# How Satellite Internet Works

> In October 2026 Ukraine's military found its Starlink and Starshield connections slowed for more than a week; Elon Musk said SpaceX had throttled the service, accusing Ukraine of breaking its terms, which Ukrainian officials denied. This film explains the technology behind the row: why radio needs a relay above the curve of the Earth, Arthur C. Clarke's 1945 idea of satellites that hang still, Telstar in 1962, geostationary satellites and why they add half a second of delay, low Earth orbit constellations from Iridium in 1998 to Starlink's more than 10,000 satellites, flat phased-array dishes that steer their beams with timing alone, why heavy rain weakens the signal, ground stations and laser links between satellites, how the operator controls where and how the service works, and the costs of a crowded sky for astronomy and space debris.

Interactive film: https://www.planetpast.com/stories/how-satellite-internet-works/  
Publisher: PlanetPast (https://www.planetpast.com/) · d => T('readPublished', l, { d: dateIn(d, l) }) 2026-10-27 · Technology, Space, Physics

## Prologue

### A network in the sky
*Technology · Space · Physics*

Who holds the switch, and how it all works.

In October 2026, Ukraine's military found its satellite internet links restricted for more than a week. Commanders reported disrupted drone missions. On 24 October, Elon Musk said his company SpaceX had throttled its Starlink service there, accusing Ukraine's military of breaking its terms. Ukrainian officials denied it, and said speeds were back that day. How can a company change a country's connection from far away? Because satellite internet is one network, run end to end by whoever operates it. Let's see how it works.

- **>1 week**: Starlink and its military version, Starshield, restricted
- **24 Oct**: restored, according to Ukraine

- Musk: Ukraine broke the terms; the “loophole” was closed
- Ukrainian officials: no terms were broken
- Trump administration: no US government role

- Why radio needs a relay in the sky
- High orbits, low orbits and delay
- Dishes that steer without moving
- Who controls the network

Prologue

#### A slowdown with two accounts

CBS News: Ukraine’s access to Starlink and its military version, Starshield, was restricted for more than a week; commanders reported lost drones and disrupted missions, and speeds were restored overnight into Saturday 24 October. NPR: Musk wrote on 24 October that Ukraine’s military “violated Starlink terms of service and used it for offensive drone strikes to kill people” and that the “loophole was closed last week”; on 14 October he had written that Starshield is owned and controlled by the US government and that “any limits on speed or usage are decided by the US military and ultimately POTUS”. The Washington Post: current and former Ukrainian officials denied violating the terms; a presidential adviser noted that the service does not work over Russian territory.

Trump administration officials denied any US government role; on 25 October President Zelenskyy said Ukrainian officials believed Washington was behind it (NPR). This film does not try to settle who decided what; it explains the system that made a remote slowdown possible.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [CBS News (24 Oct 2026): Ukraine says Starlink speeds restored as Elon Musk admits SpaceX throttled service](https://www.cbsnews.com/news/ukraine-starlink-drone-spacex-musk-speed-restriction/); [NPR via KPBS (24 Oct 2026): Musk says SpaceX did restrict Starlink, as Ukraine says the tech has been restored](https://www.kpbs.org/news/international/2026/10/24/musk-says-spacex-did-restrict-starlink-as-ukraine-says-the-tech-has-been-restored); [Washington Post via The Spokesman-Review (25 Oct 2026): Elon Musk says SpaceX was behind restrictions to Ukraine’s Starlink access](https://www.spokesman.com/stories/2026/oct/25/elon-musk-says-spacex-was-behind-restrictions-to-u/); [Wikipedia: Starlink in the Russo-Ukrainian war (activation in 2022, terminals, geofencing, Starshield, whitelisting in 2026)](https://en.wikipedia.org/wiki/Starlink_in_the_Russo-Ukrainian_war)

## Chapter I · A relay in the sky

### A relay in the sky
*Chapter I*

Radio goes straight. The Earth does not.

Radio waves at the frequencies used for television and data travel in straight lines. The Earth curves away beneath them, so a tower can only reach as far as its horizon. To cross an ocean, you need a relay high above it. In 1945, the writer Arthur C. Clarke described one: satellites in an orbit where they would seem to hang still in the sky. Far above the equator, there is a height where one orbit takes exactly as long as one turn of the Earth.

$$d \approx \sqrt{2Rh}$$
- $R$: Earth’s radius, 6,371 km
- $h$: height of the antenna

A 100 m tower: about 36 km to the horizon. The atmosphere bends radio a little further.

![Clarke’s first outline appeared as a letter in Wireless World in February 1945. AI-generated illustration.](https://assets.planetpast.com/a/92/92e1decf02e8363a.jpg)

- **≈ 35,786 km**: above the equator
- **23 h 56 min**: one orbit = one turn of the Earth (sidereal day)

Chapter I · A relay in the sky

#### Beyond the horizon

Wikipedia, line-of-sight propagation: frequencies above about 30 MHz (VHF and higher) travel in straight lines and are limited by the radio horizon, where direct rays from an antenna touch the curve of the Earth; normal atmospheric refraction extends the range by about 15%. The geometric distance to the horizon from height h is about √(2Rh), which gives roughly 36 km for a 100-metre antenna.

Lakdiva.org: Clarke’s letter “Peacetime Uses for V2” appeared in Wireless World in February 1945 (page 58); the orbit it implies is circular and equatorial, about 42,164 km from the Earth’s centre (about 35,786 km above sea level), with a period of one sidereal day, 23 h 56 min. ESA gives 35,786 km.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [Wikipedia: line-of-sight propagation (VHF and above; radio horizon)](https://en.wikipedia.org/wiki/Line-of-sight_propagation); [Lakdiva.org: Arthur C. Clarke’s 1945 proposal in Wireless World (letter “Peacetime Uses for V2”, February 1945) and the geostationary orbit](https://lakdiva.org.lk/clarke/1945ww/); [ESA: types of orbits (GEO 35,786 km; LEO 180–2,000 km, ~90 min; constellations)](https://www.esa.int/Our_Activities/Launchers/Types_of_orbits)

### 

The first relay satellites flew much lower. Telstar 1, built by Bell Labs and launched in July 1962, carried the first live television across the Atlantic. But its orbit was low and stretched, so it raced across the sky. Each pass over the Atlantic gave only about eighteen minutes; then the picture was gone until it came round again. On the ground, the receiving antenna in Maine was a horn seven storeys high. Telstar also carried telephone calls and data, and AT&T paid for it, making it the first privately financed satellite.

![A sphere 34.5 inches across, about 88 cm, weighing 171 pounds, covered in solar cells. AI-generated illustration.](https://assets.planetpast.com/a/f5/f561cacbdd8fe572.jpg)

- **952 km**: lowest point
- **5,933 km**: highest point
- **~18 min**: usable per pass over the Atlantic

![The real horn weighed 340 tons and sat inside a protective dome. AI-generated illustration.](https://assets.planetpast.com/a/12/127872308d999cca.jpg)

- **AT&T**: the first privately financed satellite (NASA)

Chapter I · A relay in the sky

#### The first transatlantic picture

Wikipedia, Telstar 1: launched on 10 July 1962 from Cape Canaveral; first live transatlantic television on 23 July 1962; orbit 952 × 5,933 km; built by Bell Labs and operated by AT&T and NASA; it worked until radiation from the Starfish Prime nuclear test damaged it, and its transmitter failed on 21 February 1963. NASA: it was available for only about 18 minutes at a time as its orbit passed over the Atlantic; the Andover, Maine, horn antenna was seven stories high and weighed 340 tons; AT&T paid for it, making it the first privately financed satellite.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [Wikipedia: Telstar 1 (launch 10 July 1962; first live transatlantic TV 23 July 1962; orbit 952 × 5,933 km)](https://en.wikipedia.org/wiki/Telstar_1); [NASA: Telstar opened era of global satellite television](https://www.nasa.gov/content/telstar-opened-era-of-global-satellite-television)

## Chapter II · Parked overhead

### Parked overhead
*Chapter II*

High enough to stand still.

Clarke's orbit solved that. A geostationary satellite, about 35,786 kilometres above the equator, appears fixed in the sky, so a dish can be pointed at it once and never moved again. From that height, three satellites spaced evenly around the equator can cover almost the whole world. Thailand's first satellite, Thaicom 1, was launched in December 1993 into a slot like this. Gravity is weaker that far out, so orbits are slower: about three kilometres per second, just enough to keep pace with the turning Earth below.

![Fixed dishes like this one are aimed at a single geostationary satellite. AI-generated illustration.](https://assets.planetpast.com/a/ad/ad30b584656cf776.jpg)

- **≈ 3 km/s**: orbital speed
- **3**: satellites for near-global coverage

- 1945: Clarke describes the orbit
- 1962: Telstar: low, moving, minutes per pass
- 1993: Thaicom 1, Thailand’s first satellite

- Low orbit, ~400 km: ≈ 7.8
- Geostationary, 35,786 km: ≈ 3

Chapter II · Parked overhead

#### The geostationary belt

ESA: a geostationary satellite circles at about 35,786 km above the equator at about 3 km/s, taking 23 hours 56 minutes and 4 seconds per orbit, the same as one turn of the Earth, so it appears fixed over one spot; three evenly spaced satellites can provide near-global coverage. Wikipedia, Thaicom: Thaicom 1 was launched on 18 December 1993; it was positioned at 78.5° East.

In the scene the orbit height is to scale with the globe; the satellites and their footprints are schematic.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [ESA: types of orbits (GEO 35,786 km; LEO 180–2,000 km, ~90 min; constellations)](https://www.esa.int/Our_Activities/Launchers/Types_of_orbits); [Wikipedia: Thaicom (Thaicom 1 launched 18 December 1993)](https://en.wikipedia.org/wiki/Thaicom); [Lakdiva.org: Arthur C. Clarke’s 1945 proposal in Wireless World (letter “Peacetime Uses for V2”, February 1945) and the geostationary orbit](https://lakdiva.org.lk/clarke/1945ww/)

### 

But height has a price. Radio travels at the speed of light, about 300,000 kilometres per second, and that is a long way to go. Up to the satellite and back down takes about a quarter of a second. A question and its answer need that trip twice: about half a second, before any other delay is added. In 2025 measurements by Ookla, the main geostationary internet services had a median delay of about 680 milliseconds. Fine for television; painful for video calls, games, or steering a drone. The rest of the measured delay comes from the journey on to distant servers and back, and from processing along the way.

$$t = \frac{2h}{c} = \frac{2 \times 35{,}786\ \text{km}}{299{,}792\ \text{km/s}} \approx 0.24\ \text{s}$$
- $h$: height of the satellite
- $c$: speed of light

Directly overhead; from the edge of the coverage area the path is longer.

- **≈ 0.24 s**: one hop, up and down
- **≈ 0.48 s**: a request and its reply

- Viasat (GEO): 684 ms
- HughesNet (GEO): 683 ms

- The trip on to distant servers
- Processing in dish, satellite and gateway
- A satellite away from overhead: a longer slant path

Chapter II · Parked overhead

#### Half a second, at the speed of light

The arithmetic: light covers 299,792 km per second, so one hop up to a geostationary satellite and back down (2 × 35,786 km) takes at least about 0.24 s, and a request plus its reply about 0.48 s. NewSpace Economy, citing Ookla’s 2025 figures: median latency was 683 ms for HughesNet (Q1 2025) and 684 ms for Viasat, against 45 ms for Starlink.

Try it: send a ping through a geostationary satellite, then through a low one, and compare the clock. The pulse speed is slowed down so you can see it; the times shown are the real light-travel times.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [ESA: types of orbits (GEO 35,786 km; LEO 180–2,000 km, ~90 min; constellations)](https://www.esa.int/Our_Activities/Launchers/Types_of_orbits); [NewSpace Economy (15 Jul 2025): satellite internet in 2025, HughesNet and Viasat struggle to keep up with Starlink (Ookla median latency figures)](https://newspaceeconomy.ca/2025/07/15/satellite-internet-in-2025-hughesnet-and-viasat-struggle-to-keep-up-with-starlink/)

## Chapter III · Fast and low

### Fast and low
*Chapter III*

Close enough to be quick, too fast to stay.

The alternative is to fly low. Low Earth orbit runs from about 180 to 2,000 kilometres up. That close, light's round trip takes only milliseconds. The catch: a low satellite circles the planet in about ninety minutes, and is above any one spot for only a few minutes. To always have one in view, you need many. That is a constellation. Try changing how many there are. Iridium tried it first, for phones: 66 satellites at about 780 kilometres, passing calls from one to the next. Service began in November 1998, but the original company went bankrupt.

- **180–2,000 km**: altitude
- **≈ 90 min**: per orbit, at about 7.8 km/s

$$\frac{24\ \text{h}}{90\ \text{min}} = 16\ \text{orbits}$$

The International Space Station, in a similar orbit, circles Earth about 16 times a day.

![Iridium’s satellites link to their neighbours, so a call can travel through space before coming down. AI-generated illustration.](https://assets.planetpast.com/a/13/13c3981d32234b7a.jpg)

Chapter III · Fast and low

#### A swarm instead of a fixture

ESA: low Earth orbit lies between about 180 km and 2,000 km; satellites there take about 90 minutes per orbit at about 7.8 km/s, and communications satellites in LEO often work as constellations that together give continuous coverage. Britannica: a LEO satellite is over any one spot for only a few minutes, so many satellites are needed for continuous service; Iridium, deployed in 1998, was the only LEO communications constellation actually built in the 1990s.

Wikipedia, Iridium: 66 active satellites at about 781 km, with spares; commercial service from 1 November 1998; each satellite links by Ka-band to up to four neighbours; the original company went bankrupt. Try it: switch between 12 and 66 satellites and watch how much of the ground is covered. Coverage circles are schematic.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [ESA: types of orbits (GEO 35,786 km; LEO 180–2,000 km, ~90 min; constellations)](https://www.esa.int/Our_Activities/Launchers/Types_of_orbits); [Britannica: Starlink (LEO below ~1,600 km; many satellites needed; Iridium 1998; first 60 satellites in May 2019; collision avoidance)](https://www.britannica.com/topic/Starlink); [Wikipedia: Iridium satellite constellation (66 active satellites at ~781 km; service from 1 November 1998; inter-satellite links)](https://en.wikipedia.org/wiki/Iridium_satellite_constellation)

### 

Cheaper rockets changed the sums. SpaceX launched its first sixty Starlink satellites in May 2019. Most now fly at around 550 kilometres. By March 2026, more than ten thousand were in orbit at the same time. As one sinks toward the horizon, there is always another rising to take over. And because they are so close, Ookla measured Starlink's median delay in 2025 at about 45 milliseconds: fifteen times less than the old high satellites. By mid-2024, according to Britannica, Starlink already made up more than half of all the active satellites in orbit.

- **60**: first operational batch, May 2019
- **~550 km**: main shell, 53° inclination

- **>10,000**: in orbit at once, March 2026
- **>50%**: of all active satellites were Starlink by June 2024 (Britannica)

- Viasat (GEO): 684 ms
- HughesNet (GEO): 683 ms
- Starlink (LEO): 45 ms

- 2018: Two test satellites
- 2019: First 60 operational
- 2024: More than 6,000
- 2026: More than 10,000 at once

Chapter III · Fast and low

#### Thousands of satellites

Britannica: SpaceX launched its first batch of 60 operational Starlink satellites in May 2019, after two test satellites in February 2018; by June 2024 there were more than 6,000, over half of all active satellites. eoPortal: most Starlink satellites fly at about 559 km, the main shell at roughly 540–570 km and 53° inclination; more than 10,000 were reported in orbit at once in March 2026. NewSpace Economy, citing Ookla: Starlink’s median latency in 2025 was 45 ms.

The scene draws a few hundred satellites, not ten thousand, and makes them far larger than real.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [Britannica: Starlink (LEO below ~1,600 km; many satellites needed; Iridium 1998; first 60 satellites in May 2019; collision avoidance)](https://www.britannica.com/topic/Starlink); [eoPortal (ESA): Starlink satellite constellation (altitudes, more than 10,000 in orbit in March 2026, Ku/Ka bands, phased-array terminals, laser links, krypton thrusters, deorbiting)](https://directory.eoportal.org/satellite-missions/starlink); [NewSpace Economy (15 Jul 2025): satellite internet in 2025, HughesNet and Viasat struggle to keep up with Starlink (Ookla median latency figures)](https://newspaceeconomy.ca/2025/07/15/satellite-internet-in-2025-hughesnet-and-viasat-struggle-to-keep-up-with-starlink/)

## Chapter IV · A crowded sky

### A crowded sky
*Chapter IV*

What thousands of satellites cost.

Thousands of satellites also bring costs. Astronomers find bright streaks across their long exposures, and the satellites' radio emissions can drown out faint signals from space. Collisions are a risk too. SpaceX reported that its satellites swerved to avoid other objects more than 25,000 times in just six months, from December 2022 to May 2023. At the end of their lives, low satellites are steered down to burn up in the atmosphere. The open question is whether launches will keep outpacing what comes down. The International Astronomical Union warns that the tens of thousands of satellites still planned would make these problems hard to fix.

![The IAU says the effect is strongest just after launch, when satellites still travel in tight groups. AI-generated illustration.](https://assets.planetpast.com/a/dd/ddf5cfb6260ce98e.jpg)

- **>25,000**: Starlink avoidance manoeuvres, Dec 2022 – May 2023
- **×2**: the previous six months

![Starlink satellites carry krypton-fuelled thrusters that are also used to deorbit them. AI-generated illustration.](https://assets.planetpast.com/a/9d/9dfb63e16e7730a4.jpg)

> “The brightness is a main concern for our astronomical field.” (IAU, on satellite constellations)

Chapter IV · A crowded sky

#### The price of a megaconstellation

International Astronomical Union: reflective satellite surfaces appear as moving dots and leave bright trails across long exposures, an effect strongest just after launch; combined radio emissions can threaten radio astronomy; and tens of thousands of planned satellites would make the problem hard to mitigate. Britannica: SpaceX reported more than 25,000 avoidance manoeuvres between December 2022 and May 2023, double the previous six months, and in 2021 China told the UN its Tianhe module had twice manoeuvred to avoid Starlink satellites.

eoPortal: Starlink satellites use krypton Hall-effect thrusters for orbit raising, station keeping and deorbiting, and are designed to burn up on re-entry. Try it: compare the number of Starlink satellites drawn for 2019 (60), 2024 (more than 6,000) and 2026 (more than 10,000); one dot stands for about ten satellites.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [International Astronomical Union: satellite constellations (brightness, streaks, radio interference)](https://iauarchive.eso.org/public/themes/satellite-constellations/); [Britannica: Starlink (LEO below ~1,600 km; many satellites needed; Iridium 1998; first 60 satellites in May 2019; collision avoidance)](https://www.britannica.com/topic/Starlink); [eoPortal (ESA): Starlink satellite constellation (altitudes, more than 10,000 in orbit in March 2026, Ku/Ka bands, phased-array terminals, laser links, krypton thrusters, deorbiting)](https://directory.eoportal.org/satellite-missions/starlink)

## Chapter V · The dish that steers

### The dish that steers
*Chapter V*

Pointing a beam with timing alone.

A satellite that crosses the sky in minutes is hard to follow with a dish that moves. So the user terminals are flat, and do not swing round to follow each satellite. Inside is a phased array: many small antennas side by side. If they all send at the same moment, their waves add up straight ahead. Delay each one a tiny bit more than its neighbour, and the waves line up at an angle instead. The beam tilts, with no moving parts. Try steering it. With elements spaced half a wavelength apart, the beam can in theory swing all the way down to the horizon.

![Each square patch is one antenna element; together they act as one large, steerable antenna. AI-generated illustration.](https://assets.planetpast.com/a/d7/d766c0f3973840a4.jpg)

- **Same moment**: all elements send together: beam points straight up

$$\Delta\varphi = \frac{2\pi\, d \sin\theta}{\lambda}$$
- $\Delta\varphi$: shift between neighbouring elements
- $d$: spacing of the elements
- $\theta$: beam angle
- $\lambda$: wavelength

With elements half a wavelength apart, a 180° shift steers the beam 90° in theory.

- Follows a satellite across the sky
- Switches to the next one in an instant
- No motors needed to track

Chapter V · The dish that steers

#### Steering by timing

Analog Devices, Analog Dialogue: a phased array steers its beam by delaying or phase-shifting the signal of each element and summing them; when the shifts line up the signals from a given direction, they add and the array responds strongly there. The phase shift between neighbouring elements is Δφ = 2π·d·sinθ/λ; with half-wavelength spacing it becomes π·sinθ. eoPortal: Starlink user links use phased-array Ku/Ka-band antennas.

Try it: steer the beam left, straight up or right. The wave pattern is computed from sixteen elements in a line, a simplified slice of a real flat array.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [Analog Devices, Analog Dialogue: phased array antenna patterns, part 1 (beam steering by phase shift)](https://www.analog.com/en/resources/analog-dialogue/articles/phased-array-antenna-patterns-part1.html); [eoPortal (ESA): Starlink satellite constellation (altitudes, more than 10,000 in orbit in March 2026, Ku/Ka bands, phased-array terminals, laser links, krypton thrusters, deorbiting)](https://directory.eoportal.org/satellite-missions/starlink)

### 

The links use microwaves, in frequency bands called Ku and Ka. High frequencies carry lots of data, but they have a weakness. Raindrops absorb them. The shorter the wavelength gets, closer to the size of a raindrop, the more energy heavy rain soaks up. In a tropical downpour, the signal can fade. Engineers build in a margin of extra power for it, which is why heavy rain is a bigger problem in places like Thailand than in drier lands. Snow and ice cause no comparable loss. It is liquid water that soaks up the signal.

- 4 GHz (C band): ≈ 0.1 dB
- 12 GHz (Ku band): ≈ 5 dB
- 20 GHz (Ka band): ≈ 12 dB

- **≈ 1.5 mm**: an average raindrop
- **≈ 15 mm**: wavelength at 20 GHz (Ka band)
- **≈ 75 mm**: wavelength at 4 GHz (C band)

![Every 10 dB of loss means the signal arrives with a tenth of its power. AI-generated illustration.](https://assets.planetpast.com/a/bf/bfb6b17c4d98e05e.jpg)

- **Rain**: liquid water: strong loss
- **Snow, ice**: no comparable loss

Chapter V · The dish that steers

#### Why rain gets in the way

Via Satellite (2003): raindrops absorb energy from passing radio waves, and attenuation grows with rain density and as the wavelength approaches the size of a raindrop (about 1.5 mm across on average). In 25 mm/h rain over a 5 km path, losses are about 0.1 dB at 4 GHz, about 5 dB at 12 GHz (Ku band) and about 12 dB at 20 GHz (Ka band); operators add a “rain margin” of extra power, and high-rain regions suffer much more degradation. eoPortal: Starlink’s user links use the Ku and Ka bands.

Try it: switch between a dry sky and a tropical storm. The drop in signal strength in the scene is schematic.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [Via Satellite (Feb 2003): rain degradation and its implications for satellite communication](https://satellitetoday.com/telecom/2003/02/01/cover-story-rain-degradation-its-implications-for-satellite-communication); [eoPortal (ESA): Starlink satellite constellation (altitudes, more than 10,000 in orbit in March 2026, Ku/Ka bands, phased-array terminals, laser links, krypton thrusters, deorbiting)](https://directory.eoportal.org/satellite-missions/starlink)

## Chapter VI · Down to the ground

### Down to the ground
*Chapter VI*

Every path ends at a gateway.

The satellite is only a relay. Your request goes up to it, then down to a ground station, a gateway, which connects it to the rest of the internet. Far from any gateway, at sea or over remote land, newer Starlink satellites pass data between each other with lasers, until it reaches one that can see a ground station. Either way, every terminal, satellite and gateway answers to the same operator's network.

- Dish → satellite (radio)
- Satellite → gateway (radio)
- Gateway → the rest of the internet
- The answer comes back the same way

![Optical links first flew on Starlink’s V1.5 satellites; SpaceX said all future satellites would carry them. AI-generated illustration.](https://assets.planetpast.com/a/95/951aa9c344f15160.jpg)

- **Terminal**: registered to an account
- **Satellites**: commanded by the operator
- **Gateways**: run by or for the operator

Chapter VI · Down to the ground

#### Gateways and lasers

eoPortal: the Starlink system relies on ground stations and user terminals, and SpaceX planned to install ground stations in Google’s data centres; optical inter-satellite laser links first appeared on V1.5 satellites, and SpaceX said laser terminals would be added to all future satellites. Wikipedia, Iridium: inter-satellite links let calls pass between neighbouring satellites before coming down.

Try it: route a request through a nearby gateway, or across laser links to a distant one. The routes are schematic, not real network maps.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [eoPortal (ESA): Starlink satellite constellation (altitudes, more than 10,000 in orbit in March 2026, Ku/Ka bands, phased-array terminals, laser links, krypton thrusters, deorbiting)](https://directory.eoportal.org/satellite-missions/starlink); [Wikipedia: Iridium satellite constellation (66 active satellites at ~781 km; service from 1 November 1998; inter-satellite links)](https://en.wikipedia.org/wiki/Iridium_satellite_constellation)

### 

That is where the control lies. Because each terminal connects through the operator's satellites, the operator can decide where the service works, and on what terms. In Ukraine, SpaceX switched Starlink on in February 2022, and later blocked it in Russian-occupied areas with geofencing. In February 2026, only approved terminals were left working. In October 2026, terminals were capped at a travelling speed of about 100 miles, or 160 kilometres, an hour, which hit fast-moving drones. Ukraine said the limit was lifted on 24 October. None of this needs anyone to touch a single dish. It is set inside the network, from far away.

- Feb 2022: Activated country-wide; first terminals arrive
- 2022–23: Occupied areas geofenced out
- Feb 2023: Some military uses restricted
- Feb 2026: Whitelist: unlisted terminals cut off
- Oct 2026: Speed cap, then restored

- Where: geofenced areas
- Who: approved terminals only
- How: speed and usage limits

- **~100 mph**: travelling speed above which links failed
- **>250 mph**: stable after restoration, per Ukraine’s defence ministry

- **0**: dishes that need touching to change the rules

Chapter VI · Down to the ground

#### Control by design

Wikipedia, Starlink in the Russo-Ukrainian war: SpaceX activated Starlink in Ukraine after a request on 26 February 2022, with the first terminals arriving on 28 February; it blocked service in Russian-occupied areas, including Crimea, by geofencing, restricted some military uses such as controlling combat drones from February 2023, and in February 2026 cut service to all terminals in Ukraine not on a whitelist, which disrupted Russian military communications. NPR: the October 2026 limits capped speeds at about 100 mph; Ukraine’s defence ministry said connectivity was stable for objects faster than 250 mph after the restoration recorded on 24 October.

Who ordered the October limit is disputed: Musk said SpaceX closed a “loophole”; Ukrainian officials denied breaking the terms; the Trump administration denied a role (CBS, NPR, Washington Post). Try it: turn on a geofence, or a speed cap, on the schematic map.

The globe, orbits, beams and waves are teaching models. Satellites are drawn far larger than life, and orbit heights are to scale only where a number is shown.

Sources: [Wikipedia: Starlink in the Russo-Ukrainian war (activation in 2022, terminals, geofencing, Starshield, whitelisting in 2026)](https://en.wikipedia.org/wiki/Starlink_in_the_Russo-Ukrainian_war); [NPR via KPBS (24 Oct 2026): Musk says SpaceX did restrict Starlink, as Ukraine says the tech has been restored](https://www.kpbs.org/news/international/2026/10/24/musk-says-spacex-did-restrict-starlink-as-ukraine-says-the-tech-has-been-restored); [CBS News (24 Oct 2026): Ukraine says Starlink speeds restored as Elon Musk admits SpaceX throttled service](https://www.cbsnews.com/news/ukraine-starlink-drone-spacex-musk-speed-restriction/); [Washington Post via The Spokesman-Review (25 Oct 2026): Elon Musk says SpaceX was behind restrictions to Ukraine’s Starlink access](https://www.spokesman.com/stories/2026/oct/25/elon-musk-says-spacex-was-behind-restrictions-to-u/)

## Epilogue

### 

From one satellite hanging high above the equator to thousands racing just overhead, the trick is the same: a relay in the sky. What changed is speed, scale, and how much can depend on one network. So the next time you see a flat dish in a field, remember: behind it is a whole network, and someone deciding how it runs. Who that should be is a question the world is still arguing about.

- 1945: Clarke describes the still orbit
- 1962: Telstar: first live transatlantic TV
- 1993: Thaicom 1
- 1998: Iridium: 66 low satellites
- 2019: First 60 Starlink satellites
- 2026: >10,000 Starlinks; Ukraine slowdown

- **1 network**: satellites, gateways and accounts
- **1 operator**: who sets where and how it works

- Stills are AI-generated
- Globe uses NASA Blue Marble imagery
- Satellites, beams and routes are schematic

Epilogue · Sources

#### Sources

Every fact in this film comes from the sources below. Latency times are computed from the speed of light where stated. The chapter stills and pictures are AI-generated illustrations; the globe uses NASA Blue Marble imagery. Satellites, beams, coverage circles and routes are schematic and not to scale unless a number is shown. On the October 2026 slowdown in Ukraine, the parties’ accounts differ and are attributed to each.

Sources: [CBS News (24 Oct 2026): Ukraine says Starlink speeds restored as Elon Musk admits SpaceX throttled service](https://www.cbsnews.com/news/ukraine-starlink-drone-spacex-musk-speed-restriction/); [NPR via KPBS (24 Oct 2026): Musk says SpaceX did restrict Starlink, as Ukraine says the tech has been restored](https://www.kpbs.org/news/international/2026/10/24/musk-says-spacex-did-restrict-starlink-as-ukraine-says-the-tech-has-been-restored); [Washington Post via The Spokesman-Review (25 Oct 2026): Elon Musk says SpaceX was behind restrictions to Ukraine’s Starlink access](https://www.spokesman.com/stories/2026/oct/25/elon-musk-says-spacex-was-behind-restrictions-to-u/); [Wikipedia: Starlink in the Russo-Ukrainian war (activation in 2022, terminals, geofencing, Starshield, whitelisting in 2026)](https://en.wikipedia.org/wiki/Starlink_in_the_Russo-Ukrainian_war); [Wikipedia: line-of-sight propagation (VHF and above; radio horizon)](https://en.wikipedia.org/wiki/Line-of-sight_propagation); [Lakdiva.org: Arthur C. Clarke’s 1945 proposal in Wireless World (letter “Peacetime Uses for V2”, February 1945) and the geostationary orbit](https://lakdiva.org.lk/clarke/1945ww/); [Wikipedia: Telstar 1 (launch 10 July 1962; first live transatlantic TV 23 July 1962; orbit 952 × 5,933 km)](https://en.wikipedia.org/wiki/Telstar_1); [NASA: Telstar opened era of global satellite television](https://www.nasa.gov/content/telstar-opened-era-of-global-satellite-television); [ESA: types of orbits (GEO 35,786 km; LEO 180–2,000 km, ~90 min; constellations)](https://www.esa.int/Our_Activities/Launchers/Types_of_orbits); [Wikipedia: Thaicom (Thaicom 1 launched 18 December 1993)](https://en.wikipedia.org/wiki/Thaicom); [NewSpace Economy (15 Jul 2025): satellite internet in 2025, HughesNet and Viasat struggle to keep up with Starlink (Ookla median latency figures)](https://newspaceeconomy.ca/2025/07/15/satellite-internet-in-2025-hughesnet-and-viasat-struggle-to-keep-up-with-starlink/); [Britannica: Starlink (LEO below ~1,600 km; many satellites needed; Iridium 1998; first 60 satellites in May 2019; collision avoidance)](https://www.britannica.com/topic/Starlink); [Wikipedia: Iridium satellite constellation (66 active satellites at ~781 km; service from 1 November 1998; inter-satellite links)](https://en.wikipedia.org/wiki/Iridium_satellite_constellation); [eoPortal (ESA): Starlink satellite constellation (altitudes, more than 10,000 in orbit in March 2026, Ku/Ka bands, phased-array terminals, laser links, krypton thrusters, deorbiting)](https://directory.eoportal.org/satellite-missions/starlink); [Analog Devices, Analog Dialogue: phased array antenna patterns, part 1 (beam steering by phase shift)](https://www.analog.com/en/resources/analog-dialogue/articles/phased-array-antenna-patterns-part1.html); [Via Satellite (Feb 2003): rain degradation and its implications for satellite communication](https://satellitetoday.com/telecom/2003/02/01/cover-story-rain-degradation-its-implications-for-satellite-communication); [International Astronomical Union: satellite constellations (brightness, streaks, radio interference)](https://iauarchive.eso.org/public/themes/satellite-constellations/)