This is a beamliner. Beamliners are interstellar spacecraft propelled mainly by a large magnetic sail. Their name stems from their method of propulsion; by deflecting a tightly focused beam of charged smart-particles with a magnetic sail, or, in some cases, smaller momentum-exchange sails directed at the spacecraft from a beam projector station. The beamliner is accelerated out-system on such a beam up to its cruise velocity of 35% the speed of light (or .35c). It then coasts in interstellar space, before reactivating its magsail to start braking against the interstellar medium. Once in proximity to the destination system's beam station (about 200 AU), it then decelerates on that beam for about a year and docks with the station. Some designs have drive systems that allow them to drop into orbit around a specific planet after deceleration. Since beamliners require an active particle stream to brake on, they can only travel between systems advanced enough to host beam stations (although most do take advantage of passive braking techniques by using their magsails to shed velocity in the interstellar medium). Travel to an uninhabited or unexplored system requires a secondary deceleration method to slow down to orbital velocity, and is only done with robotic probes.
Before embarking on a beamliner en route to a settled exoplanet, passengers must spend several years undergoing extensive gene therapy in order to be placed under hibernation to survive the long journey through interstellar space. Although most trips take less than a century to complete, and particle streams are becoming capable of pushing beamliners to higher velocities, storing passengers in a state of suspended animation simply saves mass by eliminating the need for extensive life-support systems an active crew would require, such as providing and recycling consumables. Passengers only need to undertake this treatment once; so once augmented, they can safely undergo "coldsleep" again if they can obtain passage aboard another beamliner.
The energy needed to push a spacecraft to even sub-relativistic velocities (< 0.5c) is quite substantial. Thus, the mass of interstellar spacecraft must be reduced as much as practically possible. Most of the craftís mass comes from the magnetic sail itself. Although it is merely a series of very thin superconducting hoops, it is over 75 kilometers wide when fully deployed, and can total up to 40,000 kilograms. The next most massive part is the debris shield and crew modules. Such craft are often quite fragile in appearance, consisting largely of skeletal truss members made out of advanced lightweight composites. Even with such mass-saving designs, the raw energy need to accelerate interstellar spaceships to cruise velocity (or rather, the energy needed to power the particle stream to push the spacecraft) exceeds several tens of terawatts. Thus, beam projectors orbit close to the local star where solar power is cheap and abundant, using vast photovoltaic arrays to generate the monumental quantities of power necessary to push a ship across interstellar space. Obviously, orbiting close to a star presents its own unique technical problems, mainly shielding the stationís delicate components from the starís intense heat and occasional stellar flares.
Depending on the distance of the star system in question, most systems near Sol have enough beamliner traffic between them to service the system once every 4 or 5 years. Beamliners are spaced along their trajectories such that there is always one arriving every few years, even though an individual beamliner may take over a century to complete one route. Traffic volume can increase if a settled system develops into a terminus with multiple beam projector stations capable of handling multiple streams of traffic from different systems at the same time. Sol, being the first terminus system, was for a long time the hub of all outbound interstellar traffic, although it took several centuries to build up the infrastructure required to launch the first few missions. Although the network itself took nearly a millennium to reach its current size, today its growth has began to show dramatic increase as multiple star systems become advanced enough to start building their own beam stations and beamliner craft. It is expected that by the next millennium, the network will have expanded some 500 light years
While the network is most known for manned interstellar spaceflight, it has also made robotic exploration of the cosmos much faster and cheaper. Since probes are far lighter than any manned spacecraft, and also do not carry a fragile living payload, they can withstand higher accelerations and also easily achieve faster velocities. Thus, as it always has been, the frontiers of space exploration are expanded by robotic emissaries, followed by human explorers and settlers many years later.
This is the most common and popular style of beamliner, although other styles do exist.