Feel the delay
Ask a friend a question, and tell them to wait two full days to answer. That is how long a question to Voyager takes, there and back.
How Voyager works
It calls home on 23 watts.
That is less than the bulb in a fridge. It left Earth in 1977, and it is still sending us news from 25 billion km away. Scroll down to see how.
This is the simple version, because this device can't run the moving 3D. Try the 3D anyway
Scroll down ↓
10 instruments. 2 still on.
Every part has a job, and every part is still 1970s technology. Keep scrolling and watch it come apart.
How a message gets home · 01 / 04
Feel
Two instruments feel what is around Voyager: the thin gas and the magnetism between the stars. They are the last two still on.
Show me the real numbers
- Thin antennas
- 2, each 10 m long
- Magnetism sensor
- on a 13 m arm
- Status
- Both still on
How a message gets home · 02 / 04
Pack
A computer turns those readings into ones and zeros, 160 of them every second. One photo on your phone would not fit in its memory.
Show me the real numbers
- Memory
- about 69 kilobytes
- Data storage
- 8-track digital tape
- Fixed in 2024
- by radio, from 24 billion km
How a message gets home · 03 / 04
Send
The big dish beams them toward Earth as a radio signal. It has pointed at Earth for nearly 50 years. If it turned even a little too far, we would lose the signal.
Show me the real numbers
- Width
- 3.7 m
- Radio power
- about 23 W
- Data rate
- 160 bits per second
How a message gets home · 04 / 04
Wait
Even at the speed of light, the signal takes almost 24 hours to reach us. NASA hears it with dishes 70 meters wide.
The power · 01 / 05
It runs on heat.
Sunlight is far too weak out here. So three generators turn heat from plutonium into electricity, with no moving parts.
Show me the real numbers
- At launch
- about 470 W
- Today
- about 230 W
- Lost every year
- about 4 W
The cameras · 02 / 05
One last look back at us.
They sit on a platform that swings around to aim. They showed us Jupiter and Saturn up close. Their last picture was the Pale Blue Dot, in 1990. Since then, Voyager has sent readings, not pictures.
Show me the real numbers
- Cameras
- 2, wide and narrow
- Last picture
- February 14, 1990
- Status
- Switched off
The Golden Record · 03 / 05
A message for whoever finds it.
A gold-plated disc of sounds and pictures from Earth. It is about 30 cm wide, like an old record.
The particle sensors · 04 / 05
It felt where the Sun ends.
They counted fast particles from the Sun and from other stars for almost 49 years. That is how we learned the moment Voyager left the Sun's bubble. In 2026 they were switched off to save power.
Show me the real numbers
- Left the bubble
- August 25, 2012
- Cosmic ray sensor off
- February 25, 2025
- Particle sensor off
- April 17, 2026
Saturn's moon Titan · November 1980
One moon changed its path.
Titan is the only moon with a thick sky, so NASA sent Voyager 1 close to see it. That pass swung Voyager 1 up and out of the flat plane where the planets circle. It could never reach another planet. Its twin, Voyager 2, went on to Uranus and Neptune.
Show me the real numbers
- Closest to Titan
- November 12, 1980
- Planets after this
- None
- Voyager 2 reached
- Uranus 1986, Neptune 1989
The steering jets · 05 / 05
It steers by two stars.
It keeps watch on the Sun and on Canopus, one of the brightest stars in the sky. When it drifts, tiny puffs of fuel turn it back.
Show me the real numbers
- Guide star
- Canopus
- Fuel
- Hydrazine
- Job
- Keep the dish on Earth
Why only two are left
1981
Its power fades every year, so engineers switch instruments off, one at a time. Keep scrolling through the years.
About 450 watts left
Right now
Still sending.
On November 18, 2026, it reaches one light-day from Earth. Even light will need a full day to get there. Nothing we have built has gone this far.
The full 3D model
Take it apart yourself.
Turn it. Click any part. Press Take apart below. This is NASA's own 3D model of Voyager.
Away from the screen
Your turn.
Pack a record
Someone may find your message a billion years from now. Pick ten sounds that explain your life. What do you choose?
Fix it from far away
Ask a friend to do a task with their eyes closed, using only your words. Now you know how Voyager's engineers work.
Who builds machines like this?
Aerospace engineers.
They design things that fly, with math, science and a lot of testing. Voyager's first mission was planned for about five years. Good engineering has kept it going for nearly 50.