Set the throttle to 0% after you enable SCA. If there's something in the way it will stop and you can take over manually when you get back to the cockpit.I've had a bad day for crashing into planets. I'm multi tasking while exploring using supercruise assist intending to orbit the next planet I want to DSS until ready. Supercruise assist is crashing me into planet exclusions zones about 30% of the time