I remember reading about a study that shows that gravity travels at the speed of light. However, I've also heard that most mainstream scientists believe that space is capable of faster-than-light travel.

OK Tyler,
The first thing I thought of as I created your spacecraft launch in my head was the wake. The wake in my mind would become a black hole itself sucking in all and everything.
The achievement of light speed has been overcome in Canberra Australia a few short year ago. admittedly it was with a gassious atom, but it registered at the target before it was supposed to if travelling at light speed.
The second point of the matter is that the idea of inter stellar travel is to spread the genetic pool as far as possible to prevent extinction. If this is the case then I have another thought for you to consider.
[The Station Construction World Investigation Dart. A probe that dwarfs the "Enterprise" sails into a solar system continuing it's inventory of planets comets and meteors. Year one begins when the SCWID has completed its survey of the solar system and concluded that there is sufficient material to construct a habitat system and activates the constructors. Seventy-five years later, when the ringworld is complete, this is a series of space wheels suspended inside the outer tubing and protected from the outer solar system debris by a shield of layered material designed to muffle impacts. The centrifuge wheels, which make up the habitat, rotate by using tiny linear motors and permanent magnets that separate the wheels from the outer wall by a distance of ten millimeters. Every hundred thousand kilometers is a space dock. The interior diameter of a wheel is five kilometers; the outside adds a further two kilometers. The spherical docking bay is fifteen kilometers from internal surface to internal surface. The outer skin is five hundred meters thick. This skin covers the entire globe of the docking bay as well as the entire length of the ringworld.
Like a spear thrust through a ball, the docking shaft in space dock points from the sun to the outer worlds and beyond. The linear canon that makes an important part of the shaft can extend a thousand kilometers toward the sun or deep space to launch or capture a spacecraft, while lighting is supplied through a telescopic mirror system that intersects the launch tube in the center.
Fembots called Mothers complete with a thousand frozen embrios inside awake and begin the process of gardening. From microbes for the soil to worm eggs and insect larva, all have to be introduced to the new soil that covers most of the internal shell. Simple plants are followed by more complex plant systems until the trees are growing comfortably and larger animals like lizards and birds can be introduced to prey on the plants and insects that by this stage are thriving. A further fifty years will pass before the small mammals are introduced and another twenty-five before the first of the frozen human embryos in each of the mothers drops into their artificial wombs and begin to grow. These are the space colonists that will fill the galaxy. After four generations, four SCWID are launched to colonise four other systems and so on and so on.]
from "The Colony(c)" a novel by myself