This book covers the first British space launch that takes place from the Australian outback. As with most of Clarkes work, the emphasis is on the technology rather than the characters. If you have read 'Voyage' by Stephen Baxter, this can be seen as an earlier version, in the same way that H G Welles 'War of the Worlds' can be seen as the precursor of most subsequent alien invasion stories.
While 'Voyage' is an alternative history, Prelude was an alternative future when it was written. The British space programme came to a halt after we launched the first sattelite instead of continuing onwards. This book shows what could have happened if we had carried on with the project.
Many of the Ansari X Prize designs bear a remarkable resemblence to the aircraft and rocket design featured in the book, which in turn is launched from a linear accelerator. The story covers the design of the spacecraft and then the building and first launch. It's a good read and one that I re read every so often. I feel that The Sands Of Mars could be set 50-100 years after this book, and althogh Sands is not a sequel it could be considered as part of a sequence along with many of Clarkes short stories and novels.