Small light maybe 30,000 ft. Tracking south to north. Began changing directional vectors quickly. 90 degree angles ,

Sitting with my grandchild on the front porch. Pointing out various stars, planets and aircraft. I pointed out what I thought was a satellite. He wanted to know what satellites do and we started talking. He says Papa it’s moving around. I look back up and this object is moving around with crazy vector thrust making 90 degree turns. It lasted about 15 seconds and then went behind a cloud. Waited for the cloud to pass but nothing else was observed