 &gt;&gt; to stay in Pluto orbit, either you carry a lot of fuel with you to slow down<p>Gravity assist can be used often used to speed up a spacecraft, but can also be used to slow it down.<p><pre><code>  https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Gravity_assist
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In addition, atmospheric drag can also be used to slow down a spacecraft passing a planet.