<story><title>Space junk removal is not going smoothly</title><url>https://www.scientificamerican.com/article/space-junk-removal-is-not-going-smoothly/</url></story><parent_chain></parent_chain><comment><author>xoa</author><text>While I know Scientific American is a fairly mainstream targeted and softer science publication, this&lt;p&gt;&amp;gt;&lt;i&gt;And the problem is now poised to get much worse because of the rise of satellite “mega constellations” requiring thousands of spacecraft, such as SpaceX’s Starlink, a broadband Internet network.&lt;/i&gt;&lt;p&gt;really could have used a LOT more qualification particularly since it&amp;#x27;s become a major recent talking point. There is one ultimate sure-fire way to reduce space junk: &lt;i&gt;launch stuff to very low orbits&lt;/i&gt;. There is still some atmosphere (varying with heating and other factors) up a long ways in &amp;quot;space&amp;quot;, and it&amp;#x27;s only above 600km or so that orbital drag becomes negligible enough that lifetimes really stretch out. The ISS for example requires regular reboosts or it would decay back into the atmosphere.&lt;p&gt;SpaceX focusing on economics has made it feasible to start planning constellations of comm sats that are low and very low earth orbit, with the understanding that inherently their lifetimes will be measured in single digit years. But that&amp;#x27;s ok since they can be replaced so cheaply. This is much better, not worse. Even if they go offline or got hit, the debris would have a very restricted lifetime. The media should do a better job of conveying how cheaper $&amp;#x2F;kg to LEO opens up a lot of new possibilities in what regulations are feasible and how we think about the basics of satellite design. A simple &amp;quot;Mega constellation bad!&amp;quot; is all wrong, and that&amp;#x27;s not necessarily going to be intuitive to everyone.</text></comment>
<story><title>Space junk removal is not going smoothly</title><url>https://www.scientificamerican.com/article/space-junk-removal-is-not-going-smoothly/</url></story><parent_chain></parent_chain><comment><author>ryandrake</author><text>All I had to do is play a little Kerbal Space Program to understand how difficult it would be to clean up space junk in orbit. Orbit isn&amp;#x27;t like some 3D grid where you stick a roomba up there, and have it go back and forth until you get everything. Even if you have the technology that lets you grab anything you encounter, you first have to reach something. And then burn some fuel to match its orbit. And then burn some fuel to get to the next thing. And then burn some fuel to match that thing&amp;#x27;s orbit (more than before because you are now carrying more mass around).&lt;p&gt;It might be better to keep everything up there. Assuming the junk is re-usable in some way: If one day, we do manage to build some kind of industry in orbit, it will need to consume raw materials, and having all this scrap in orbit already means you saved most of the energy cost it would have taken to get all that mass up there.</text></comment>