15 Titans!?!? I'm sure that if you doubled them, you could get a lot further.
No, it doesn't work like that. If he had less, it would be slower, and as you know, if something goes faster, it has a higher orbit. One valiant? Too slooow. He would be better off with a titan. Probably could return back to earth and do a powered landing with the same stage
. xd this is fun