Internal Payloads:......Internal payloads are carried in detachable nose and equipment bays in forebody of airplane.

External Payloads:......The SR-71 is not presently configured for external payloads; however, the aircraft can be modified for that purpose. Some SR-71 type aircraft have been configured to carry external payloads.

• Modified A-12 (M-12, mother ship): configured to carry D-21 drone (42 ft long, 19 ft span, 11,200 pounds), mounted on pylon on upper aftbody of airplane.
• YF-12A (a NASA configuration): carried a 9 foot, 18 inch diameter cylinder beneath mid section of airplane for experimental purposes.

Source: SR-71 Reconnaissance System, Executive Handbook