Editing Energia (rocket) (section)

==Proposed variants==
Three major design variants were conceptualized after the original configuration, each with vastly different payloads.

===Energia-M===
The Energia-M was an early-1990s design configuration and the smallest of the three. The number of [[Zenit rocket|boosters]] was reduced from four to two, the core stage was shortened and fitted with just one [[RD-0120]] engine. It was designed to replace the Proton rocket, but lost a 1993 competition to the [[Angara rocket]].<ref>{{Cite news|url=http://www.popularmechanics.com/space/rockets/a16319/abandoned-russian-rocket-baikonur/|title=This Immense Russian Rocket Was Abandoned For Decades|date=2015-07-06|work=Popular Mechanics|access-date=2017-05-28|language=en}}</ref><ref>{{Cite web|title=Origin of the Angara project|url=http://www.russianspaceweb.com/angara_origin.html|access-date=2021-07-15|website=www.russianspaceweb.com}}</ref>

A non-functional prototype ("structural test vehicle") of the Energia M still exists in the Dynamic Test Stand facility at [[Baikonur Cosmodrome]].<ref>{{Cite web|last=Wenz|first=John|date=2015-07-06|title=This Immense Russian Rocket Was Abandoned For Decades|url=https://www.popularmechanics.com/space/rockets/a16319/abandoned-russian-rocket-baikonur/|access-date=2021-03-24|website=Popular Mechanics|language=en-US}}</ref>

===Energia-2 (GK-175)===
Energia-2 was an evolution of the Energia studied in the 1980s. Unlike the Energia-Buran, which was planned to be semi-reusable (like the U.S. [[Space Shuttle]]), the GK-175 concept was to have allowed the recovery and reuse of all elements of the vehicle, similarly to the original, fully reusable Orbiter/Booster concept of the U.S. Shuttle.<ref name="gubanov9841">{{Cite web|url=http://www.buran.ru/htm/41-3.htm|title = Б.И.Губанов. Триумф и трагедия «Энергии» глава 41}}</ref><ref>{{Cite web|url=https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110011792.pdf|title=The Space Shuttle – NASA Technical Reports Server (NTRS)|date=2011|website=nasa.gov|archive-url=https://web.archive.org/web/20150405023618/https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110011792.pdf|archive-date=5 April 2015}}</ref> The Energia-2 core as proposed would be capable of re-entering and gliding to a landing.<ref name="gubanov9841" />

===Vulkan===
The final never-built design concept was also the largest. With eight Zenit booster rockets and an Energia-M core as the upper stage, the Vulkan (which shared the name with another Soviet heavy lift rocket that was cancelled years earlier) configuration was initially projected to launch up to 200&nbsp;metric tonnes into 200&nbsp;km orbit with inclination 50.7°.<ref name="gubanov9838">{{cite book |last1=Gubanov |first1=Boris |title=Триум и трагедия "Энергии" |trans-title=Energia Triumph and Tragedy |date=1998 |location=Nizhny Novgorod |url=https://www.buran.ru/htm/gubanov3.htm |language=ru |chapter=38. Перспективный ряд ракет-носителей |trans-chapter=38. Perspective launch vehicles |publisher=NIER }}</ref>

The development of the Vulkan and the refurbishment of Universal Test Stand and Launch Pad at site 250 for its launches was in progress between 1990–1993 and abandoned soon after due to a lack of funds and the collapse of the Soviet Union.<ref>{{cite book
  |last=Godwin
  |first=Robert
  |title=Russian Spacecraft
  |publisher=[[Apogee Books]]
  |series = Space Pocket Reference Guides
  |year=2006
  |isbn=1-894959-39-6
  |pages=59 }}
</ref>