Just a bit of warning: Software Engineering in Aerospace is NOT fun. You're basically in a supporting role to the hardware and system engineers designing the spacecraft. It's pure drudgery... process to the point of absurdity, specs and tasks being spoon fed to you with little room for creativity and/or problem solving, etc.
The pay, benefits, and level of respect on the job reflect all of that.
If you really want to work in space, I'd go and get a MS (or higher) in aerospace engineering or space systems engineering and work at the systems level.
I got out of aerospace and am much happier for it.