Kholod

[[File:Kholod.jpg|thumb|Prototype Kholod]]

'''Kholod''' (Холод) is an experimental Russian rocket project. The [[Hypersonic flight|hypersonic]] [[rocket]] uses a [[scramjet]] engine and was created to exceed [[Mach Number|Mach]] 6+ The prototype consists of a [[Soyuz (rocket family)|Soyuz TMKB]] with [[liquid hydrogen]] and modified fillings from the [[SA-5 Gammon]] missiles. The entire rocket, including the four [[booster rocket]]s, is {{convert|12|m}} long and {{convert|750|mm}} in diameter.<ref>{{Cite web|url=http://www.russianspaceweb.com/kholod.html|title=Kholod project|website=www.russianspaceweb.com}}</ref><ref>Roudakov, A.S., Y. Schickhman, V. Semenov, Ph. Novelli, and O. Fourt, "Flight Testing an Axisymmetric Scramjet: Russian Recent Advances," 44th Congress of the International Astronautical Federation, Oct. 16– 22, 1993, Graz, Austria</ref><ref>{{Cite web|url=http://xplanes.free.fr/stato/stato-17.html|title=Prototypes.com/La saga des statoréacteurs/XVII. Les records de vitesse|website=xplanes.free.fr}}</ref><ref>{{Cite web|url=https://www.siliconrepublic.com/discovery/supersonic-scramjet-to-go-up-for-auction-in-london|title=Supersonic scramjet to go up for auction in London|first=Colm|last=Gorey|date=July 22, 2014|website=Silicon Republic}}</ref><ref>{{Cite web|url=https://browncarguy.com/2014/07/22/used-rocket-for-sale-two-careless-owners/|title=Used rocket for sale, two careless owners|first=Shahzad|last=Sheikh|date=July 21, 2014}}</ref><ref name=BBC2015>{{cite web|title='Cool' Russian rocket installed in Wiltshire garden|url=https://www.bbc.co.uk/news/uk-england-wiltshire-32842534|website=[[BBC News]]|publisher=[[BBC]]|accessdate=26 May 2015}}</ref> The project led to other Russian hypersonic rockets like the [[GLL-8 (Gll-VK) Igla|Igla]] rocket craft and the [[Yu-71]] [[boost-glide]] warhead.

The Kholod became part of a joint [[Baranov Central Institute of Aviation Motor Development|CIAM]]/[[NASA]] project to enhance the fundamental understanding of variable geometry ram/scramjet hybrids beginning in the 1990s.<ref>Roudakov, Alexander S., Semenov, Vyacheslav L., Hicks, John W. "Recent Flight Test Results of the Joint CIAM-NASA Mach 6.5 Scramjet Flight Program." NASA Technical Reports Server, August 8, 2018. Accessed March 3, 2021. https://ntrs.nasa.gov/citations/19980137604.</ref> These tests resulted in successful flights from [[Sary Shagan]] test range in central [[Kazakhstan]] 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]]. 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 sensor|pressure transducers]] and 58 [[thermocouple]]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]] named "FeCrAl". The new alloy consisted of [[steel]] (Fe), [[chromium]] (Cr), and [[aluminum]] (Al) that was then covered with chromium-[[nickel]] spray; this was a major improvement over the use of the [[stainless steel]] alloy EP-666.

The information obtained by the Hypersonic Flying Laboratory enabled researchers to begin designing the next generation of ramjets and scramjets.<ref>Roudakov, Alexander S., Semenov, Vyacheslav L., Hicks, John W. "Recent Flight Test Results of the Joint CIAM-NASA Mach 6.5 Scramjet Flight Program." NASA Technical Reports Server, August 8, 2018. Accessed March 3, 2021. https://ntrs.nasa.gov/citations/19980137604.</ref>

Russia 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 [[NASA X-43|X-43]] to further refine the mechanics of scramjets and to develop control surfaces to enable maneuverability at hypersonic speeds.<ref>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.</ref>

== References == <references/>

{{DEFAULTSORT:Kholod (scramjet)}} [[Category:Space program of the Soviet Union]] [[Category:Soviet inventions]] [[Category:Hypersonic aircraft]]