We are not going to conquer the solar system with tethers and inflatable dinghies. We need real HARDware to do this right. There's no way I'd be willing spend months in space, living inside an inflatable structure while being spun around on the end of a thin cord. If it were to break, the crew would be flung out into the void of deep space.

Here's my plan.

First I would develop a new series of launch vehicles based on shuttle hardware. The main launcher would be a stretched ET with 4 or 5 SSMEs located underneath. It would be able to carry cargo either on top with an inline configuration or carry oversized cargo piggyback like the current shuttle system. In the inline mode, up to eight SRBs would be able to be used, while with side mounted cargo, up to four SRBs could be used. This system could lift well over 200 tons to LEO in its maxed out configuration.

The second launcher would be a Delta IV/Atlas V sized launcher. It would use SSMEs just like the HLLV, but with only one or two per stage. Instead of three core stages, two SRBs would be used if needed to give the rocket a faster liftoff from the pad. I just didn't like the way the Delta IV Heavy roasted in its exhaust before climbing skyward.

With the launchers built, now it's time to design the craft for them. For the medium lift rocket, I'd design a capsule to carry several astronauts to LEO and bringing them back to the surface. I'd also design an unmanned cargo version of the same capsule for delivering equipment and supplies. For the HLLV, I'd design a second generation shuttle for construction projects in orbit. It would be somewhat larger than the current shuttle to accommodate larger payloads. Since the main engines would be located underneath the launcher, no main engines would be needed on the shuttle. Although a couple of air breathing engines would be nice to expand its landing options. The current tiles would be replaced with a metallic TPS. I'd also strengthen the frame and landing gear so it could land with payload.

Besides launching shuttles, the HLLV could also be used to launch large single module space stations (think Space Island Group). These stations could be used for anything from space hotels to life science labs and even small space manufacturing facilities. Such stations could be built and sold to private costumers to help open up LEO to the private sector. It would also be useful in launching sections for deep space exploration craft and infrastructure for other deep space applications such as Moon/Mars bases and asteroid mining equipment. Such equipment could be launched to a large duel keel space station for assembly or to be sent by space tug to its final destination.