Mega constellations, facilitated by laser, rocket, and antenna innovations will change the economics of satellite-provided broadband.
Inter-Satellite Link (ISL). This allows satellites in a constellation to link to one another using lasers. Since 2001 governments (NASA, ESA, Japan, Germany), and companies (Google, Facebook) have been testing space communications. The most recent batch of Starlink has ISL capability, and all future large constellations are expected to add it also. ISL reduces backhaul costs, improves satellite control, and reduces network latency. In simple terms, ISL allows traffic to beam to satellites nearer data centers containing netflix, youtube, etc.
Reusable Rockets. The Atlas V costs $165M per launch. Falcon 9 costs $62M new and $30M if reused. So far, SpaceX delivers 60 rockets per Falcon 9 launch.
Phased array antenna. The cost for a motorized ground dish to follow satellites is prohibitively expensive for residential broadband. A phased-array antenna uses an array of internal antennas elements. In the case of Starlink, these antennas cost $2500 and are subsidized and recouped by an initial $500 antenna price and $99 per month unlimited usage fee.
Miniaturization and mega-constellations. Modern LEO satellites are roughly the size of a table and weigh ~260 kg. Failed units burn up as they reenter Earth’s atmosphere leaving no orbital debris or satellite parts hitting the ground. Starlink satellite service life is 5 years, after which time they run out of propellant and surfer radiation damage. This protects Earth from Kessler syndrome––a phenomenon when failed equipment in orbit around Earth reaches a point where it creates more and more space debris. Miniaturization reduces cost and launch complexity, enabling mega constellations, but short satellite service life will place new economic pressure on constellations. Mega LEO constellations are an absolute prerequisite for LEO-powered internet broadband.
Geostationary constellations cannot provide broadband internet because of their orbit 35,000 kilometers from earth. Each one-way takes 116 milliseconds (35.000,000 m / 299 792 458 m/s = 116 ms). This route is doubled and more as the signal returns from space, then terrestrial and subsea cables to the most proximal data center. This trip length causes an average minimum 600 ms latency––too latent for zoom etc.
LEO constellations are 60x closer and can offer 25 ms latency. Starlink is currently 550 km.
The largest LEO satellite constellations are below, sorted by launched satellites.
Elon loves strategic moats, and Starlink has a massive one. Because of atmospheric drag, LEO satellites lifespan is 1/3 that of GEO satellites. This is a moat for Starlink. SpaceX can inexpensively subsidize Starlink launches by filling unused cargo capacity with Starlink satellites. They are modular. No other constellation has this competitive advantage, and the moat widens as constellations grow in capacity, and become more expensive to maintain.
There are still too many places and devices where broadband access is unreliable or doesn’t exist for everyday use and emergencies. LEO satellite breakthroughs will change that. I’ll explore this in a five-part series.
In the 1980s and 1990s ground cables powered BBS’s and university WANs through modems. In the 2000s and 2010s upgraded ground and subsea cables powered WiFi Internet to ~70% of the US. The 2020s and 2030s could see satellite-delivered WiFi Internet to the remaining 30% of the US and even more in ROW. This future possibility is bold given previous bankruptcies in the satellite industry, and conservative given recent successes by Starlink.
On the moon in 1971, Commander David Scott dropped a hammer and a falcon feather to validate Galileo’s theory that without air resistance, objects fall at the same rate due to gravity regardless of mass. Given the negligible lunar atmosphere, there was no drag on the feather, both experienced the same acceleration, and both hit the ground at the same time. NASA did this because they wanted a memorable popular science experiment to do on the Moon, for kids. Very cool to watch.
Our experience on earth makes us think that the tides are causing by water following the moon and sun. It turns out the water isn’t chasing the moon and sun. The water stays in the same place as the earth rotates inside the two bulges of water. More on this in the video and on wiki.
We’re fortunate to live in a time when we have two new launch rockets intended to enable crewed launches to Mars.
The two rockets on the left have flown already. The Falcon Heavy flew in 2018 and is currently 32M miles from home traveling at 58K mph. The Saturn V launched the Apollo Missions between 1967-1973.
The two rockets on the right haven’t flown yet. Boeing’s Space Launch System is more expensive and also is not reusable, so it has larger expected price (green bar graph) and $ per kilogram (blue bar graph) characteristics.