Plasma thrusters shrink satellites

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This Aviation Week article really shows how much mass can be saved using electric plasma thrusters instead of chemical propulsion.

Plasma thrusters do this by having a very high Isp, or specific impulse - a measure of efficiency. Chemical thrusters have an Isp of perhaps 350, higher = better, while plasma drives can reach into the thousands.

Quite literally, they can bring a satellites mass down from needing a Falcon Heavy, Ariane 5, Proton or Zenit launcher to a Falcon 9. It should also allow 6,000+ kg satellites to have much greater capabilities.

http://m.aviationweek.com/technology/eutelsat-ses-add-plasma-fueled-spacecraft-fleets

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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.

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NASA video

http://youtu.be/j71evfD8TRY

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A good example of this is the new Boeing 702SP (SP= small platform) GTO commsat. It does all the bands of the full size Boeing 702, and has a 15 year lifetime, but it was designed to be dual-manifested on smaller launchers.

The first dual launch by Falcon 9 is for Asia Communications Services and SatMex, which is NET early 2015. Another dual F9 launch for them comes later.

http://m.aviationweek.com/technology/eutelsat-ses-add-plasma-fueled-spacecraft-fleets

fleets

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While the (Boeing) 702SPs lengthy transit time to orbit creates a lag between launch and the satellites 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 702SPs 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.

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