Legacy Regulations

This page is intended as a repository for legacy launch and reentry regulations (Part 415/417, Part 431, or Part 435) that were removed from the CFR on March 10, 2026. Licenses issued under Legacy Regulations expired no later than March 9, 2026, and no new license applications are being accepted under legacy regulations. Vehicle operators needed to come into compliance with Part 450 to continue operations after March 9, 2026.

If you are seeking information on a new license, permit, or approval, please use our Commercial Space Transportation Assistance Tool.

Legacy License Guidance Materials

Title Publication Date
450 Crosswalk Mapping to Legacy Regulations (PDF) 11/2020
Guide to Reusable Launch and Reentry Vehicle Software and Computing System Safety (PDF) 7/2006
Guidance for Medical Screening of Commercial Aerospace Passengers (PDF) 1/2006
Guide to Probability of Failure Analysis for New Expendable Launch Vehicles (PDF) 11/2005
Guide to Verifying Safety-Critical Structures for Reusable Launch and Reentry Vehicles, Version 1.0 (PDF) 11/2005
Guide to the Identification of Safety-Critical Hardware Items for Reusable Launch Vehicle Developers (PDF) 5/2005
Guide to Reusable Launch and Reentry Vehicle Reliability Analysis (PDF) 4/2005
Guide to Commercial RLV Operations and Maintenance Version 1.0 (PDF) 3/2005
Non-traditional Flight Safety Systems and IVHM (PDF) 8/2003
Guide to RLV Safety Validation and Verification Planning Version 1.0 (PDF) 9/2003
Supplemental Application Guidance for Unguided Suborbital Launch Vehicles (MS Word Docs) 8/1998
Advisory Circular 431.35-2A: Reusable launch and reentry vehicle system safety process 7/2005
Last updated: Tuesday, March 10, 2026