Finding the Vanguard

This is the 1st book in the Colony Ship Vanguard series. The Colony Ship Vanguard was one of seven colony ships launched from a damaged Earth in a desperate plan to carry human settlers to Earth equivalent worlds. The voyages would take generations, and the people on board, as well as the flora and fauna in huge biological habitats had to be stable. But something happened on the way. Now, over one hundred years later, Earth is all but dead. People survive only in Dome 17. Gretchen and Paul are one of the teams who partake in a risky and dangerous mission to try to recover a colony ship. They will be using two unproven technologies: faster-than-light travel and teleportation. Each of those have significant limits. But the missions to the colony ships are humanities one hope for long term survival. What will Gretchen and Paul encounter while they are trying to find the Vanguard?