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I remember reading a young-adult sci-fi novel many years ago (early 90's), but I don't remember much about it, even though I read it at least twice. I recall it being an important transitional book for me, and I think that's why I read it more than once. It was the first time I was intrigued by something more sophisticated.
As I recall, the basic plot involved a manned mission to explore a planet or a moon. There was a multi-legged alien that started out as a pet (but was discovered to be more than that?). I think it even had some kind of interesting color-changing behavior.
There was lots of talk about space-dust being a problem at the speeds they were traveling, and I think there was an emergency or two involving related hull-breaches. They might have sealed them with expanding glue from specialized guns?
The main character was a man.
...there was a woman as part of the mission.
...there was a cocoon of some kind. I think related to the pet alien?
The title might also have had the word "topaz" in it.