# Apollo's trajectory to the moon taking orbiting the sun into account

**URL:** <https://boards.straightdope.com/t/apollos-trajectory-to-the-moon-taking-orbiting-the-sun-into-account/734076>\
**Category:** Factual Questions\
**Created:** [October 9, 2015, 8:59pm UTC](https://boards.straightdope.com/t/apollos-trajectory-to-the-moon-taking-orbiting-the-sun-into-account/734076 "2015-10-09T20:59:24Z")\
**Posts on this page:** 3\
**Page:** 1

<div class="post-metadata">

**Author:** ![D18](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@D18](https://boards.straightdope.com/u/D18)\
**Post date:** [October 9, 2015, 8:59pm UTC](https://boards.straightdope.com/t/apollos-trajectory-to-the-moon-taking-orbiting-the-sun-into-account/734076/1 "2015-10-09T20:59:24Z")

</div>

I’ve been reading up on the trajectory that the Apollo missions took to the moon. There’s lots of images out there that show the path relative to the Earth and the Moon. (E.g., [this here.](https://en.wikipedia.org/wiki/Trans-lunar_injection#/media/File:Trans-lunar_injection.svg)).

What I’m curious about is what the path would look like not from the Earth, but from the perspective of someone looking down on the solar system. I know it’s always complicated to specify a particular place in space, but let’s say someone were above the earth, perpendicular to the plane of the moon’s orbit, and high enough that they could see both the earth and moon moving beneath them. (But they are firing enough engines so they stay the same distance from the sun, and are hovering above where the Earth was (relative to the Sun) at the time of the trans-lunar injection.

I’ve tried to google an image, but couldn’t find what I am looking for.

Or, perhaps it doesn’t make sense to even posit the scenario! 😉

---

<div class="post-metadata">

**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\
**Post date:** [October 9, 2015, 10:59pm UTC](https://boards.straightdope.com/t/apollos-trajectory-to-the-moon-taking-orbiting-the-sun-into-account/734076/2 "2015-10-09T22:59:07Z")

</div>

The orbital velocity of the earth/moon system around the sun is about 30km/s. Low earth orbit is about 7.8km/s relative to earth, and you need another 3km/s or so to do your translunar injection. What this means is that your path from the earth to the moon will look pretty much like a circle around the sun. Take the path in your picture, and trace it out while sliding it sideways 3x faster than you follow the path.

Disclaimer: everything I know about orbital mechanics I learned from Kerbal Space Program.

---

<div class="post-metadata">

**Author:** ![D18](https://avatars.discourse-cdn.com/v4/letter/d/c57346/32.png) [@D18](https://boards.straightdope.com/u/D18)\
**Post date:** [October 9, 2015, 11:21pm UTC](https://boards.straightdope.com/t/apollos-trajectory-to-the-moon-taking-orbiting-the-sun-into-account/734076/3 "2015-10-09T23:21:47Z")

</div>

Huh. That makes sense. Thank you.