In March 2012, when Boeing announced the sale of the world’s first all-electric satellites, the company sparked a trend in the commercial telecom industry, lighting a fire under competitors in Europe and Asia as they scrambled to catch up.
But two years on, Boeing has yet to announce a follow-up deal for its xenon-ion fueled 702SP satellite bus, while European competitors once thought to be years behind the curve are gaining ground.
Within months of the Boeing announcement, the European Space Agency (ESA) unveiled plans to fund codevelopment of the new Electra all-electric satellite bus with European industry. ESA also said it would help finance the next generation of European satcom buses with manufacturers Airbus Defense and Space and Thales Alenia Space, incorporating an electric propulsion option to raise the new platform, known as NeoSat, into orbit.
But with these developments not expected to enter service for several years, Airbus has pressed ahead with a near-term answer to Boeing, evolving its legacy Eurostar E3000 platform to include an all-electric variant aimed at customers seeking higher payload power and greater flexibility than the 702SP offers today.
In July, Airbus Defense and Space nailed two deals for such spacecraft, including a contract with Paris-based fleet operator Eutelsat to build Eutelsat 172B, the first European communications satellite equipped with electric plasma thrusters designed to raise, maneuver and position itself in geosynchronous orbit.
“Never underestimate us,” says Eric Beranger, head of space system programs at Airbus Defense and Space. “I said after the Boeing announcement in 2012 that we could also provide full electrical transfer capability for satellites, and what you are seeing today is the proof that I was not lying.”
Beranger says Airbus Defense and Space has seven satellites in orbit that use electrical propulsion, albeit for station-keeping only. These spacecraft have provided the company ample data on the technology, which it has used to adapt the Eurostar E3000 for all-electric orbit transfer.
Slated to launch on an Ariane 5 ECA rocket in the first half of 2017, the Eutelsat 172B will be equipped with an impressive 11-kw payload packed into a diminutive 3,500-kg (7,700-lb.) satellite. Located at 172 deg. E. Long., the spacecraft will feature 14 C-band and 36 Ku-band transponders, as well as a high-throughput Ku-band payload customized for aeronautical inflight connectivity over the Pacific Ocean with an overall throughput of 1.8 gbps.
Beranger says a comparable satellite using chemical propulsion would typically run close to 6,000 kg, requiring a heavy-lift Proton or Zenit launcher or a position in the upper bay of the dual-payload Ariane 5. Given its slight launch mass, however, Beranger says Eutelsat 172B is sized to ride in the lower—and far less costly—position available on the ECA configuration of the Ariane 5.
“We are the first in Europe, and even the first in the world, to demonstrate electric propulsion for satellites of this size,” Beranger says.
The Eutelsat announcement followed an Airbus Defense and Space contract signed in July with fleet operator SES of Luxembourg for SES-12, a hybrid chemical/electric satellite that is also based on the Eurostar E3000 platform and will likewise use electric plasma thrusters for orbit-raising and maneuvers. The most powerful satellite SES has ordered to date, the 5,300-kg spacecraft will carry 68 high-power Ku-band transponders and eight Ka-band transponders to combine traditional wide-beam coverage with high-throughput spot beams and a new digital transparent processor for anti-jamming capabilities and much greater payload flexibility.
Depending on the launch vehicle, which SES says will be announced at a later date, SES-12 will need 3-6 months to propel itself to an operating orbit at 95 deg E. Long. Eutelsat 172B, on the other hand, will need just four months in transit, nearly halving the time required for Boeing’s 702SP, which uses lightweight, low-power xenon-ion thrusters developed by L-3 Electron Technologies.
Asia Broadcast Satellite (ABS) of Bermuda and SatMex of Mexico (now Eutelsat Americas), were well aware of the platform’s time to orbit when they signed on for a total of four Boeing 702SP spacecraft in 2012.
Packing less oomph than the all-electric variant of Airbus Defense and Space’s Eurostar E3000, the 702SP offers just 3-8 kw of power, though it can accommodate up to five reflectors and features a next-generation avionics architecture that simplifies operations and provides easier access to data for evaluation of the spacecraft’s health.
While the 702SP’s lengthy transit time to orbit creates a lag between launch and the satellite’s ability to generate revenue, the upside for the fleet operator is that the 702SP can stack in pairs under the fairing of most rockets capable of carrying two satellites at a time, including the SpaceX Falcon 9 v1.1 rocket. In fact, the dual-launch scenario with the Falcon 9 is key to the 702SP’s success, an approach Boeing says saves fleet operators 20% of the cost to launch atop what is already the lowest-priced rocket in its class.
Although Boeing has not announced additional 702SP commercial sales, the company is finalizing a potential deal with an Indonesian operator that could be announced this year. The company also has signed a contract with an unnamed government customer for an undisclosed number of 702SP spacecraft, and several campaigns are underway that could result in sales of more 702SP spacecraft, with a contract to be announced possibly this quarter.
In the meantime, rival manufacturers are taking varied approaches to future spacecraft bus developments that would include more electric-propulsion options. Thales Alenia Space is planning to introduce an all-electric satellite platform starting in 2016, while Lockheed Martin Space Systems is working on an all-electric variant of the venerable A2100 satellite bus using weightier Hall effect thrusters that could offer shorter transit time to orbit.
Space Systems/Loral is also supplying an electric-propulsion option for orbital transfer, but it sees the market evolving to favor hybrid solutions with higher payload power and more rapid ascent to orbit. Meanwhile, Orbital Sciences’ new GeoStar-3 satellite will offer 60% more power and a 30% boost in payload mass but will draw on electric propulsion for station-keeping only.
Something ISRO must consider. While we wait for full commercialisation of various versions of GSLV, this might be a way to deliver more capacity without focusing on throw weight.