I went ahead and used your hunch regarding the author and quickly built upon my own memories of reading Asimov. I think perhaps the novel you MIGHT be looking for, and I'm not completely sure is Asimov's "Nemesis"Asimov's "Nemesis" which shares several of the same themes that you have mentioned.
Without spoiling to much, the book centers around a group of space colonists who attempt to flee the overcrowding and "base" nature of earth through the use of a Colony ship which gets as close to light speed as possible. They eventually arrive at their destination and attempt to set up a colony on a moon that is covered in a very low form of life which becomes hostile to them (Bacterial spreads). A parallel plot runs through the story of those humans trapped on earth attempting to leave as well and develop FTL technology in order to do so, spurred on by the sudden fleeing and "betrayal" of the space colonists.