There are several. Here's one. http://hopsblog-hop.blogspot.com/2016/08/lunar-sky-hook.html http://hopsblog-hop.blogspot.com/2016/08/lunar-sky-hook.html https

There are several. Here's one. http://hopsblog-hop.blogspot.com/2016/08/lunar-sky-hook.html http://hopsblog-hop.blogspot.com/2016/08/lunar-sky-hook.html https://hopsblog-hop.blogspot.com/2016/04/liftport-lunar-tether.html https://hopsblog-hop.blogspot.com/2016/04/liftport-lunar-tet... There's also a wikipedia article: https://en.wikipedia.org/wiki/Skyhook_(structure) https://en.wikipedia.org/wiki/Skyhook_(structure)