The plane with the orange nose just barely visible under the X-15 launch pylon is a T-38A. F-104s were also often used to chase the X-15. What a great picture! Image Unavailable, Please Login
Honestly I can't tell. It does look kind of like a F-104 a few hundred feet below and to the right of the X-15. Silver fuselage with white wings. The resolution of the photo isn't the best so I can't tell for sure. If that is a ground feature, it sure looks a lot like a F-104! Image Unavailable, Please Login
Here's a picture of my local car club and 6 trips to Pima Air Museum down in Tucson, AZ. B36 is a huge plane. Image Unavailable, Please Login
I wonder if that is exactly what they were doing. The T-38 watches (and photographs) the drop, while the F-104 comes by at Mach 2 so it can at least hang with the X-15 for a few seconds.