well it does mention how they had 'political pressures' to move to C++. I believe C++ is great when you are talking about performance, something which is absolutely critical when you are talking about calculating minute adjustments to trajectories on the fly really fast.

But the programming language we are looking for must be a 'hackable' one - something for you which you can hack together a fix or bypass fairly easily and quickly in case of situations encountered in interplanetary space. C++ is definitely not something I see capable of achieving that.