Satellite launching: Risky business

Huge disappointment in the climate science community today with the failure to reach orbit of a new climate monitoring satellite. Apparently, part of the rocket nosecone that sits over the satellite during launch failed to detach at the right moment. You can get a taste of what this means for climate science by reading this and this.

Given how high the stakes obviously are for climate science, one is left to wonder about the risk management of the whole operation. Rocket reliability has improved over the years (at least I assume it has), but space launching is still a pretty risky business. So is it typical for a company or research institute that commissions a new satellite to bet everything on a successful launch by building just one?

I realise these complex and delicate machines are built bespoke, but wouldn't it make sense to build two, just in case the first launch fails? If the launch succeeds, couldn't you still get some of your money back on the spare one by selling the parts or modifying it for a different mission?

Let's hear from you, space geeks.