Kholod (Холод) is the name of an experimental Russian rocket

project A project is any undertaking, carried out individually or collaboratively and possibly involving research or design, that is carefully planned to achieve a particular goal. An alternative view sees a project managerially as a sequence of even ...

. The

hypersonic In aerodynamics, a hypersonic speed is one that exceeds 5 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 in ...

rocket A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...

uses a

scramjet A scramjet (supersonic combustion ramjet) is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully ...

engine and was created to exceed Mach 5.75. The prototype consists of a Soyuz TMKB with

liquid hydrogen Liquid hydrogen (LH2 or LH2) is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecular H2 form. To exist as a liquid, H2 must be cooled below its critical point of 33 K. However, for it to be in a fully li ...

and modified fillings from the

SA-5 Gammon The NPO Almaz S 200 ''Angara/Vega/Dubna'' ( Russian С-200 Ангара/Вега/Дубна), NATO reporting name SA-5 '' Gammon'' (initially ''Tallinn''), is a long range, high altitude surface-to-air missile (SAM) system developed by the Sov ...

missiles. The entire rocket, including the four

booster rocket A booster rocket (or engine) is either the first stage of a multistage launch vehicle, or else a shorter-burning rocket used in parallel with longer-burning sustainer rockets to augment the space vehicle's takeoff thrust and payload capability ...

s, is long and in diameter. The project led to other Russian hypersonic rockets like the Igla rocket craft and the Yu-71

boost-glide Non-ballistic atmospheric entry is a class of atmospheric entry trajectories that follow a non-ballistic trajectory by employing aerodynamic lift in the high upper atmosphere. It includes trajectories such as skip and glide. Skip is a flight tr ...

warhead. The Kholod became part of a joint CIAM/

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

project to enhance the fundamental understanding of variable geometry ram/scramjet hybrids beginning in the 1990s. These tests resulted in successful flights from

Sary Shagan Sary Shagan ( rus, Сары-Шаган; kz, Сарышаған) is an anti-ballistic missile testing range located in Kazakhstan. On 17 August 1956 the Council of Ministers of the Soviet Union authorized plans for an experimental facility for ...

test range in central

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

in 1998. The aim of the partnership was to test the Kholod’s scramjet at Mach 6.5 while recording all relevant test data both onboard and via

telemetry Telemetry is the in situ data collection, collection of measurements or other data at remote points and their automatic data transmission, transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Gr ...

. The Kholod allowed for the testing of variable hypersonic flow, ramjet/scramjet geometry, and more importantly to act as a litmus test to ensure that the data produced by ground experiments was consistent with real world testing at altitude. The Kholod contained an array of 83 pressure transducers and 58

thermocouple A thermocouple, also known as a "thermoelectrical thermometer", is an electrical device consisting of two dissimilar electrical conductors forming an electrical junction. A thermocouple produces a temperature-dependent voltage as a result of the ...

s, to monitor the effects of hypersonic flow on the leading edge and inlet. The Kholod’s sustained run of its dual mode ramjet/scramjet was primarily enabled by the development of a new

alloy An alloy is a mixture of chemical elements of which at least one is a metal. Unlike chemical compounds with metallic bases, an alloy will retain all the properties of a metal in the resulting material, such as electrical conductivity, ductility, ...

named "FeKrAl". The new alloy consisted of

steel Steel is an alloy made up of iron with added carbon to improve its strength and fracture resistance compared to other forms of iron. Many other elements may be present or added. Stainless steels that are corrosion- and oxidation-resistant ty ...

(Fe),

chromium Chromium is a chemical element with the symbol Cr and atomic number 24. It is the first element in group 6. It is a steely-grey, lustrous, hard, and brittle transition metal. Chromium metal is valued for its high corrosion resistance and hardne ...

(Kr), and

aluminum Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has ...

(Al) that was then covered with chromium-

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow to ...

spray; this was a major improvement over the use of the

stainless steel Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corros ...

alloy EP-666. The information obtained by the Hypersonic Flying Laboratory enabled researchers to begin designing the next generation of ramjets and scramjets.

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

would continue to research scramjet platforms under the ORYOL-2-1 program that focused on developing the GLL-8 Igla platform. The success of the Kholod program led to the development of NASA’s X-43 to further refine the mechanics of scramjets and to develop control surfaces to enable maneuverability at hypersonic speeds.Alexander Roudakov, Vyacheslav Semenov, Valeriy Kopchenov and John Hicks. "Future flight test plans of an axisymmetric hydrogen-fueled scramjet engine on the Hypersonic Flying Laboratory," AIAA 1996-4572. Space Plane and Hypersonic Systems and Technology Conference. November 1996. Accessed March 3, 2021. https://arc.aiaa.org/doi/10.2514/6.1996-4572.

References

{{DEFAULTSORT:Kholod (scramjet) Space program of the Soviet Union Science and technology in the Soviet Union Hypersonic aircraft