10 July 2015 – Surrey Satellite Technology Ltd (SSTL) has confirmed the launch on 10 July 2015 of three 1-metre resolution optical Earth Observation satellites that will form the DMC3/TripleSat Constellation. The satellites were placed into a 651km sun-synchronous Low Earth Orbit by a PSLV-XL launch vehicle from the Satish Dhawan Space Centre, Sriharikota launch site in India. The launch agency is ANTRIX and the Indian Space Research Organisation (ISRO).
Sir Martin Sweeting, Executive Chairman of SSTL, said “These new satellites are the latest and the most advanced of SSTL’s Earth Observation spacecraft mounted on a PSLV rocket dedicated to our mission – it was really exciting to be able to push the green button for launch and see them off into orbit!”
Following confirmation of separation of all three spacecraft from the launch vehicle, the ground station at SSTL’s Spacecraft Operations Centre in Guildford, UK and at Svalbard successfully established contact with the satellites. SSTL’s engineers will now begin the commissioning of the platform systems on board the three satellites, with commissioning of the imaging payloads commencing once platform commissioning is complete.
The three spacecraft use the 450kg SSTL-300S1 series platform. The agile SSTL-300S1 platform provides 45 degree fast slew off-pointing and is capable of acquiring multiple targets in one pass using multiple viewing modes. The very high resolution imager on board the satellites was designed and manufactured by SSTL and will provide 1 metre ground sampling distance (GSD) in panchromatic mode, and 4 metre GSD in multispectral mode, with a swath width of 23.4km.
The three satellites will be phased 120 degrees apart around the same orbit using their on board propulsion systems within three months after the launch; thus with off-pointing capability, the DMC3/TripleSat Satellite Constellation will be able to target anywhere on Earth once per day. In addition, the wide swath width of the satellites provides the best combination of spatial resolution and time resolution – aiming at stimulating operational monitoring applications, such as urban planning and intelligent management, based on changes detected by timely and regular cloud-free, very high-resolution imagery.
The Twenty First Century Aerospace Technology Company Ltd (21AT), a commercial Earth observation satellite operator based in Beijing, has bought the imaging capacity of the three satellites. The cooperative contract for the DMC3/TripleSat Constellation was signed in London in 2011 and witnessed by the UK Prime Minister, and China’s Premier.
Mme Wu Shuang, CEO & President of 21AT, said: “I am very glad that the three satellites are in orbit and have started communication with the ground station. It is the first step of our long march and we are looking forward to the commencement of our BJII data services following the completion of the commissioning of the DMC3/TripleSat Constellation.”