Mikoyan-Gurevich MiG-105

Mikoyan-Gurevich MiG-105
Company type	Experimental aircraft
Industry	Aerospace
Founded	1965
Defunct	1978
Fate	Program discontinued in favor of Buran project
Headquarters	Moscow (test flights near Moscow), Soviet Union
Products	Manned test platform for low-speed aerodynamics and landing capabilities of orbital spaceplane

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The Mikoyan-Gurevich MiG-105, developed under the Spiral initiative, served as a manned test platform to investigate low-speed aerodynamics and landing capabilities. This vehicle represented a tangible outcome of a Soviet endeavor aimed at creating an orbital spaceplane. The MiG 105 earned the informal moniker "Lapot" (Russian: лапоть, translating to bast shoe and colloquially meaning "shoe") due to the distinctive shape of its nose.

Development

Also referred to as the Experimental Passenger Orbital Aircraft (EPOS), this program commenced in 1965 but was suspended in 1969. It was subsequently revived in 1974 as a countermeasure to the U.S. Space Shuttle Program. The test craft conducted its inaugural subsonic free-flight trial in 1976, launching independently from a former airfield near Moscow. A total of eight flight tests were carried out intermittently until 1978. The broader spaceplane initiative was ultimately discontinued in favor of advancing the Buran project. The MiG test vehicle remains preserved and is exhibited at Russia’s Monino Air Force Museum.

Spiral concept

The Spiral project employed a midair launch approach known as "50 / 50," where the spaceplane, coupled with a liquid-fueled booster stage, would be released at high altitude from a hypersonic carrier aircraft. This mothership was planned to be developed by the Tupolev Design Bureau (OKB-156), incorporating technologies derived from the Tu-144 supersonic transport and the Sukhoi T-4 Mach 3 bomber. However, this carrier aircraft was never constructed.
Featuring a traditional delta wing design, Spiral incorporated innovative variable-dihedral wings that could fold upward by 60 degrees during launch and reentry phases. Upon deceleration to subsonic speeds after reentry, the pilot would lower the wings into a horizontal alignment to enhance flight and reentry performance.
Spiral was engineered for powered landings with the capability for go-around maneuvers if necessary. A single Kolesov turbojet engine intake was positioned beneath the central vertical stabilizer, protected during launch and reentry by clamshell doors that opened only at subsonic velocities.
Thermal protection for Spiral relied on what Soviet engineers termed "scale-plate armour," consisting of steel plates coated with niobium alloy VN5AP and molybdenum disilicide, mounted on articulated ceramic bearings to accommodate thermal expansion during reentry. This concept was validated through several BOR (Russian acronym for Unpiloted Orbital Rocketplane) test vehicles.
In case of booster malfunction or other emergencies during flight, Spiral's crew compartment was designed to detach from the main vehicle and descend via parachute, functioning similarly to a standard ballistic escape capsule; this separation could occur at any stage of flight.
The craft was intended to be operated by a single pilot exclusively.
For landing, Spiral utilized skids that extended from doors located on both sides of the fuselage just ahead of and above the wings.

BOR reentry test vehicles

The БОР (Russian: Беспилотный Орбитальный Ракетоплан, Bespilotnyi Orbital'nyi Raketoplan, meaning "Unmanned Orbital Rocketplane") series consisted of uncrewed, scaled-down reentry test vehicles based on the Spiral design. Comparable American projects include the X-23 PRIME and ASSET. Multiple examples of these vehicles are exhibited in aerospace museums internationally.

Image	Model	Launch Date	Purpose	Present Location
	BOR-1	15.07.1969	Experimental flight test, a one-third scale prototype. Disintegrated in the atmosphere at approximately 60–70 km altitude traveling at roughly 8,000 mph (12,900 km/h). Released from an altitude of 328,083 ft (100 km) by a 11K65 rocket	Destroyed as expected.
File:BOR-2.jpg	BOR-2	1969–1972	Sub-scale Spiral spaceplane model with four launches conducted.	Preserved at NPO Molniya, Moscow
	BOR-3	1973–1974	Sub-scale Spiral spaceplane model with two launches. 1. Nose fairings were destroyed shortly after launch around five kilometers altitude (speed 0.94 Mach). 2. Completed full flight profile but crashed during landing due to parachute malfunction.	Crashed.
File:BOR-4S.jpg	BOR-4	1980–1984	Sub-scale Spiral spaceplane with four confirmed launches and two additional unverified flights.	Displayed at NPO Molniya, Moscow
File:BOR-5 Oberseite.JPG	BOR-5	1984–1988	Flight testing of an experimental sub-scale base model differing in shape from the Spiral spaceplane; data contributed to the Buran program. Five launches conducted.	Exhibited at Technik Museum Speyer, Germany and Museum in Monino, Russia
File:BOR-6.jpg	BOR-6		Sub-scale Spiral spaceplane model.	Held at NPO Molniya, Moscow

Specifications (MiG 105-11)

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References

External links

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