<p>We can access trajectory data for the Voyagers via the <a href="https://ssd.jpl.nasa.gov/horizons/" rel="nofollow noreferrer">Horizons</a> system of JPL. For various reasons, Horizons didn't have great trajectory data for these spacecraft. However, in 2022, R. Jacobson (former Voyager navigation), was able to reconstruct these trajectories. There's some info about that in these Horizons data files:<br />
<a href="https://ssd.jpl.nasa.gov/api/horizons.api?format=text&amp;MAKE_EPHEM=NO&amp;COMMAND=%27Voyager%201%27" rel="nofollow noreferrer">Voyager 1</a><br />
<a href="https://ssd.jpl.nasa.gov/api/horizons.api?format=text&amp;MAKE_EPHEM=NO&amp;COMMAND=%27Voyager%202%27" rel="nofollow noreferrer">Voyager 2</a></p>
<p>The Voyagers are gradually losing speed as they climb out of the Solar System's gravity well: they're trading kinetic energy for potential energy. They have enough kinetic energy to escape our gravity well, but they will continue to lose speed over the years and centuries to come.</p>
<p>The current speeds of Voyager 1 and 2 relative to the Sun are roughly 17 km/s and  15 km/s, respectively. Earth's orbital speed is around 30 km/s, so there are periods each year when the Voyagers have negative speed relative to Earth.</p>
<p>Here are some speed graphs for Voyager 1, produced using Horizons data. The timestep is 7 days, and each data point is for 0:00 TDB, which is close to midnight UTC.</p>
<p>First, here's Voyager 1's speed relative to the Solar System barycentre.
<a href="https://i.sstatic.net/E3tNI.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/E3tNI.png" alt="Voyager1 speed, barycentre" /></a></p>
<p>Here's its speed relative to the Sun, which looks a little wobbly, mostly because of the effects of Jupiter and the other giant planets on the Sun.</p>
<p><a href="https://i.sstatic.net/XgM4Y.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/XgM4Y.png" alt="Voyager1 speed, Sun" /></a></p>
<p>And here's its speed relative to the Earth.</p>
<p><a href="https://i.sstatic.net/FmyWD.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/FmyWD.png" alt="Voyager1 speed, Earth" /></a></p>
<p>And here's Voyager 2, relative to the Earth.</p>
<p><a href="https://i.sstatic.net/kH4LY.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/kH4LY.png" alt="Voyager2 speed, Earth" /></a></p>
<p>The last two graphs look quite similar. We can see that most of the time, the Voyagers are definitely heading away from Earth, but for almost 3 months each year, we're outpacing them.</p>
<p>Here's my <a href="https://sagecell.sagemath.org/?z=eJyVWG1z2kgS%5Fs6vmCi5Q3KwDDjObrjlbrGDK941hgKSrZzNqQY0AsV6O81gQ1z%2D79fdM0ICZ6%5FuXGXQ9HT39Ns83cKyLDYWKg%5FFg2A5T5biOOdKMJ8rzoI8jdmnNA%2D%5Fp4lkQZozzhTPl0Kxeepvawz%2DeOLDP0vnUuQPYbJkC5EokRM9i1LFQuWyGrH%2DkYdKiYTNt2w0YO0xcreb7Zbb%5FOC2PhDL5wwOFj6S227zzG2%2DI%5FIg9cMgBDraEIXLlWIq5w8iYiqMheH%2DqVCyx13xqWBrt2sWuF2rhXGW5orlogH%5F%5F14LqWSNfA7WyUKlaSSZYYnytbfgi5XQ%2DzFX6FsUzl0VLu7BXcM3WfCI55dpDhwYhVot2D13D3fttRTDIJBCdS95JIUD7Os8AkZrpVQmOycnUvrutyxyEy65u0wfTngWnqxMRrwgjIQLFKsGH96DyGWYJigOIUX%5F5lwKbxH7SLKs2qD3e9%5Frjz71B0Cof%2D1P6jVaedOvoz6SvvQvpsMxkIefp97nm6vpBKm%5FD46BNO5feqPr3g0xXo57g76mTb5Oplrh1cX4sl4DHd7FcDxGyvX07URTrnvn%5FWvSdjPUlI%5F962nPmxaki8kX73I4HvSmO9uG5795H3vTXlVq2ju%5FJgve100Of92lxo75RobfRTdMlH3qODVfBCwQarHysJptXbkNU6ANJoGg8CvN8FPAJ4Rwnkph0tGhatLxCzCAr968mQwva09FXJ9rF8PBoHfzES160vqfwZf%2DzbRPAXjSZwFtMu2Np970akDWP9HZRB6OqtQ0I2J%5F5E2u%5FlkQBRLh7D6cjWagVa%2DzHN0EIxxaQ%5F0Cd1HFbpZKZUMtNegid5%5FqugzrHVZXYqPqzw2GxSNhJ0yyNW7YdVBWb6C%5FzrNWWlZULlwpeL5Y2bnVG12xL%5F3x5Gp407mTR%5Fbd5Mix6Aa5qNtxl3m6zuyW1hEGOzWvuqxSpzq6%2DKddCaw%5FeJ4AJnQYnlAIhZI9mWcwer6Gm78CmlzkYaZwFy%5F5U0Xvs%2DUYvIkPDLf%5FIZ27N3eQw77tHtFjf9ivml5YHKPimzQRh0ZaN0NGd6Y%5FvppYzsHuvh6dFrXOE1JViQbW2KHmfVkRVTmiMBFSp5d4XJlFoSKqfWiDdZdY7rc0TGzavz3rtN7PnCIkBOtdFu9ydNvqzGjH4PphxGLnX9MS8VnCY0FJd4%5FunP%2DSddMEfqDtQu%5F8X9pMFNH4Btu%5FxuAXXnMZpZmws2aDZS1zb63pSmg6SwMoGkFh1D0tazKVAqu%2DSxsQ2zbB2Kyp1y1Yt3Ddqh5vA%2D0YGB12wuwNPm%2Dajjl%5FLr7byoNbZw5%5FzXpZlqebMMbGo7AHJUoCzIgFhwfGFROJL3Xklxj2W%2D3CUeZQRWcsTNj3MNNawWv8um13Zs7sB0J6t9OGXfaW9t4e7B2TqKmC1%2Dx8HUY%2DOxffQwjhYp0%5FCGNL9gBq8dwj%2DtA%2DNVClToWiWAFSYrwSSJUNIibnpAat0ibyXGCt6Zjm6SPu2FreOIGOQia3oA7dBU1lzfvon4Igq2ZJ2wANNk7YaUlDa6CWumjSEbCgMvzecbxm%5FQ1fqMJbNGu3Rza%2D7UJumxCyLfzboBBO9beY5raDqvDAdnml00cX%5FIb02egOiOCZJA%2DiECsbrSaa1oMUWDiz8qrqUEHrzlANaHSq6ssQvoi4iVa1LLWuhnYF%2DmGI1wL8pbqMOQCB2qjuJxVH5%2DnGtn5Znf59LCKuQhj4ZCaE%5F8sJkCynUStAoGt9Sbd8CbFqWcU961q%5Fnn74YCET9a6uBdPU6XEvy4%5Fbp5buokR7p2k%5FW7qndq2ffJLCuY4I7xo0tEndZCF3qZLdab6GR3KleE6jFE5d5kIkpAAOxubeet9gj6GvVt32Qb%2DGAx%2DWxSNfq9Rb0zRZdHNT%5FADBCYylNp7LUlP9zgugn4hIQNHARY0El4oBgiOO7ElZL4C%2DZjIj1xHW74vpw5Uwame2U4R1tzaKKLYlE0a1uhKVVeG7%2Dd71LnP4nzawlIlsJWKRA4ee8tN14r%5F6M1%2DqoOshYBem04IQHs%2Drdhf8etmizOat1Ft2vVF3bjvHrRnBgEQAQJaZQSia3eEuGHKnaJNwV%5F62b%2DFrNsItHTv2Vwoa%2D20dhRxFtxJIVHy1ShQuoQt0oESPUPdtc0bYWWWYph1oIQUDWEkc5kRCxfKWkvZyiZaHjcJ4kawh1sBho6ZKnSEsKbyoDN4KAAZ4TopKjOARrjHCgDhZit3QnL8vXroKnpavO3iFEigOha9Z0O3iE7kT%5FuaDfdiegyjlFFSIAdRUuQSPEftazWYJv2bm1MJluVA0CiwrdvdNHfB7oW%2D94nFW2gHlGrK%5F7LCBdaFdlBHCv20M%2DlYxhtcExJQPTi6ns33eBosBT4AVpAybdVwpbLIWVfkA1jECPnbUvW2wiOzct8IIQqPA8QoEwaLiABeqBOao5r4ecmkvKEqWUxi8uNJ1qFUaZ6NomOUssSvwgYAE59wPeaQxW5dhlGJLoP4OJWwsgPF4R8W6NeQYVXT1GTC%5FINcxaqhWfWANNNcTcnfc0%2DAZy8YqDZnQHcNhapnzbAVIrFa0JPVkGo1ZxD4CTbjAPhmlDeKhbrgKzWJW4Dx9NvSgq7aR6Fodk7cRRh1nQpuMs1C%2DomxP3LwYKx55PAqXSQxA1bVy%5FL3ghbbAMk6eBc%5FWnlH%5Fk9JIBGoXl%5FtHgEeqq3ChbFMHCuBPdANrXEkbdpCnCpY%2DA5KZVgw39KkCrM93RdcDQMmBoNuioSzz0KdYdW9v15Bhwpy1wUohIaxWzL%2DluTXDZru493a%5FQnTbR7e7xazQxzdCehGfw2tH99YqAcVCRSeSoZ4Kj6c7sds6w9fIJa3ww8TY9QRCk3f%5F6EtX92Bbh8gpezA20vKSUV4yeGtRsph4SevZXjJ2PY5uzIH0nMY7L%2DNqZRc3qiq7q%2DGe71cawjYOExiqYo6z5cjFJXZXfOKbojFvCVOABeZD%2Dj4mOUTIpts828E%2D3nPAnl0iDkykwiNEI0TA0TCAyiJPLRnzKNrlnHBBj0DziC%5FuLWr4kMv9MtQVY1Wd%2D7aGaYVDuUFrgD4QpvqdhtzcgO2NQ5c3O5c32uUfhEEP9FopTMsbHYMNxeBkPyamBiSUuBbwyAq76f4M4TI6TvQMV9gdmFnCKn7acmGUszDT8E0vw5WtLFlaxSH8QdgkvCsNECijTvAEb0GJZoJqxlhxyYJ9fEekWsGEbAcu4KNvO1qdXKWP9sip%5FQc3zixf&amp;lang=sage" rel="nofollow noreferrer">plotting script</a>. You can use any major body that Horizons knows for the observing center, and any major or minor body as the target. Please see the Horizons manual for further details.</p>
<p>If you'd like to see the Voyager trajectories in 3D, please see my answer <a href="https://astronomy.stackexchange.com/a/49823/16685">here</a>.</p>
<p>Here's a plot of the distance from Earth to both Voyagers, produced using a Horizons script from that answer. The timestep is one month.</p>
<p><a href="https://i.sstatic.net/lSEN1.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/lSEN1.png" alt="Voyagers distance from Earth" /></a></p>
<hr />
<p>Here are speed plots for the three other spacecraft on Solar System escape trajectories, Pioneers 10 and 11, and New Horizons. Note that &quot;The circumstances pertaining to the regeneration of the [Pioneer] spacecraft trajectory source files [...] are not well known&quot;.<br />
<a href="https://ssd.jpl.nasa.gov/api/horizons.api?format=text&amp;MAKE_EPHEM=NO&amp;COMMAND=-23" rel="nofollow noreferrer">Pioneer 10</a> <a href="https://ssd.jpl.nasa.gov/api/horizons.api?format=text&amp;MAKE_EPHEM=NO&amp;COMMAND=-24" rel="nofollow noreferrer">Pioneer 11</a></p>
<p><a href="https://i.sstatic.net/b8OZS.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/b8OZS.png" alt="Pioneer 10 speed" /></a></p>
<p><a href="https://i.sstatic.net/IE4JJ.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/IE4JJ.png" alt="Pioneer 11 speed" /></a></p>
<p><a href="https://i.sstatic.net/lbGBg.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/lbGBg.png" alt="New Horizons speed" /></a></p>

CC BY-SA 4.0
2024-03-08T06:30:50.743Z
The previous version of this answer had a typo in the speed graphs & plotting script. The Y axis was labelled "km/s" instead of "m/s". Oops.
PM 2Ring
CC BY-SA 4.0
2024-03-08T07:57:42.423Z
"The circumstances pertaining to the regeneration of the [Pioneer] spacecraft trajectory source files". Is this a reference to the Pioneer Anomaly?
JohnHunt
CC BY-SA 4.0
2024-03-08T08:01:32.970Z
@JohnHunt No, it's just a consequence of the fact that NASA didn't save every little detail on computers 50 years ago.
PM 2Ring
CC BY-SA 4.0
2024-02-09T14:13:23.423Z
2024-03-08T07:37:04.767Z
2024-03-08T07:37:04.767Z
PM 2Ring
<p>According with NASA JPL the earth catches up with the spacecraft because Earth is moving a lot faster than the spacecraft. Can one calculate the times when the spacecraft gets closest to Earth</p>

CC BY-SA 4.0
2024-02-09T03:14:49.693Z
Can you link the NASA JPL article?
Nilay Ghosh
CC BY-SA 4.0
2024-02-09T04:47:46.857Z
It's on Twitter (X) posted today.
dimitri33
CC BY-SA 4.0
2024-02-09T06:59:48.187Z
Also Twitter can be linked
planetmaker
CC BY-SA 4.0
2024-02-09T12:32:40.843Z
There are two Voyagers, one heading north of the ecliptic, one heading south. Voyager 2 is currently travelling at ~15.032 km/s away from the Sun.
PM 2Ring
<galaxy><solar-system><earth><space><earths-orbit>
Voyager spacecraft distance from Earth
dimitri33
# Voyager spacecraft distance from Earth

(Asked by: username_0 on 2024-02-09)

According with NASA JPL the earth catches up with the spacecraft because Earth is moving a lot faster than the spacecraft. Can one calculate the times when the spacecraft gets closest to Earth

**Tags:** galaxy, solar-system, earth, space, earths-orbit
> **Comments:**
> **username_1**: Can you link the NASA JPL article?  
> **username_0**: It's on Twitter (X) posted today.  
> **username_2**: Also Twitter can be linked  
> **username_3**: There are two Voyagers, one heading north of the ecliptic, one heading south. Voyager 2 is currently travelling at ~15.032 km/s away from the Sun.  

---

## 1 answers

### Answer by username_3 on 2024-02-09. Score: 11 | Accepted answer

We can access trajectory data for the Voyagers via the [Horizons](https://ssd.jpl.nasa.gov/horizons/) system of JPL. For various reasons, Horizons didn't have great trajectory data for these spacecraft. However, in 2022, R. Jacobson (former Voyager navigation), was able to reconstruct these trajectories. There's some info about that in these Horizons data files:  
[Voyager 1](https://ssd.jpl.nasa.gov/api/horizons.api?format=text&MAKE_EPHEM=NO&COMMAND=%27Voyager%201%27)  
[Voyager 2](https://ssd.jpl.nasa.gov/api/horizons.api?format=text&MAKE_EPHEM=NO&COMMAND=%27Voyager%202%27)

The Voyagers are gradually losing speed as they climb out of the Solar System's gravity well: they're trading kinetic energy for potential energy. They have enough kinetic energy to escape our gravity well, but they will continue to lose speed over the years and centuries to come.

The current speeds of Voyager 1 and 2 relative to the Sun are roughly 17 km/s and 15 km/s, respectively. Earth's orbital speed is around 30 km/s, so there are periods each year when the Voyagers have negative speed relative to Earth.

Here are some speed graphs for Voyager 1, produced using Horizons data. The timestep is 7 days, and each data point is for 0:00 TDB, which is close to midnight UTC.

First, here's Voyager 1's speed relative to the Solar System barycentre.
[![Voyager1 speed, barycentre](https://i.sstatic.net/E3tNI.png)](https://i.sstatic.net/E3tNI.png)

Here's its speed relative to the Sun, which looks a little wobbly, mostly because of the effects of Jupiter and the other giant planets on the Sun.

[![Voyager1 speed, Sun](https://i.sstatic.net/XgM4Y.png)](https://i.sstatic.net/XgM4Y.png)

And here's its speed relative to the Earth.

[![Voyager1 speed, Earth](https://i.sstatic.net/FmyWD.png)](https://i.sstatic.net/FmyWD.png)

And here's Voyager 2, relative to the Earth.

[![Voyager2 speed, Earth](https://i.sstatic.net/kH4LY.png)](https://i.sstatic.net/kH4LY.png)

The last two graphs look quite similar. We can see that most of the time, the Voyagers are definitely heading away from Earth, but for almost 3 months each year, we're outpacing them.

Here's my [plotting script](https://sagecell.sagemath.org/?z=eJyVWG1z2kgS%5Fs6vmCi5Q3KwDDjObrjlbrGDK941hgKSrZzNqQY0AsV6O81gQ1z%2D79fdM0ICZ6%5FuXGXQ9HT39Ns83cKyLDYWKg%5FFg2A5T5biOOdKMJ8rzoI8jdmnNA%2D%5Fp4lkQZozzhTPl0Kxeepvawz%2DeOLDP0vnUuQPYbJkC5EokRM9i1LFQuWyGrH%2DkYdKiYTNt2w0YO0xcreb7Zbb%5FOC2PhDL5wwOFj6S227zzG2%2DI%5FIg9cMgBDraEIXLlWIq5w8iYiqMheH%2DqVCyx13xqWBrt2sWuF2rhXGW5orlogH%5F%5F14LqWSNfA7WyUKlaSSZYYnytbfgi5XQ%2DzFX6FsUzl0VLu7BXcM3WfCI55dpDhwYhVot2D13D3fttRTDIJBCdS95JIUD7Os8AkZrpVQmOycnUvrutyxyEy65u0wfTngWnqxMRrwgjIQLFKsGH96DyGWYJigOIUX%5F5lwKbxH7SLKs2qD3e9%5Frjz71B0Cof%2D1P6jVaedOvoz6SvvQvpsMxkIefp97nm6vpBKm%5FD46BNO5feqPr3g0xXo57g76mTb5Oplrh1cX4sl4DHd7FcDxGyvX07URTrnvn%5FWvSdjPUlI%5F962nPmxaki8kX73I4HvSmO9uG5795H3vTXlVq2ju%5FJgve100Of92lxo75RobfRTdMlH3qODVfBCwQarHysJptXbkNU6ANJoGg8CvN8FPAJ4Rwnkph0tGhatLxCzCAr968mQwva09FXJ9rF8PBoHfzES160vqfwZf%2DzbRPAXjSZwFtMu2Np970akDWP9HZRB6OqtQ0I2J%5F5E2u%5FlkQBRLh7D6cjWagVa%2DzHN0EIxxaQ%5F0Cd1HFbpZKZUMtNegid5%5FqugzrHVZXYqPqzw2GxSNhJ0yyNW7YdVBWb6C%5FzrNWWlZULlwpeL5Y2bnVG12xL%5F3x5Gp407mTR%5Fbd5Mix6Aa5qNtxl3m6zuyW1hEGOzWvuqxSpzq6%2DKddCaw%5FeJ4AJnQYnlAIhZI9mWcwer6Gm78CmlzkYaZwFy%5F5U0Xvs%2DUYvIkPDLf%5FIZ27N3eQw77tHtFjf9ivml5YHKPimzQRh0ZaN0NGd6Y%5FvppYzsHuvh6dFrXOE1JViQbW2KHmfVkRVTmiMBFSp5d4XJlFoSKqfWiDdZdY7rc0TGzavz3rtN7PnCIkBOtdFu9ydNvqzGjH4PphxGLnX9MS8VnCY0FJd4%5FunP%2DSddMEfqDtQu%5F8X9pMFNH4Btu%5FxuAXXnMZpZmws2aDZS1zb63pSmg6SwMoGkFh1D0tazKVAqu%2DSxsQ2zbB2Kyp1y1Yt3Ddqh5vA%2D0YGB12wuwNPm%2Dajjl%5FLr7byoNbZw5%5FzXpZlqebMMbGo7AHJUoCzIgFhwfGFROJL3Xklxj2W%2D3CUeZQRWcsTNj3MNNawWv8um13Zs7sB0J6t9OGXfaW9t4e7B2TqKmC1%2Dx8HUY%2DOxffQwjhYp0%5FCGNL9gBq8dwj%2DtA%2DNVClToWiWAFSYrwSSJUNIibnpAat0ibyXGCt6Zjm6SPu2FreOIGOQia3oA7dBU1lzfvon4Igq2ZJ2wANNk7YaUlDa6CWumjSEbCgMvzecbxm%5FQ1fqMJbNGu3Rza%2D7UJumxCyLfzboBBO9beY5raDqvDAdnml00cX%5FIb02egOiOCZJA%2DiECsbrSaa1oMUWDiz8qrqUEHrzlANaHSq6ssQvoi4iVa1LLWuhnYF%2DmGI1wL8pbqMOQCB2qjuJxVH5%2DnGtn5Znf59LCKuQhj4ZCaE%5F8sJkCynUStAoGt9Sbd8CbFqWcU961q%5Fnn74YCET9a6uBdPU6XEvy4%5Fbp5buokR7p2k%5FW7qndq2ffJLCuY4I7xo0tEndZCF3qZLdab6GR3KleE6jFE5d5kIkpAAOxubeet9gj6GvVt32Qb%2DGAx%2DWxSNfq9Rb0zRZdHNT%5FADBCYylNp7LUlP9zgugn4hIQNHARY0El4oBgiOO7ElZL4C%2DZjIj1xHW74vpw5Uwame2U4R1tzaKKLYlE0a1uhKVVeG7%2Dd71LnP4nzawlIlsJWKRA4ee8tN14r%5F6M1%2DqoOshYBem04IQHs%2Drdhf8etmizOat1Ft2vVF3bjvHrRnBgEQAQJaZQSia3eEuGHKnaJNwV%5F62b%2DFrNsItHTv2Vwoa%2D20dhRxFtxJIVHy1ShQuoQt0oESPUPdtc0bYWWWYph1oIQUDWEkc5kRCxfKWkvZyiZaHjcJ4kawh1sBho6ZKnSEsKbyoDN4KAAZ4TopKjOARrjHCgDhZit3QnL8vXroKnpavO3iFEigOha9Z0O3iE7kT%5FuaDfdiegyjlFFSIAdRUuQSPEftazWYJv2bm1MJluVA0CiwrdvdNHfB7oW%2D94nFW2gHlGrK%5F7LCBdaFdlBHCv20M%2DlYxhtcExJQPTi6ns33eBosBT4AVpAybdVwpbLIWVfkA1jECPnbUvW2wiOzct8IIQqPA8QoEwaLiABeqBOao5r4ecmkvKEqWUxi8uNJ1qFUaZ6NomOUssSvwgYAE59wPeaQxW5dhlGJLoP4OJWwsgPF4R8W6NeQYVXT1GTC%5FINcxaqhWfWANNNcTcnfc0%2DAZy8YqDZnQHcNhapnzbAVIrFa0JPVkGo1ZxD4CTbjAPhmlDeKhbrgKzWJW4Dx9NvSgq7aR6Fodk7cRRh1nQpuMs1C%2DomxP3LwYKx55PAqXSQxA1bVy%5FL3ghbbAMk6eBc%5FWnlH%5Fk9JIBGoXl%5FtHgEeqq3ChbFMHCuBPdANrXEkbdpCnCpY%2DA5KZVgw39KkCrM93RdcDQMmBoNuioSzz0KdYdW9v15Bhwpy1wUohIaxWzL%2DluTXDZru493a%5FQnTbR7e7xazQxzdCehGfw2tH99YqAcVCRSeSoZ4Kj6c7sds6w9fIJa3ww8TY9QRCk3f%5F6EtX92Bbh8gpezA20vKSUV4yeGtRsph4SevZXjJ2PY5uzIH0nMY7L%2DNqZRc3qiq7q%2DGe71cawjYOExiqYo6z5cjFJXZXfOKbojFvCVOABeZD%2Dj4mOUTIpts828E%2D3nPAnl0iDkykwiNEI0TA0TCAyiJPLRnzKNrlnHBBj0DziC%5FuLWr4kMv9MtQVY1Wd%2D7aGaYVDuUFrgD4QpvqdhtzcgO2NQ5c3O5c32uUfhEEP9FopTMsbHYMNxeBkPyamBiSUuBbwyAq76f4M4TI6TvQMV9gdmFnCKn7acmGUszDT8E0vw5WtLFlaxSH8QdgkvCsNECijTvAEb0GJZoJqxlhxyYJ9fEekWsGEbAcu4KNvO1qdXKWP9sip%5FQc3zixf&lang=sage). You can use any major body that Horizons knows for the observing center, and any major or minor body as the target. Please see the Horizons manual for further details.

If you'd like to see the Voyager trajectories in 3D, please see my answer [here](https://astronomy.stackexchange.com/a/49823/16685).

Here's a plot of the distance from Earth to both Voyagers, produced using a Horizons script from that answer. The timestep is one month.

[![Voyagers distance from Earth](https://i.sstatic.net/lSEN1.png)](https://i.sstatic.net/lSEN1.png)

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Here are speed plots for the three other spacecraft on Solar System escape trajectories, Pioneers 10 and 11, and New Horizons. Note that "The circumstances pertaining to the regeneration of the [Pioneer] spacecraft trajectory source files [...] are not well known".  
[Pioneer 10](https://ssd.jpl.nasa.gov/api/horizons.api?format=text&MAKE_EPHEM=NO&COMMAND=-23) [Pioneer 11](https://ssd.jpl.nasa.gov/api/horizons.api?format=text&MAKE_EPHEM=NO&COMMAND=-24)

[![Pioneer 10 speed](https://i.sstatic.net/b8OZS.png)](https://i.sstatic.net/b8OZS.png)

[![Pioneer 11 speed](https://i.sstatic.net/IE4JJ.png)](https://i.sstatic.net/IE4JJ.png)

[![New Horizons speed](https://i.sstatic.net/lbGBg.png)](https://i.sstatic.net/lbGBg.png)

> **Comments:**
> **username_3**: The previous version of this answer had a typo in the speed graphs & plotting script. The Y axis was labelled "km/s" instead of "m/s". Oops.  
> **username_4**: "The circumstances pertaining to the regeneration of the [Pioneer] spacecraft trajectory source files". Is this a reference to the Pioneer Anomaly?  
> **username_3**: @JohnHunt No, it's just a consequence of the fact that NASA didn't save every little detail on computers 50 years ago.  

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