Whilst not asking for spoilers, are the Rama sequels worth reading for answers to the questions posed in the original?
In particular is the nature and purpose of the unseen aliens explained?
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In particular the nature and purpose of the unseen aliens?
Those aliens get explained in Rama Revealed (the 4th book in the series).
The Rama sequels are very different from the original book's vector. Rama serves as a background, but the main scope is about the human race ways of society. If you're interested in that as a topic, they are well worth reading.