An Indian PSLV launcher sent France's high-resolution SPOT 6 Earth observation satellite to orbit Sept. 9, the second of four spacecraft designed to form a complete optical constellation that will offer daily images of every point on the globe in high and very-high resolution.
Launched from the Satish Dhawan Space Center in India, the EADS Astrium-built SPOT 6 joins the company's very-high-res Pleiades 1A satellite in orbit. Lofted in December 2011 atop a European Ariane 5, Pleiades 1A will be paired next year with its twin, Pleiades 1B, followed by the launch of SPOT 7 in early 2014. Together the four spacecraft will comprise an Earth observation system operated by Astrium Satellites and exploited by the company's satellite-product distributor, Astrium Services.
Once all four spacecraft are working together in orbit, each point on the globe will be seen once daily, with SPOT 6 and 7 offering a wide-picture view at 1.5 m over a 60-km swath and Pleiades 1A and 1B observing the same area with a narrower field of view in greater detail at 50-cm resolution.
“With four satellites phased 90 degrees apart in the same heliosynchronous quasi-polar orbit, we will be able to offer our customers geo-information products in record time, in as little as six hours,” says Astrium Services CEO Eric Beranger. “With four satellites, we obviously have more freedom in terms of the revisit interval, for better change detection or faster coverage. Users can choose between very-high-resolution data capture at a specific point and high-resolution data capture over a larger area. We can also combine the two, of course. For instance, in case of flooding, SPOT 6 can provide the big picture and Pleiades will bring the focus over the most populated or damaged areas.”
Designed to ensure service continuity of France's SPOT 4 and SPOT 5 satellites, which have been operating since 1998 and 2002 respectively, the SPOT 6 and 7 ground and space segments have been enhanced to provide better reactivity -- from satellite tasking to product delivery -- and collection capacity. Based on the newly designed Astrium Astrosat 500 MklI platform, SPOT 6 and 7 are lighter (weighing 720 kg against SPOT 5’s 3 metric tons), due in part to the inclusion of silicon carbide, a new detector for the instrument and new avionics for the satellite. Together SPOT 6 and 7 will cover 6 million square km per day over the course of their 10-year service life.