Starlink is a constellation of small broadband satellites operated by SpaceX. With over 6,000 spacecraft on orbit and growing, it is by far the largest satellite system ever built. The goal: deliver high-speed, low-latency internet anywhere on Earth, including rural areas where ground infrastructure is impossible or unaffordable.
The Constellation Design
Starlink satellites operate in Low Earth Orbit at roughly 540–570 km altitude across multiple orbital "shells" with inclinations between 53° and 97°. The mix of inclinations ensures coverage from the equator to the poles. Each satellite weighs about 260 kg (Gen 1) or 800 kg (Gen 2), and a single Falcon 9 launch delivers 22–60 satellites at a time.
Phased-Array Antennas
Both the satellites and the user terminals use phased-array antennas — flat panels with hundreds of small elements that steer beams electronically rather than mechanically. That's how the famous "Dishy" terminal can lock onto a satellite passing overhead in seconds without any moving parts.
Laser Inter-Satellite Links
Newer Starlink satellites have optical laser links that talk to four neighbors at once, forming a mesh in space. Data can hop satellite-to-satellite at the speed of light in vacuum (faster than fiber on the ground!) before dropping to a ground station. This is what lets Starlink serve oceans, polar regions and Ukraine's frontlines without a nearby landing station.
Frequencies
- Ku-band (12–18 GHz) — primary user downlink/uplink.
- Ka-band (26–40 GHz) — gateway links to large ground stations.
- E-band (60–90 GHz) — proposed for future capacity boosts.
Performance
Typical residential users see 50–250 Mbps downlink and 20–40 ms latency — comparable to cable internet. Maritime, aviation and enterprise tiers push higher, while priority/global roaming options support travel and shipping.
Concerns
Starlink's brightness has frustrated astronomers, and its sheer numbers have raised collision-avoidance and space-debris concerns. SpaceX has added sunshades, lowered reflectivity, and built autonomous collision-avoidance using public conjunction data.
Watch a Starlink Train
The night after a Starlink launch you can often see a "train" of bright dots crossing the sky in single file — newly deployed satellites that haven't yet raised their orbits. Use the live tracker to find the next pass over you.