A stack of 60 SpaceX Starlink satellites hover above Earth in orbit.
To fund its Mars ambitions, SpaceX intends to transform the earth and cover the planet with an ubiquitous internet coverage broadcast by a close-knit network of thousands of satellites. CEO Elon Musk expects this "Starlink" service to ultimately generate $ 30 billion a year.
Construction is proceeding smoothly in space. SpaceX has already become the world's largest satellite operator, which manages and counts more than 500 satellites. That's a fraction of the thousands it wants to launch, but enough for the system to reach the Air Force cockpits and connect Musk to Twitter. The company plans to begin beta testing in North America this summer.
However, SpaceX still has a lot to do on site. Hardware has yet to be revealed to connect a customer's home to the satellites flying over us. The company will also need a network of ground stations that connect its satellites to the physical backbone of the Internet. The construction of these nodes is hardly rocket science: In fact, 26 are already planned for the USA. Without a crucial satellite upgrade, these stations will keep network coverage largely in the country.
"It's not a global service initially," said Tim Farrar, president of TMF Associates, a satellite and telecommunications research company, "although the satellites are flying all over the place."
Retroreflect global broadband
Efforts to down-stream data from the sky have usually been divided into two categories: the very close and the very distant. For example, Google's parent company, Alphabet, uses internet balloons about 19 km above the ground in Kenya, and Facebook has solar-powered drones in view. These near-surface approaches are fast, but each floating antenna has a limited geographic footprint.
In contrast, companies like the Canadian communications company Telesat have long operated a handful of satellites in high orbits more than 20,000 miles above the earth's surface, where every machine can reach a large part of the planet. These systems offer global coverage, but helical connections, with orbital signals lasting more than half a second. "It doesn't sound like a big deal, but a typical website may have 100 tours," said Erwin Hudson, Vice President of Telesat. "It adds up."
With Starlink, SpaceX joins a number of companies, including Telesat, all trying to deliver the best of both worlds: "constellations" of satellites that are close enough to communicate with the ground in ten milliseconds, but far enough to cover the planet with a reasonable number of satellites. However, to complete the service, SpaceX requires two additional ground-based infrastructures.
Starlink's biggest hurdle on land
According to Musk, Starlink's biggest terrestrial hurdle is the antenna that users can use to go online – the Internet analogue of the TV parabolic dish. Starlink's low-flying satellites zoom across the sky in about five minutes, and the antennas have to keep up. SpaceX's design must balance technological sophistication with affordability in the mass market.
The company plans to use "phased array antennas" that can electronically steer the focus of the machine instead of physically turning it around. The technology mechanically simplifies the device, but has a high price. Farrar estimates that the device could cost more than $ 1,000, even though Musk is aiming for less than $ 300. In March, the FCC approved SpaceX to distribute one million antennas, and SpaceX board members recently tested the devices (which are reported to be similar to "UFOs on a Stick"), but the company has not yet announced the retail version.
Each satellite service also requires a network of ground stations to use the existing fiber optic infrastructure. These are the points at which the space network merges with the World Wide Web. "What goes up has to come down," said Hudson.
SpaceX is also preparing these "gateway" stations. The company has registered 26 locations with the FCC, each of which can accommodate eight antennas. Some are owned by SpaceX, while others are owned by telecommunications companies such as Level Three Communications, which are believed to be able to provide high-speed connections. A handful of mushroom-shaped domes have recently appeared on some properties – radar-transparent weather protection for antennas.
Why "networking" is the key concept
These gateways are just the beginning. For maximum performance, Starlink may need thousands of gateway antennas (roughly one per satellite) spread across hundreds of locations worldwide, according to MITI graduate, Íñigo del Portillo Barrios, who recently studied the structure of the Starlink and Telesat constellations analyzed.
He says Starlink relies heavily on these stations because the current range of satellites lacks an originally planned function that enables the machines to communicate with their neighbors via lasers. This "networking" capability would allow Starlink to relay a signal to anyone under a satellite – even to users in the air, on remote islands or in conflict areas. Without it, however, a satellite must be able to connect a user directly to a gateway antenna, limiting coverage to approximately 500 miles from each ground station, Farrar estimates.
"They'll have big holes in the middle of the ocean and some deserts," said Farrar. "You have to go to a country’s regulatory agency and say," Please let us in, please let us build the gates in your country. "
This is hardly a show stopper to reach most rural areas (currently planned stations will cover most of the United States and Mexico). Traditional satellite Internet customers such as the military, who want access through central Iraq, for example, or airlines and shipping companies looking for connectivity in the Atlantic and Pacific, may prefer to wait for a truly global service.
SpaceX did not respond to a request for comment on its gateway or networking plans, but Hudson says that although Telesat has 50 years of satellite experience and plans to launch networkable satellites by 2022, the choreography of ground operations is still one of its responsibilities will be big challenges.
"We are building earth stations on every continent except possibly Antarctica," he said. "You have to ship things everywhere. You have to build, maintain and upgrade them."
The addition of networking will ultimately help SpaceX reduce the geographic variation in Starlink coverage, and the company plans to experiment with interconnected satellites later this year, President Gwynne Shotwell said.
However, the upgrade will not be easy and the second generation network will not be operational in the near future. First, SpaceX needs to revise its satellite design to integrate a more powerful power supply, fine-tuned lasers and other hardware. Then the entire swarm must be rebuilt and restarted.
The company can do it at some point, said Farrar, but first Starlink has to prove itself with the satellites in the sky and the gateway stations it can build on the ground.