WASHINGTON — Orbital Sciences Corp.’s new GeoStar-3 satellite product, which offers a 60 percent increase in power and a one-third increase in payload mass compared to the GeoStar-2, will use electric power for in-orbit station keeping but not for orbit-raising, Orbital Chief Executive David W. Thompson said March 10.
Addressing the Satellite 2014 conference here, Thompson said satellite operators have shown little demand for an all-electric satellite mainly because it would take months, rather than a week, to reach final geostationary operating position.
The satellite industry has gone two years since Satmex of Mexico and Asia Broadcast Satellite (ABS) of Hong Kong joined forces to inaugurate Boeing Space and Intelligence Systems’ all-electric 702SP product with a four-satellite order.
The order was twinned with launches, two satellites at a time, aboard Space Exploration Technologies Corp. Falcon 9 rockets. The first launch is scheduled to occur in early 2015, with the second late that year.
Since then, no more all-electric satellites have been contracted despite what satellite builders, operators and launch service providers describe as a wave of interest in the technology.
The Boeing satellites will take six to eight months to reach final geostationary orbit. A different electric-power propulsion system, the SPT-140, being offered by manufacturer Space Systems/Loral promises to shave perhaps two months off that, but it is still longer than some satellite operators want to take in post-launch maneuvers before generating revenue.
In addition to the longer time needed to reach final geostationary operating orbit, satellite operators are also concerned that, should they wish to move their in-orbit satellites from one slot to another during their 15- to 20-year service lives, the maneuver would take much longer with electric propulsion.
Space Systems/Loral President John Celli said the industry is most likely to settle on a hybrid solution that saves some of the launch mass of a satellite through electric propulsion, but retains conventional chemical propellant to speed the arrival of the satellite to final operating position.
Airbus Defence and Space of Europe is offering an all-electric option this year, and Thales Alenia Space will have an all-electric product starting in 2016. Lockheed Martin Space Systems has its own all-electric design, which offers a quicker delivery to geostationary orbit but using a heavier electric propulsion system.
ABS Chief Executive Thomas Choi said he has no regrets about purchasing the two Boeing-built satellites and booking, with Satmex — now owned by Eutelsat of Paris and renamed Eutelsat Americas — two SpaceX Falcon 9 v1.1 launches.
Choi said the launches were purchased for less than $60 million each. For the ABS-3A satellite, to be launched in early 2015, he said the cost of the satellite plus the cost of the launcher will enable ABS to deliver a 36-megahertz-equivalent transponder into orbit for $1.75 million.
Using electrical propulsion for a satellite like ABS-3A, which has 96 transponders when measured in 36-megahertz equivalents, produced a satellite that weighed around 50 percent of what it would weigh at launch with full chemical propellant.
As he did at the time of the Satmex/ABS contract with Boeing and Satmex, Choi said seeking innovative satellite and launcher configurations is an absolute must for the satellite industry if it expects to remain competitive against terrestrial technologies.
