The Mikoyan-Gurevich MiG-105, part of the Spiral program, was a crewed test vehicle to explore low-speed handling and landing. It was a visible result of a

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

project to create an orbital

spaceplane A spaceplane is a vehicle that can flight, fly and gliding flight, glide as an aircraft in Earth's atmosphere and function as a spacecraft in outer space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Orbit ...

. The MiG 105 was nicknamed "Lapot" (, or

bast shoe Bast shoes are shoes made primarily from bast—fiber taken from the bark of trees, such as linden. They are a kind of basket, woven and fitted to the shape of a foot. Bast shoes are a traditional footwear of the forest areas of Northeaster ...

; the word is also used as a slang for "

shoe A shoe is an item of footwear intended to protect and comfort the human foot. Though the human foot can adapt to varied terrains and climate conditions, it is vulnerable, and shoes provide protection. Form was originally tied to function, but ...

"), for the shape of its nose.

Development

The program was also known as the Experimental Passenger Orbital Aircraft (EPOS). Work on this project began in 1965, with the project being halted in 1969, only to be restarted in 1974 in response to the U.S.

Space Shuttle Program The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its ...

. The test vehicle made its first subsonic free-flight test in 1976, taking off under its own power from an old airstrip near Moscow. Flight tests, totaling eight in all, continued sporadically until 1978. The actual space plane project was cancelled when the decision was made to instead proceed with the Buran project. The MiG test vehicle itself still exists and is currently on display at the Monino Air Force Museum in Russia.

Spiral concept

* Soviet engineers opted for a midair launch scheme for Spiral. Known as "50 / 50", the idea was that the spaceplane and a liquid fuel booster stage would be launched at high altitude from the back of a custom-built

hypersonic In aerodynamics, a hypersonic speed is one that exceeds five times the speed of sound, often stated as starting at speeds of Mach 5 and above. The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since i ...

jet. The mothership was to have been built by the

Tupolev Design Bureau Tupolev ( rus, Туполев, , ˈtupəlʲɪf), officially United Aircraft Company Tupolev - Public Joint Stock Company, is a Russian aerospace and defence company headquartered in Basmanny District, Moscow. UAC Tupolev is successor to the Sov ...

(OKB-156) and utilize many of the same technologies developed for the

Tu-144 The Tupolev Tu-144 (; NATO reporting name: Charger) is a Soviet supersonic passenger airliner designed by Tupolev in operation from 1968 to 1999. The Tu-144 was the world's first commercial supersonic transport aircraft with its prototype's ma ...

supersonic transport The ogive.html" ;"title="Concorde supersonic transport had an ogive">ogival delta wing, a slender fuselage and four underslung Rolls-Royce/Snecma Olympus 593 engines. file:Tu-144.jpg, The Tupolev Tu-144 was the first SST to enter service and th ...

and the

Sukhoi T-4 The Sukhoi T-4, or "Aircraft 100", or "Project 100", or "Sotka" is a Soviet high-speed reconnaissance, anti-ship and strategic bomber aircraft that did not proceed beyond the prototype stage. It is sometimes called the Su-100. Design and develo ...

Mach 3 bomber. It was never built. * Spiral was a conventional

delta wing A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (letter), delta (Δ). Although long studied, the delta wing did not find significant practical applications unti ...

that featured innovative variable- dihedral wings. During launch and reentry, these were folded upward at 60 degrees. After dropping to subsonic speeds post-reentry, the pilot lowered the wings into the horizontal position, giving the spaceplane better re-entry and flight characteristics. * Spiral was built to allow for a powered landing and go-around maneuver in case of a missed landing approach. An air intake for a single Kolesov turbojet was mounted beneath the central vertical stabilizer. This was protected during launch and re-entry by a clamshell door which opened at subsonic speeds. * Spiral was to have been protected by what Soviet engineers termed "scale-plate armour": niobium alloy VN5AP and

molybdenum disilicide Molybdenum disilicide (MoSi2, or molybdenum silicide), an intermetallic compound, a silicide of molybdenum, is a refractory ceramic with primary use in heating elements. It has moderate density, melting point 2030 °C, and is electrically ...

plated steel plates mounted on articulated ceramic bearings to allow for

thermal expansion Thermal expansion is the tendency of matter to increase in length, area, or volume, changing its size and density, in response to an increase in temperature (usually excluding phase transitions). Substances usually contract with decreasing temp ...

during reentry. Several BOR (Russian acronym for Unpiloted Orbital Rocketplane) craft were flown to test this concept. * In the event of a booster explosion or in-flight emergency, the crew compartment of Spiral was designed to separate from the rest of the vehicle and parachute to earth like a conventional ballistic capsule; this could be done at any point in the flight. * Spiral was intended to carry only its pilot. * Spiral was designed to land on skids, which deployed from a set of doors on the sides of the fuselage just above and ahead of the wings.

BOR reentry test vehicles

Another spacecraft to use the Spiral design was the ''БОР'' (, , "Unpiloted Orbital Rocketplane") series, uncrewed sub-scale reentry test vehicles. American analogs were the

X-23 PRIME The Martin X-23A PRIME (Precision Reentry Including Maneuvering reEntry) (SV-5D) is a small lifting-body re-entry vehicle tested by the United States Air Force in the mid-1960s. Unlike ASSET, primarily used for structural and heating research, ...

and

ASSET In financial accounting, an asset is any resource owned or controlled by a business or an economic entity. It is anything (tangible or intangible) that can be used to produce positive economic value. Assets represent value of ownership that can b ...

. Several of these craft have been preserved in aerospace museums around the world.

Specifications (MiG 105-11)

References

External links