Envelope Expansion [Aeronautics and Space] Law and Legal Definition

According to 14 CFR 437.3 [Title 14 Aeronautics and Space; Chapter III Commercial Space Transportation, Federal Aviation Administration, Department of Transportation (Parts 400 to 499); Subchapter C Licensing; Part 437 Experimental Permits; Subpart A General Information], Envelope Expansion means “any portion of a flight where planned operations will subject a reusable suborbital rocket to the effects of altitude, velocity, acceleration, or burn duration that exceed a level or duration successfully verified during an earlier flight.”