After several months of playing and repeated attempts - I have made it to Sag A!!!!!!
I would post a picture but I don't know how to hide it behind a "Spoiler" tag, and I don't want to spoil the view for those who haven't been there.
Thought I was going to die there. I scanned the black hole and saw a marker called the centre. Raced toward it and got too close to the black hole. The temperature was rising dangerously and in my panic I couldn't get away. Managed to pull away with some damage to my ship's hull (down to 67% ) I think I scanned the centre marker.
Now the long journey back to Sol.