The Pythagoras Sling uses a lengthy graphene string pulled via two hoops suspended from simple parachutes to rapidly accelerate a projectile into orbit. Graphene string will likely become widely available over the next two decades. If it works as expected, the Pythagoras Sling launch system could greatly reduce the cost of getting into space compared to any current rocket-based system and could help accelerate space development. Total cost of the fully reusable launch system could be as low as $1M for small and medium sized satellites so cost per kg could be two orders of magnitude cheaper than today. Apart for human spacecraft or more delicate satellites that need low g-forces, the system needs little or no fuel to achieve orbit, only ground electricity, so would be safer and more environmentally friendly as well as cheaper than current rocket-based approaches.
The breakthrough was to see that large parachutes could be used as effective temporary ‘sky anchors’ for hoops, through which tethers may be pulled that are attached to a projectile. The parachutes will of course fall, but will remain high enough to fill their purpose during the entire launch. No other space launch concept has ever used parachutes in this way.
This system is not yet feasible because of limitations of current materials, but will quickly become feasible in a wide range of roles as materials specifications improve with ongoing graphene and carbon composite development. Eventually it will be capable of launching satellites into low Earth orbit, and greatly reduce rocket size and fuel needed for human space missions. The system was invented by UK futurologist Dr Ian Pearson will the kind assistance of Prof Nick Colosimo. Graphene itself was also a UK discovery.
More detail is here: Pythagoras Sling article