Virgin Orbit is finally ready to launch. The company plans to take off from Mojave Air and Space Port in California this weekend, and the mission will fly their modified Boeing 747 carrier craft and LauncherOne to altitude before detaching from the 747. Then, it will use it's own rocket engines to make the rest of the trip into space. The use of a carrier craft means it can take off from existing runways, and the rocket is a two-stage expendable vehicle that can carry around 660 lbs to 1,100 lbs to orbit. If all goes well at the demonstration launch, Virgin will plan for its first paid launch this summer.