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This is part of a short story posted on worldbuilding.se, but setting my story aside, it was recommended that the part about precision be asked here.

With what precision can an object be put on the moon, with today's technology?

This is specifically related to the accuracy of the de-orbit, and the assumption is that there is a will to impact the moon with an object with precision (I'm trying not to stray into worldbuilding territory right now).

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    $\begingroup$ What's your dV budget for the lander? $\endgroup$ – Deer Hunter Oct 11 '15 at 18:11
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    $\begingroup$ The de-orbit maneuver will not be the only maneuver in the sequence, so anything really goes, esp. if you have close-up photos for visual navigation. $\endgroup$ – Deer Hunter Oct 11 '15 at 18:15
  • $\begingroup$ @DeerHunter for the purpose of the question, it would be a place that we have landed on before. I don't know if that means we have precise imagery or not, but maybe that helps to answer? $\endgroup$ – Mikey Oct 12 '15 at 1:43
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Really precise. Apollo 12 landed only 600 feet off of target. That's the only landing with precision that I can find, but presumably we could do it at least as well today.

The moon is easier to land precisely on than, say, Mars or Earth, because of the lack of atmosphere. The fact that it is so close to Earth also allows for a spacecraft to be precisely on the correct trajectory, with Mars there is always a small amount of uncertainty, which can really add up.

As for how accurate with a hard landing, the best analog was LCROSS, which intentionally targeted a point on the Moon. The miss distance was 146 m for the primary stage, 766m for the less precise part.

I imagine if you wanted to, you could probably improve that by an order of magnitude, although I have nothing with which to base that claim. This could be accomplished by using GPS, visual maps, and precise knowledge of it's gravitational field, among others.

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    $\begingroup$ We have better models of Lunar gravity field. We have experiments on GPS use beyond LEO (and can field auxiliary subsats around the Moon if need be). We have visual navigation software and much better on-board computing power. These are the key enablers, IMHO. $\endgroup$ – Deer Hunter Oct 12 '15 at 7:08

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