Beyond Earth
The Solar System
Internet
Right now, rovers on Mars, astronauts on the ISS, and probes at the edge of the solar system are all sending data home. But they can't use the internet you're on right now. Here's why - and what we're building instead.
1.3s
to the Moon
22 min
to Mars
22.5 hr
to Voyager 1
Why can't we just use the internet in space?
The internet you're using right now runs on TCP/IP - a protocol that assumes three things. All three are wrong in space.
It assumes speed
TCP needs a fast "handshake" before sending data. On Earth, that takes milliseconds. To Mars, a single handshake takes up to 44 minutes. A webpage needing dozens of handshakes would take days to load.
Analogy: Imagine a phone call where every sentence takes 22 minutes to arrive.
It assumes connection
TCP expects an always-on link. In space, planets rotate, orbits shift, and every 26 months the Sun blocks Earth-Mars signals for two full weeks. When TCP loses connection, it panics and gives up.
Mars rovers literally go on autopilot during solar conjunction. Zero internet.
It assumes clean signals
TCP treats lost packets as congestion and slows down. In space, cosmic radiation and distance cause constant errors - signals from Mars are 20 billion times weaker than a watch battery. Slowing down wastes precious contact windows.
NASA's DSN antennas detect signals fainter than a snowflake hitting the ground.
So what IS the solar system internet?
It's not one network. It's a network of networks - just like the internet itself.
Think about how the internet works on Earth: your home Wi-Fi connects to your ISP, which connects to backbone cables, which connect to data centers worldwide. Different technologies, different networks, all stitched together by common protocols. The solar system internet does the same thing - connecting separate space networks with a protocol called DTN (Delay-Tolerant Networking) that works like a postal service instead of a phone call.
Layer 1
Local Networks
Each location has its own network. The ISS has Wi-Fi 6. The Moon is getting LunaNet. Mars has relay orbiters. Like neighborhoods in a city.
Layer 2
Relay Satellites
Relay satellites forward data between locations - like highway systems connecting neighborhoods. NASA's TDRS fleet, China's Queqiao, and future lunar/Mars relay constellations.
Layer 3
Ground Stations
Where space internet meets Earth internet. NASA's DSN, ESA's ESTRACK, and China's CDSN - massive dish antennas that catch whisper-faint signals from across the solar system.
The Glue
DTN Protocol
DTN connects everything. Unlike TCP/IP's "phone call" approach, DTN works like a postal service: store the message, wait for a connection, forward it, repeat. Co-invented by Vint Cerf - the same person who invented the internet.
How a photo gets from Mars to your screen
1. Mars Rover
Perseverance or Curiosity captures an image and sends it via short-range radio to a satellite overhead.
Mars internet →2. Mars Orbiter
A relay satellite (like MRO) stores the data and waits for Earth to come into view, then beams it across space.
Relay network →3. Deep Space Transit
The signal travels at light speed across 55-400 million km. Nothing can make this faster - it's physics.
Latency calculator →4. DSN Antenna
A massive 70-meter dish detects the incredibly faint signal and converts it back to digital data.
Ground stations →5. Your Screen
From the ground station, data travels via normal fiber optic cables and the regular internet to NASA's site - and you.
Earth satellite internet →Total journey: hours to a full day. The light-speed transit is 3-22 minutes, but orbital alignment and relay scheduling add more waiting time.
Everything is changing right now
2025-2026 is a turning point. Three revolutions are happening at once - and they're transforming space internet from a patchwork of mission-specific links into actual infrastructure.
Lasers replacing radio
NASA's DSOC proved 267 Mbps via laser from beyond Mars - 100x faster than radio at the same distance. The ISS already has a 1.2 Gbps laser link. By 2030, most new space missions will use optical communications.
How laser comms work →Commercial providers entering
NASA stopped assigning new TDRS missions in 2024 and is buying from commercial providers instead. Intuitive Machines won a $4.82B contract to be the Moon's first ISP. The ARPANET-to-commercial-internet transition is happening in space.
The lunar ISP race →Permanent infrastructure
Instead of each mission building its own link, shared relay constellations are being deployed. ESA Moonlight, NASA LunaNet, and China's Queqiao are building the equivalent of cellular towers - for the Moon.
Compare space networks →Key moments
Apollo broadcasts from the Moon at 51.2 kbps →
First TDRS relay satellite - ISS connectivity begins →
NASA proves 622 Mbps laser from the Moon (LLCD) →
SpaceX launches first Starlink satellites →
ISS gets 1.2 Gbps via laser (ILLUMA-T) →
DSOC sets deep-space laser record: 267 Mbps. Nokia tests 4G on Moon.
Artemis II laser comms. First commercial lunar relay. Vast Haven-1 + Starlink. →
LunaNet + Moonlight fully operational. Permanent lunar internet.
Explore deeper
Each topic has detailed guides, comparison tables, and interactive tools.
ISS Internet
600 Mbps
How 7 astronauts share 600 Mbps via relay satellites
Lunar Internet
1.3s delay
From 51 kbps Apollo to 260 Mbps Artemis laser comms
Mars Internet
3-22 min delay
3 to 22 minutes for every message to the Red Planet
Deep Space Comms
160 bps
160 bps from Voyager 1 at 24 billion km away
Laser Comms
267 Mbps
267 Mbps via laser from deep space - the optical revolution
Space Protocols
DTN/BP
Why TCP/IP breaks in space and what replaced it
Tiangong Internet
1.2 Gbps
China's independent space internet via Tianlian relays
Commercial Stations
1+ Gbps
Gigabit broadband in orbit by 2027
Space Networks
4 Networks
DSN, TDRS, ESTRACK, CDSN - the backbone
Latency Calculator
0s - 22h+
Calculate signal delays to anywhere in the solar system
Fun Facts
50 facts
Mind-blowing facts about internet in space
Space internet starts on Earth
The same companies building satellite internet for your home are building the backbone for space. Starlink's 10,000+ satellites use inter-satellite lasers - the same technology NASA is deploying for lunar and deep space links.
Compare
Satellite Internet on Earth
Starlink, HughesNet, Viasat, Amazon Kuiper - compared by speed, price, and availability.
Security
VPN for Satellite Users
Your satellite data passes through ground stations. Encrypt everything.
Learn
50 Mind-Blowing Facts
The ISS has Wi-Fi 6. Voyager is still online after 48 years. And more.
11 space networks covered · Updated March 2026 · Facts API