Captain Lee Ashby, USN, was ready to retire. He wanted no more adventures in his life, no more uncertainty. But he found himself taking command of the Vortex Rider, leading a crew whose makeup made no military or scientific sense, except as colonizers of a new planet- and they had now way of knowing whether the planet was already inhabited.
Used availability for John Boyd's Barnard's Planet
July 1975 : USA Hardback
1975 : USA Mass Market Paperback