Rocket launches may dominate headlines, but the true bottleneck in space exploration lies not in reaching low Earth orbit (LEO), but in venturing beyond it. From LEO to the Moon or Mars, spacecraft still require costly kick stages or oversized boosters. A decades-old idea known as the skyhook could change that equation.
A skyhook is a rotating orbital tether: essentially, a long, strong cable that swings a spacecraft from one orbit to another, much like a sling. Unlike the space elevator concept, a skyhook looks much more buildable with current technology. By lowering the cost of Earth/Moon & interplanetary transport, skyhooks and related tether technologies could help make space travel beyond LEO economically feasible. The linked interview with Marcus Landgraf, from ESA, connects this to breaking resource limitations and enabling prosperity through space expansion.
It could even help with getting in and out of orbit; you get a craft up to the right altitude and the sideways velocity can be supplied by the hooks, and then returned to them to deorbit.
I believe there was a startup that was developing one, but I have no idea if that’s still ongoing.