Earth 2654, Space Travel

The traveling from one world to the other in the Solar System relies on two different transportation “networks”. First a large number of unmanned shuttles, slow moving and inexpensive, that use traditional orbital mechanics to move cargo from one world to the other. Equipped with fusion engines, the shuttles have limited maneuverability, and are not atmosphere worthy. Transfer of cargo from the shuttles to the moons, planets, and asteroids is made with smaller shuttles that do the landings.

The second system is made of faster ships, mainly commercially operated ones, but some private ships as well, that run with more powerful fusion drives and can cover interplanetary distances in a shorter time than the long haul cargos. The fusion drives require a lot of heavy hydrogen, hence the booming hydrogen economy of the gas giants. Such ships can cover the 4.5 billion kilometers between the Earth and Neptune, for instance, in four weeks, and can reach the outermost worlds within six months. Trips are comprised of an acceleration phase, during which there is gravity due to that acceleration, a “cruise” phase, where there is no gravity (spinning ships to induce gravity was tried at some point, but turned out to be causing more space sickness than simple weightlessness), and a deceleration phase, where gravity is present again. Some of the fastest and most advanced ships skip the “cruise” phase altogether, and accelerate up to half of the trip, roll-over, and decelerate the second half of the trip. This allows constant gravity for the passengers, and maximum comfort. The prodigious amounts of energy needed to accomplish this mean that those ships tend to be cramped, because of the amount of fuel to bring along.

For most passengers, space travel is not fun, not to mention expensive. Cramped quarters, no gravity, limited food, all reason that most people try to limit their movement between worlds to the strict minimum. That’s one of the reason most colonization efforts tend to work very well: once you’ve gone to the trip there, you don’t want to go back…

The colony ship sent to Alpha Centauri was a monster: a huge ship, hosting hundreds of people. Its journey lasted close to 50 years. The 4.37 years of delay in signals to and from the Centauri Colony make contact with it very rare, and no one has traveled to Alpha Centauri since the original expedition.