Bengaluru-based Astrogate Labs is working on an optical laser-based satellite communication technology that promises many advantages over traditional radio frequency transmission. Optical transmission can potentially offer higher bandwidth connections with lower data rates, while eliminating the need for high spectrum licensing costs.
“Modern satellites can generate over 100GB of data every day. If you use radio frequency transmission to download that data, you would hardly transfer 20 to 25 percent of the data in a day. With our optical transmission technology, you will get more than 20 times that bandwidth,” Nitish Singh, cofounder and CEO of Astrogate Labs told indianexpress.com in a video interaction.
Higher data bandwidth is just one of the advantages of laser-based optical transmission technology. According to Singh, a five-meter wide parabolic radio dish antenna can be replaced with a telescope-like ground receiver with an aperture between 30 and 40 centimeters when making the switch to optical satellite communication.
The European Space Agency’s European Data Relay Satellite System (ERDS) already uses this technology. ERDS consists of a series of satellites in geostationary orbits that are used to transmit information from and to non-geostationary satellites, spacecraft, other vehicles and fixed Earth Stations that cannot otherwise permanently transmit or receive data.
“Laser-based optical communication for satellites is an emerging technology. The technology has already been established and is being used on bigger satellites. What we are trying to do is make a more compact version of the system suitable for the smaller satellite segment,” explained Singh.
Nitish Singh, CEO and co-founder of Astrogate Labs, is pictured here. (Image credit: Astrogate Labs)
But unlike radio frequency antennas, which can produce radio beams that are many times the size of the Earth, laser beams are relatively narrow. This means the optical transmitter should be fitted on a precise pointing and tracking system that directs the laser beams in the direction of ground-based receivers.
Founded in 2017, Astrogate has been working on building the core technology required to make this possible. “We have already developed the space-to-ground solution, we have built the satellite communication hardware, and we have already qualified it. Now, we are looking at getting flight heritage for the technology,” added Singh. Flight heritage refers to when technology is tested in a commercially representative environment. Singh says Astrogate plans to have their technology in orbit by the end of 2024.
Apart from the challenges with pointing and stability, an optical communication system would also be susceptible to attenuation (loss in signal strength) due to the atmosphere, but this is also true for radio waves. However, unlike radio waves, cloud cover would prove catastrophic for optical communication. This is also one reason why the company is working to build these ground stations in drier regions of the world. “Currently, we have a collaboration in place to put them in Australia, and we are also looking at the Middle East,” Singh added.
Astrogate’s technology can also potentially be used for communication between different satellites that are part of the same “constellation.” Currently, the company is building a clientele that mainly includes organizations that want to launch Earth observation or experimental satellites for research. Any organization wanting to integrate Astrogate’s technology can buy the optical terminal and integrate it into their satellite, and then later subscribe to a ground communication plan to use the company’s receivers.
The company is also looking for applications of this technology outside of satellites and space purposes, and has already demonstrated its use in “ship-to-ship” communications.
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