PARIS — Boeing will build the first of Intelsat’s Epic series of high-throughput telecommunications satellites under a contract to be announced the week of Sept. 3, Intelsat and Boeing officials said.
The satellite, IS-29e, will provide between 25 and 30 gigabits per second of bandwidth for fixed and mobile customers in North and South America and over the North Atlantic maritime and aeronautical routes.
While 30 gigabits per second is much less than what is provided by several satellites deployed for consumer broadband, it is an unprecedented throughput for its intended customers, Intelsat Chief Technology Officer Thierry Guillemin said.
In an interview, Guillemin said IS-29e, with around 15 kilowatts of power available for its payload, will carry a roughly equivalent number of C- and Ku-band transponders. The Ku-band will be more frequently used than the C-band to deliver high-speed capacity through narrow spot beams that facilitate the reuse of the frequency.
Guillemin said users of mobile satellite capacity want to tap into spot beams for high-bandwidth applications, while also accessing wide-beam coverage for television broadcasts.
A second Epic satellite, IS-33e, is expected to be ordered in the coming months to fill out Intelsat’s announced capital spending plan. Guillemin said the coverage of IS-29e and IS-33e has been configured such that the two satellites cover most of the world’s mobile markets.
The Epic satellites will add a layer of higher-speed capacity over Intelsat’s existing mobile capacity, which consists of 10 beams on seven standard-power satellites, the last of which will launch in 2013.
Guillemin said Washington- and Luxembourg-based Intelsat had not yet decided on the prime contractor for IS-33e, but that several manufacturers appear to be able to offer similar packages that give C- and Ku-band a throughput that up to now has been associated mainly with Ka-band, and mainly for consumer Internet services.
Craig R. Cooning, vice president and general manager of Boeing Space and Intelligence Systems, said in a written response to Space News questions that bringing high throughput to C- and Ku-band is not markedly different from Ka-band.
“The fundamental principles are the same,” Cooning said Aug. 31. “However, there are inherent differences in the frequencies that also factor into the capability. Hardware cost and availability is generally better for C- and Ku-band than for Ka-band.”
Intelsat is able to offer such high bandwidth in the C- and Ku-bands because of its stable of orbital slots, some of which have been allocated far more broadcasting frequency by international regulators than the company is using.
For El Segundo, Calif.-based Boeing, the Intelsat order is the final chapter in a four-satellite contract signed in mid-2009 that permitted the manufacturer to inaugurate what is now its showcase commercial product, the updated 702B platform and its several variations.
The company has since booked an order for three high-power 702 satellites, all in Ka-band, from mobile services satellite operator Inmarsat of London. More recently, Boeing introduced an all-electric variant of the 702 line, the 702SP, that offers substantial weight savings on satellites by replacing chemical propellant with an all-electric design.
The weight savings then can be used to lower launch costs. The first two 702SP customers, Asia Broadcast Satellite (ABS) of Hong Kong and Satmex of Mexico, have teamed up to purchase a total of three or four 702SP satellites, with the first two to be launched together on a Falcon 9 rocket operated by Space Exploration Technologies Corp. of Hawthorne, Calif.
Fitting these two satellites in a single Falcon 9 would not have been possible without an all-electric propulsion system.
Intelsat and other prospective customers of the all-electric-propulsion design have questioned whether the several months it takes for one of these satellites to climb from the transfer orbit where it is dropped by its launch vehicle into final geostationary position might not expose its solar arrays and electronics to excessive radiation found at the altitudes along the way.
A satellite using conventional chemical propellant burns several hundred kilograms of fuel to reach its final orbit in a matter of days.
Cooning said Boeing has accounted for this in its 702SP design.
“Boeing has significant experience with MEO [medium Earth orbit] satellites such as GPS and ICO, which face much more severe environments than the six months of orbit-raising for the 702SP,” he said. ICO was a proposed 12-satellite MEO constellation on which Boeing was prime contractor. Only one spacecraft was launched and the business has since shut down with the remaining satellites in storage.
“This experience has been leveraged for the 702SP,” Cooning said. “We have designed the solar array to account for the time spent in transfer orbit, and incorporated the appropriate shielding into the spacecraft to protect the electronics.”
Cooning said Boeing is pursuing “multiple opportunities” for additional 702SP orders that have arisen since the ABS/Satmex contract announced in March. “The ability to dual manifest on the Falcon 9, and the available payload power of around 8 kilowatts, is economically compelling,” he said.
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