Our solar system will last for billions of years. That is a very long time, but it is not forever. The goal of the Living Universe Foundation is the assured survival of life. To achieve this, humanity must spread to other star systems.
Until humanity can achieve space travel at a minimum of 10% of the speed of light, there is little point in traveling beyond our solar system. Rather than sending out primitive ships, which take thousands of years to get anywhere, it is better to spend a few extra centuries developing technology, and then build fast ships which can cross the void in at most a few decades. Any ship sent at, say, 1% of the speed of light would arrive to be greeted by people that left many years later and arrived many years earlier.
Although space is largely empty, it is not a perfect vacuum. When traveling at velocities as high as 10% of the speed of light, the occasional dust particles act as a thin gas, creating aerodynamic resistance and radiation hazards. At high speeds, gas molecules will strike the ship with energies comparable to cosmic radiation. For seed ships to successfully carry a cargo of life from one star to the next, its design must be streamlined and its construction must include either passive (material) or active (electromagnetic) shielding. Unlike the ships of science fiction, the look of the star ships of Galactia will be sleek and aerodynamic.
Human or Transhuman?
It is possible that centuries from now humanity will have changed little. Biotechnology will be required to overcome space waste; however as a whole we may not evolve much. If this is the case, then interstellar travel will be similar to interplanetary travel--life is transported as it is, although perhaps in suspended animation.
Alternatively, it is entirely possible that our advancements in technology will partially or completely evolve the human race beyond biology. Humanity today may not recognize humanity of the future. If so, how we travel between stars will be equally as different. On the extreme end; if our consciousness becomes digital in nature, it will be possible to send an automated ship to the distant stars, and transmit ourselves once a communication array is established.
The degree of which humanity evolves will be dependent on future generations and developments in technology. At the moment there is no way to accurately map out how we will expand beyond our solar system into the Milky Way. We can safely assume that humanity, in whatever form it transcends to, will be the torchbearers, bringing the green spark of life to the Galaxy.
Isn't the Living Universe Foundation Forgetting the Universe?
How humanity expands into other galaxies is currently beyond anyone's ability to discuss in terms other than wild speculation. Spreading life to the larger universe will eventually become the 9th phase of the Living Universe Foundation, but that is a task for future generations.
There are groups out there actively involved in speculation about how we could get beyond the Sol system and what we could build "out there". If you have a link you would like added, please let us know.