin constellation will have 138 satellites in orbit, forming an all-day, all-weather, full spectrum acquisition segment data and a capability of observing any global arbitrary point with a 10 minutes revisit capability, providing the world’s highest spatial resolution and time resolution space information products.
The Jilin-1 remote sensing satellites are designed to capture videos with a ground resolution better than 1.0 meters and with a swath of 11 km × 4.5 km. The operational lifespan of the satellites is 3 years. The launch mass is 95 kg.
Launch vehicle and launch site:
The CZ-6 Chang Zheng-6 is a liquid-propellant, small-load space launch vehicle developed by Shanghai Academy of Spaceflight Technology (SAST).
The launch vehicle is based on the 3.35m-diameter boosters, which have been developed as a strap-on booster for the CZ-5 family of SLV.
The core stage consists of a single 120t-thrust YF-100 engine that burns oxygen and kerosene (LOX/Kerosene) propellant, which causes less pollution compared to the UDMH/N2O4 (nitrogen tetroxide) propellant currently in use.
The Long March-6 is designed for small-load launch missions, with a sun-synchronous orbit (700km SSO) capability of 1,080 kg.
In September 2009, the Chang Zheng-6 launch vehicle development program was officially approved by the Chinese Government and the first flight was expected to take place in 2013. SAST was tasked with the development of the new launch vehicle in July 2008.
Overall length is 29.237 m with a total mass at liftoff of 103,217 kg. Dry mass of the three stages combined is 9,020 kg. Fairing diameter is 2.25 m / 2.6 m, and the vehicle is capable of launching a payload of 1,080 kg to a 700 km SSO orbit (500 kg if only Chinese tracking stations are used).
The first stage has a 3.35 meter diameter and is equipped with a single YF-100 engine, consuming 76,000 kg of kerosene RP-1/LOX. The YF-100 engine is capable of a ground thrust of 1,177 kN and a ground specific impulse of 2.9 km/s. Burn time is 155 seconds. The first stage uses four 1000 N thrusters for roll control.
The second stage has 2.25 meter diameter and consumes 15,150 kg of kerosene RP-1/LOX. It is equipped with a YF-115 developing 147.1 kN (sea level) or 176.5 kN (vacuum), with a vacuum specific impulse of 3.35 km/s. The second stage uses four 25 N thrusters for roll control.
The third stage is equipped with four engines with 4 kN (each), along with eight 100 N thrusters for attitude control. The engines are powered by a mixture of kerosene and hydrogen peroxide.
Situated in the Kelan County in the northwest part of the Shanxi Province, the Taiyuan Satellite Launch Center (TSLC) is also known by the Wuzhai designation. It is used mainly for polar launches (meteorological, Earth resources and scientific satellites).
The launch center has two single-pad launch complexes, a launch area for the new Long March-6 rocket, a technical area for rocket and spacecraft preparations, a communications center, a mission command and control center, and a space tracking center.
The stages of the rocket were transported to the launch center by railway and offloaded at a transit station south of the launch complex. They were then transported by road to the technical area for checkout procedures.
The launch vehicles were assembled on the launch pad by using a crane at the top of the umbilical tower to hoist each stage of the vehicle in place. Satellites were airlifted to the Taiyuan Wusu Airport about 300km away and then transported to the center by road.
The TT&C Centre, also known as Lüliang Command Post, is headquartered in the city of Taiyuan, It has four subordinate radar tracking stations in Yangqu (Shanxi), Lishi (Shanxi), Yulin (Shaanxi), and Hancheng (Shaanxi).