14 CFR § 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.
When operating Class 2-High Power Rockets or Class 3-Advanced High Power Rockets, you must comply with the General Operating Limitations of § 101.23. In addition, you must not operate Class 2-High Power Rockets or Class 3-Advanced High Power Rockets -
(a) At any altitude where clouds or obscuring phenomena of more than five-tenths coverage prevails;
(b) At any altitude where the horizontal visibility is less than five miles;
(c) Into any cloud;
(d) Between sunset and sunrise without prior authorization from the FAA;
(g) Unless you observe the greater of the following separation distances from any person or property that is not associated with the operations:
(1) Not less than one-quarter the maximum expected altitude;
(2) 457 meters (1,500 ft.);
(i) Unless reasonable precautions are provided to report and control a fire caused by rocket activities.