The Era of Satellite Constellations Has Arrived
Matthew Greenwood posted on February 05, 2020 |
More people will have access to high-speed internet than ever before—but there are tradeoffs.

There are only about 2,200 satellites in orbit, but this is about to drastically change. Several companies are in the process of launching anywhere from hundreds to tens of thousands of satellites into orbit to bring high-speed internet connectivity to almost every corner of the planet.

Don’t We already Have Satellite Internet?

Current satellite internet is expensive and only features limited coverage to those dish-shaped receivers stuck to the sides of buildings and larger directional dishes. It is serviced by huge satellites parked in geostationary orbit at a speed that matches the Earth’s rotation almost 25,000 miles above the equator. Those satellites are large and powerful—one satellite can serve tens of thousands of customers. But they are also expensive, costing over $100 million each.

Information beamed down from these satellites can travel 47 percent faster than in fiber-optic cable. It’s also much easier for remote areas to access satellite-based service than installing miles and miles of cable.

But current satellite internet suffers from high latency. Radio waves traveling from these satellites can have latencies of 500 milliseconds or more, limiting the maximum data transfer rate and making it difficult to run latency-dependent applications.

A satellite can reduce that latency by orbiting closer to the ground, but that means giving up those coveted geostationary spots. The solution is a grid of smaller satellites in low earth orbit (LEO) less than 1,000 miles above ground.

Why a Whole Constellation?

A constellation consists of a connected network of satellites that orbit independently of the Earth’s rotation. The satellites are spaced apart precisely so that one satellite picks up the customer’s signal just as another one moves out of range.

Once deployed, not only will these constellations reduce lag, but they also will be able to bring high-speed internet to almost all of the world’s population.

The need for ground-based infrastructure will be reduced as well. While geostationary satellites rely on ground-based antennas, cables, a base station and networking equipment, constellation satellites integrate those components into the user terminal.

Several companies have ambitious plans to set up these constellations in the sky above us and broaden the reach of low-latency satellite internet to every corner of the globe. The three frontrunners are SpaceX, OneWeb and Amazon.

SpaceX’s Starlink

Starlink is by far the largest planned satellite constellation. The current plan boasts 11,925 satellites orbiting at 1,126km altitude and transmitting in the Ka-, Ku- and V- bands. The company has sent paperwork to the United Nations seeking approval for another 30,000 satellites. SpaceX has already started launching the satellites at a furious pace—about 60 every few weeks.  The company intends to provide limited service as early as 2020.

The Starlink constellation’s coverage.
The Starlink constellation’s coverage.

Each “flat panel” satellite weighs about 500 pounds. They will be rocketed to an altitude of 275 miles and then rely on their onboard ion thrusters to reach their destination altitude of 340 miles above the surface.

“We’re really talking about something which is, in the long term, like rebuilding the internet in space,” said Elon Musk, SpaceX CEO.

OneWeb Satellites

A joint venture between OneWeb and Airbus, the OneWeb Satellites constellation will feature 900 units. If customer demand warrants it, the constellation could grow to 2,000.

OneWeb’s satellites weigh less than 330 pounds and have fewer electrical connections than traditional larger communications satellites. They will orbit at 750 miles and function in the Ka- and Ku-bands.

The satellites were launched in early 2019. Regular launches of 30 satellites at a time are anticipated for 2020. Full commercial services are scheduled for 2021.

Amazon Kuiper Project

Making a late entry into the race is Amazon’s Kuiper Project. This constellation will have 3,200 satellites operating in the Ka-band. While satellite details are still being worked out, Amazon’s plan is for 784 satellites to orbit at an altitude of 367 miles, 1,296 at 379 miles and the remaining craft at 391 miles.

Other companies planning constellations are Telesat (292 satellites) and Iridium Next (66 satellites). China has its own plans for a global 5G constellation. Even the Pentagon is considering a military constellation.

Concerns

While the idea of global high-speed internet is laudable, it won’t be without its problems.

First, the number of objects in orbit could quintuple in the next decade, heightening the potential for collisions and making space exploration more dangerous.

These constellations will mean a five-fold increase in satellites.

Second, a sky full of satellites will impact ground-based astronomy. Starlink’s satellites are already interfering with astronomical research by creating glare from reflecting sunlight, as can be seen in the image below. SpaceX is testing a darkened satellite that would reduce that glare.

Third, the potential for radio frequency interference could increase. All these constellations will use microwave radio waves, so there is potential for ground-based receivers to get overloaded with electromagnetic radiation and raise the noise floor.

You can also add a geopolitical concern to this list. Many countries, most notably China and Russia, restrict internet access for their citizens. Constellations with inter-satellite links could bypass those restrictions. While in theory a worthy outcome, it could be fraught with political and economic consequences.

The U.N. estimates that there are close to 4 billion people unconnected and without internet access. Analysts and satellite companies anticipate that the demand for worldwide high-speed internet will be worth the cost. Some sources predict the market is valued at $1 trillion worldwide.

“There is no question that the entire world is entitled to be connected to the internet,” said Ruth Pritchard-Kelly, vice president of OneWeb. “It’s going to happen. And probably three or four of these systems are going to happen.”


Read more about satellite constellations at New OneWeb Factory Makes Two Satellites A Day.


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