Can you name a novel about a human man who is the only survivor of a crash landing of a military spaceship on a planet that has cities left from extinct alien race?
Before the human man ended up an uncharted alien world, he and the rest of the crew evaded their enemies by hiding inside a large dusty cloud of gas. The cloud was large enough to hide an entire planetary system. One of the planets was human-habitable so they decided to land there. As it turns out, only one person survived the landing.
He was returned to normal health by robots that were remnants of extinct alien race. The aliens died long ago and left their cities and other technology mostly intact. The robots continued to maintain the world as they were programmed to do long ago. The man survived on this planet for several years after reprogramming a robot to be his friend, teacher, and butler.
Another human spaceship also crash lands on the planet. This time, the sole survivor is a woman, who just happens to be on the same side in the war. Her ship crashed after taking damage and tried to evade the enemy by hiding inside the same cloud of gas and dust.
The man tells the robots to restore her to health. They live together on the planet for a few weeks until an enemy ship discovers their world.
The two survivors use the robots to attack their enemies.
I've been trying to remember the name of this novel for a week. I think it was published sometime in the 1970's or 1980's.