The BOR-4 (БОР-4Russian: Беспилотный Орбитальный Ракетоплан 4, Bespilotnyi Orbital'nyi Raketoplan 4, "Unpiloted Orbital Rocketplane 4") flight vehicle is a scaled (1:2) prototype of the Soviet SpiralVTHL (vertical takeoff, horizontal landing) spaceplane. An uncrewed, subscale spacecraft, its purpose was to test the heatshield tiles and reinforced carbon-carbon for the Buran space shuttle, then under development.[1]
Several of them were built and flown between 1982 and 1984 from the Kapustin Yar launch site at speeds of up to Mach 25. After reentry, they were designed to parachute to an ocean splashdown for recovery by the Soviet Navy. The testing was nearly identical to that carried out by the US Air ForceASSET program in the 1960s, which tested the heatshield design for the X-20 Dyna-Soar. On 16 March 1983[2]: 207 a Royal Australian Air ForceP-3 Orion reconnaissance aircraft captured the first Western images of the craft as it was recovered by a Soviet ship near the Cocos Islands.[3]
Flights
Seven BOR were built, and four confirmed flights took place:[4][5]
Cosmos-1374 – 4 June 1982 – BOR4 nº404 – orbital flight, splashed down into the Indian Ocean. Orbit: 158 x 204km. Inclination: 50.7 degrees. Weight: possibly about 1 tonne. Number of orbits: 1.[2]: 207
Cosmos-1445 – 15 March 1983 – BOR4 nº403 – orbital flight, splashed down into the Indian Ocean.
Cosmos-1517 – 27 December 1983 – BOR4 nº405 – orbital flight, splashed down into the Black Sea.
Cosmos-1614 – 19 December 1984 – BOR4 nº406 – orbital flight. Orbit: 176 x 223 km. Inclination: 50.7 degrees. Weight: possibly 1 tonne. Recovered after splashed down in the Black Sea.[2]: 208
^ ab"BOR: Où les voir ?" [BOR: Where to see them?]. kosmonavtika (in French). Archived from the original on 23 January 2021. Retrieved 12 February 2016.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). CubeSats are smaller. Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).
