PARIS — The successful July 10 launch of India’s PSLV rocket takes the commercial Earth observation business one step closer to the well-tested satellite telecommunications business model of leasing in-orbit capacity rather than buying imagery or pixels.
The launch placed five satellites built by Surrey Satellite Technology Ltd. (SSTL) of Britain into a polar orbit. Two of them were experimental satellites, one testing optical observation and the other a technique for satellites to deorbit themselves, clearing the orbital highways of debris.
SSTL reported that the satellites are all healthy in orbit.
The main payload was the three-satellite DMC3 constellation of 1-meter-resolution spacecraft built by SSTL as part of a commercial venture with anchor customer Twenty-First Century Aerospace Technology Co. (21AT) of Beijing.
The Chinese company, which bills itself as China’s first non-government-owned Earth observation imagery provider, has purchased the entire capacity on the DMC3 constellation for seven years.
The SSTL-21AT contract, valued at 110 million British pounds ($170.2 million at mid-2011 exchange rates), covered the expected construction, launch and insurance of the DMC3 spacecraft, as well as the use of all their data.
21AT was already a part of the SSTL-originated Disaster Monitoring Constellation of satellites contributed by several nations, with the Beijing-1 satellite launched in 2005. Beijing-1 had a ground resolution of 4 meters in black and white, 32 meters in color and a swath width of 24 kilometers. It was built to last five years and could swivel 30 degrees off its axis to take off-nadir images.
The three DMC3 satellites, using a new SSTL design, have a 1-meter-resolution imaging capability, 4 meters in color, with a 23.4-meter swath width. They are capable of pointing up to 45 degrees off nadir.
Called Beijing-2 by 21AT, the three satellites will be spaced 120 degrees apart at 647 kilometers in altitude over the next three months, enabling the constellation to revisit any point on Earth every 24 hours. The xenon-electric propulsion system is designed to keep the satellites operating for at least seven years.
In addition to adopting a telecommunications-tested sales model, the SSTL-21AT contract — formally blessed in 2011 by the British and Chinese heads of government — enabled the two sides to proceed without concern for U.S. technology-transfer rules relating to space hardware being exported to China.
SSTL had hoped the 21AT contract would be an inducement for another nation or company to purchase a fourth DMC3 satellite, which would increase revisit rates, provide in-orbit backup and permit 21AT to spread its capacity booking over four satellites instead of three.
Several nations, most recently Peru, have said securing immediate access to an in-orbit constellation while they are waiting for their own satellite is a high priority. Airbus Defense and Space, which owns SSTL but operates on an arm’s-length basis, won the Peruvian contract — besting SSTL, among others — in part by offering access to Airbus’s current Spot and Pleiades satellites.
Operating from India’s Satish Dhawan Space Centre, the July 10 PSLV launch was the ninth using the vehicle’s “XL” configuration. It was also a rare PSLV flight carrying only commercial, non-Indian payloads.
SSTL contracted with Antrix, the commercial arm of the Indian Space Research Organisation, for the launch. Each DMC3 satellite weighed 447 kilograms. The CBNT-1 satellite weighed 91 kilograms, and the D-OrbitSail satellite — which will deploy petals to slow its orbital speed, forcing a reentry — weighing 7 kilograms.
ISRO said the launch required the development of a special satellite dispenser that put the three DMC3 satellites on top, with CBNT-1 and De-OrbitSail at the bottom of the structure.
The fact that small-satellite builder SSTL placed all three DMC3 satellites on a single PSLV while remaining within its program budget illustrates both the vehicle’s reliability and its low cost. The vehicle has a 100-percent success rate since its introduction in 2008.
The Indian government in May approved a budget of 20.9 billion Indian rupees ($484 million at May 2015 exchange rates) to build and launch 15 PSLV rockets between 2017 and 2020.
Even when accounting for a profit margin added by Antrix, the bulk purchase, at the equivalent of $33.3 million per launch — plus any special work needed such as payload-dispenser gear — makes the PSLV a bargain given today’s competition.