Ultra-telephoto photography is easily achieved with your telescope and Minolta MD camera by purchasing this T-Mount Adapter for Minolta MD Cameras.  You'll need to take precautions to minimize vibrations, such as locking up the mirror if possible as well as using a cable release or remote control to fire the shutter.


Note:
NOTE: Your camera will need to be in fully manual exposure mode, although some cameras may also work in aperture-priority auto-exposure mode.  Additionally, if there is a switch on the camera which chooses the focus mode, that switch must indicate manual focusing.