Cosmos 1614

Launch data:

Mission details:

• Involved in the recovery operations were four vessels of the Black Sea fleet, namely three recovery vessels (the Yamal, Donbass and Sevan) and the cruiser Leningrad, as weIl as Beriyev Be-12 and Antonov An-26 airplanes and Kamov Ka-25 helicopters. While Cosmos-1517 was successfully retrieved by the Yamal, it was later revealed that Cosmos-1614 was lost, having either burned up in the atmosphere or sunk in the Black Sea. The recovery vessels, aircraft and helicopters searched the 70 x 30 km landing ellipse for about a week, but to no avail. Talking about the cause of the mishap many years later, State Commission leader Gherman Titov said that "while fixing one problem, engineers had created another".
• Despite the failure to recover the final vehicle, it was felt that enough data had been gathered during the four orbital flights and a fifth mission was reportedly cancelled. Several of the recovered BOR-4 vehicles were later put on display at Russian and international exhibitions. The Russians later said the missions had allowed them to test the effects of aerodynamic, temperature and acoustic loads as weIl as vibrations on the heatshield between altitudes of 100 and 30 km and speeds of between Mach 25 and Mach 3. Particularly helpful had been the temperature data obtained in critical areas such as the nosecap and the underbelly of the vehicle. The BOR-4 missions had helped to determine the ideal size of gaps between the tiles, measure the "catalytic activity" of the heatshield in real plasma conditions and also to study the risks associated with losing one or more tiles. The flights had also made it possible to "outline measures to reduce the mass of Buran'sheatshield", although there is no evidence those measures were actually implemented.