PARIS — European governments will be asked in November to invest 200 million euros ($250 million) in partnership with Astrium Services in a third data-relay node in geostationary orbit for a global service relaying Earth observation satellite and unmanned aerial vehicle (UAV) data to civil and military users, according to European government and industry officials.

The program, called GlobeNet, would be the final piece of the European Space Agency’s (ESA) European Data Relay Service (EDRS) effort.

One dedicated satellite and one payload on a Eutelsat telecommunications satellite — both carrying laser optical data-relay terminals — are under construction. The 20-nation ESA, as part of the current EDRS program, has budgeted 270 million euros for the program so far, not including the third node in space.

The third payload would be a laser terminal hosted onboard a commercial telecommunications satellite, probably owned by a U.S. or Canadian satellite fleet operator, officials said.

The system is designed so that in addition to relaying data from low-orbiting and aerial platforms to ground users, it would permit optical links between the three geostationary-orbit satellites.

Intersatellite links in Ka-band are also being studied for UAVs and military applications.

Commercial satellite operators say the growing demand for UAVs that provide streaming video to military and civil customers — most think UAVs ultimately will be granted wide access to civilian airspace — will be a growth niche for them in the coming years.

Intelsat General of Washington, for example, already furnishes 950 megahertz of satellite bandwidth, the equivalent of 26 transponders, to about 70 UAV missions worldwide.

European officials want to make EDRS the de facto global standard for space-based data relay.

An industry official said ESA may elect to start slowly on GlobeNet to give Astrium time to line up a commercial satellite — in principle one built by its Astrium Satellites division — to host the data-relay terminal. This would also give financially stressed European governments a year or two to round up the financing.

Peter B. de Selding was the Paris bureau chief for SpaceNews.