The BBC's British radio antenna to arrive at space station says:

The new fridge-sized terminal will route video, voice and data to the ground through satellites that are actually higher in the sky than the ISS.

On occasions, these will continue to be the nodes in the American Tracking and Data Relay Satellite System (TDRSS), but the capacity is now there to go through a European alternative as well.

The European Data Relay System (EDRS) only has one satellite operating at the moment but will soon have a second.

This will afford the possibility of tens of minutes of dedicated, high-bandwidth connectivity for the Columbus lab on every 90-minute orbit of the Earth made by the station.

Astronauts are expected to use COLKa to video-call scientists who have experiments running on the ISS, and to make "welfare" connections with family and friends on Earth.

If I understand correctly, COLKa means the Ka-band communications channel for Columbus lab.

The linked article in the quote is titled Europe launches second EDRS space laser satellite and says:

The 3-tonne EDRS-C satellite also hosts a Ka-band radio frequency payload for the London-based Avanti telecommunications company.

Avanti calls the payload Hylas-3 and will be using it to deliver broadband and other data services to markets in Europe, the Middle East and Africa.

Question: So certainly some of the communications from the European antenna on the ISS's Columbus to EDRS will be via Ka-band, but I'd like to know if at least the hardware is now there for optical communication between the two as well.

A caution: the acronym EDRS can be short for European Data Relay System as well as for European Data Relay Satellite.


1 Answer 1


No, the COLKa (Columbus Ka-band antenna) provides only Ka-band communications.

This paper, while focused on the thermal design, provides the best overview of the system I have found: Columbus Ka-band Terminal thermal control - a compact design for varying conditions

It is made up of a steerable antenna, RF signal processing assemblies (LNAs, frequency converters, etc.), digital signal processing assemblies (digital modulators and digital demodulators), Command and Data Handling assemblies (PIAU), DC power conditioning assemblies (PDU), micro-wave filters, waveguides inter-connects, co-axial cable inter-connects, high speed digital cable inter-connects as well as of survival heaters and DC harnesses. With the Forward Service Link , low-rate data is relayed from the EDRS System Ground Segment to COLKa Terminal via the EDRS GEO satellite. The Return Service Link, also via the COLKa Terminal to the EDRS Ground segment via the EDRS GEO satellite, provides high-rate user data communications between the COLKa Terminal and the EDRS Ground Segment, such as video, sensor data, etc

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The eoPortal article is good as usual. It relies on the paper already cited as a primary source.


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