Commercial laser comm edges closer to reality
“If you build it, they will come” is the motto of BridgeSat, a company building a network of laser-equipped ground stations for high-speed communications with satellites.
“Optical communications is technically possible to do,” Barry Matsumori, BridgeSat’s chief executive, told SpaceNews. “Why BridgeSat exists is to help all of the space terminal providers get started because they have to have a place on Earth to go. Without a ground network, there is nothing for these space terminals to talk to.”
Builders of satellite laser-comm technology have described a “chicken and the egg” impasse to true adoption: one needs both an optical ground segment and in-space optical terminals for the system to work.
BridgeSat aims to build 10 ground stations around the world by the end of 2019, creating a network of sites that can handle substantially larger amounts of data than today’s radio-frequency stations to connect satellites back to the Earth. The first station is under construction at the Sierra Remote Observatory near Fresno, California, with operations scheduled for July, Matsumori said.
Projects like NASA’s laser-terminal-equipped Lunar Atmosphere and Dust Environment Explorer spacecraft and the European Space Agency’s SpaceDataHighway program have demonstrated the technology, which requires very precise pointing across thousands of kilometers, can work. Tesat-Spacecom, manufacturer of the optical terminals on the five-satellite SpaceDataHighway network, is now ready to commercialize the payload technology for other spacecraft.
“We see a significant change happening at the moment,” said Herwig Zech, Tesat-Spacecom’s communications systems product manager. “One or two years ago, we were talking to future missions and future technology people. Today we are talking to real mission planners about actual projects that are foreseen and in the realization phase. Optical communications is no longer just a scientific research topic; industry-wide it is a reality.”
Zech said Tesat-Spacecom of Backnang, Germany, is nearly finished developing two commercial laser terminals, one for cubesats that can beam 10 gigabits per second between spacecraft at distances up to 6,000 kilometers, and another for 10 Gbps space-to-ground communications. Target customers for these systems are low-Earth-orbit constellations, he said.
Matsumori, who took the helm at BridgeSat after previous careers at Qualcomm, Virgin Orbit and SpaceX, said BridgeSat is working with Tesat-Spacecom and Thales Alenia Space to create optical terminals that will work with the BridgeSat network. Terminals from other manufacturers will also work with BridgeSat’s ground network, he said.
“My primary business is a global network of ground stations,” Matsumori explained. “Think of it as Verizon. Verizon makes money by phones using their network. The phone itself is a means to getting the network usage. BridgeSat is the same.”
BridgeSat’s target customers are remote-sensing operators whose satellites collect large volumes of imagery and need to quickly dump that data to clear memory for new observations. Iceye, the Finnish startup that launched a 70-kilogram synthetic aperture radar satellite in January, agreed in May to use BridgeSat terminals and the company’s ground network.
Like the transition from copper wires to fiber optic cables, ground stations that use optical terminals can support substantially higher throughputs. That means remote-sensing satellites can beam down more pictures, and telecom satellites can devote more in-space radiofrequency resources to revenue generation, Matsumori said. A single optical ground station “can download terabits easily” during the minutes when a satellite passes overhead, he said.
Bill Ostrove, an analyst at Forecast International, described laser-comm as having a lot of potential not only for greater throughput, but because it doesn’t require coveted radio-frequency spectrum.
“As radio waves become more crowded and more data is being demanded of satellites, it’s a way of increasing bandwidth and avoiding radio-frequency crowding issues,” he said.
The catch is optical links are weather sensitive — cloud cover blocks the beams, disabling communications. Matsumori emphasized site diversity — having stations spread out geographically in sunny regions — so that if one station is blocked, another can take its place.
To streamline regulatory landing rights approvals, Matsumori said BridgeSat is working with local partners to co-locate optical ground stations with established radio-frequency sites.
“With Swedish Space Corporation we are going to many of their sites, and they will help us with landing right coordination,” he said. “Others that have these sites will do the same.”
Neither BridgeSat nor Tesat-Spacecom are alone in developing optical communications systems. Boston startup Analytical Space, which declined to comment for this article, is designing a network of laser relay satellites, with radiofrequency cross links and optical downlinks. Ball Aerospace and Honeywell teamed up in April to build laser terminals for communications between ground stations, satellites and aircraft.
Large telecom constellation programs from LeoSat, Telesat, and SpaceX, all anticipate using optical intersatellite links. Airbus’ four Pleiades Neo satellites, scheduled for launch in 2020 on two Vega C rockets, will feature Tesat-Spacecom optical links to patch into Europe’s SpaceDataHighway.
Tesat-Spacecom’s Zech said the company is building up manufacturing product lines to create terminals for constellations and other programs.
“We were in this chicken and the egg situation three to five years ago … now I think the confidence and the trust in the technology is higher,” Zech said. “That’s the reason why people are looking really seriously at optical communications.”