The M-67 (Myasishchev, name of manufacturer) was a high altitude reconnaissance aircraft developed by Myasishchev as a response to the United States' SDI program. The M-60 project was extensive, with variants featuring stealth or UAV capabilities, with some variants designed to carry a crew of 10-15 for 8 hours at an altitude of 20 kilometers. The program was later canceled, but subsequently may have been developed for civilian uses, such as ecological and stratosphere research.
Read more about this topic: Post-PFI Soviet/Russian Aircraft Projects