Optical communication link for small satellites

Optical links are the future of satellite communications. Optical communication in space opens virtually unlimited capacities without regulations. By using lasers, satellite optical communication has a readily available frequency band and can transmit with higher power efficiency and with smaller and lighter terminals. Thus, it is expected to be a key technology to support the future satellite communication. For a given mass, power consumption and volume, laser communications can offer an increase in bandwidth over classical RF technology allowing for a variety of new options.

Laser links have been so far attempted by large satellites but the future presents a clear trend of satellite miniaturization (less than 10 kg) or even smaller down to 1kg satellites typically in the form of Cubesats. Despite their limited volume and power Cubesats can compete with the largest satellites.

Today many companies are planning to establish data communication network that will combine spaced-based optics and terrestrial fiber-optic network. The cost of high-rate optical cross links will be substantially lower than their microwave functional equivalent. With high-speed space optical cross link being a reality, the construction of an optical satellite broadband data network is now feasible. Various satellite constellations intended to provide global broadband coverage employ laser communication for inter-satellite links creating a space-based optical mesh network.

For ground station to keep very precise pointing during telescope motion and ambient temperature changes is essential. The optically inaccurately aligned ground station telescope concentrates only small fraction of the rather weak transmit lasers power onto the link terminal receiver, so communication will be weak or impossible.

Our  optical communication ground terminal terminal has innovative opto-mechanical design:

• Specially designed advanced common optical system in broad spectrum band and coaxial optical beams of transmit, receive and video channels working over a wide temperature range
• special design telescope mount with accurate pointing and tracking capability ensuring FSO link with fast moving flying platforms allowing narrow radiant laser beam working over a wide temperature range
• operational software for automatic data link control and data packets timing according data link real-time range changes
• transportable platform for FSO link data terminal employment and rapid installation. As LEO satellites only have a very reduced visibility from any ground station, more earth stations will be needed.

Our innovations in host spacecraft terminal will reduce the size, weight and cost of the flight modem

• special design telescope allowing narrow radiant laser beam working over a wide temperature range
  
• mount with accurate pointing and tracking capability for flying platforms ensuring FSO link from fast moving flying platform to ground segment