R-7 (rocket family) explained

The R-7 (ru|Р-7) rocket family is a series of launch vehicles descended from the Soviet R-7 Semyorka, developed in the 1950s as the world's first intercontinental ballistic missile (ICBM). While the R-7 proved impractical as a weapon, it became a cornerstone of the Soviet and subsequent Russian space programs. Over time, its design was largely standardized into the Soyuz rocket, which continues to operate in its modernized form, the Soyuz-2. More R-7 rockets have been launched than any other family of large rockets.

Background

The R-7, developed by OKB-1 in Kaliningrad, a Soviet design bureau led by rocket pioneer Sergey Korolyov, was the world's first intercontinental ballistic missile (ICBM). Initially designed to deliver nuclear warheads to American targets, it was first successfully tested on 21 August 1957.

The R-7's basic design comprises a central core stage (Block A) and four strap-on boosters (Block B, V, G, and D), fueled by refined kerosene (RG-1), mixed with cryogenic liquid oxygen (LOX) as the oxidizer. Its stage numbering differs from conventional rockets: the boosters are considered the first stage, and the core stage is the second, though they ignite simultaneously at liftoff. The boosters burn for approximately two minutes before jettisoning, while the core stage continues to burn for about five minutes.

The R-7's impracticality as a weapon became quickly apparent. Its huge launch complexes were vulnerable to attack, the 10 hours it took to prepare for launch hindered its operational readiness, and its reliance on a cryogenic oxidizer meant that it could not be left on alert for more than an hour.[1] [2]

However, due to the weight of Soviet nuclear warheads, the R-7 possessed a significantly greater payload capacity than early U.S. ICBMs. This advantage made the R-7 suitable for space launch missions, giving the Soviet Union a substantial head start in the Space Race. An unmodified R-7 launched Sputnik 1, the world's first artificial satellite. With the addition of upper stages, the R-7 spawned numerous variants, each optimized for specific missions. The Vostok variant carried the first human into orbit, Yuri Gagarin. Other variants, such as Luna, Voshkod, and Molniya, were used for lunar probes, reconnaissance satellites, and communications satellites. Later modifications were standardized around multipurpose Soyuz design, first used in 1966. Its modernized version, the Soyuz-2, continues to serve as a workhorse for the Russian space program.[3]

Production of the R-7 family moved to the Progress Aviation Factory in Samara, Russia, in 1959. Over time, complete responsibility for the entire R-7 family shifted from the main OKB-1 office in Kaliningrad to Samara. The design facilities in Samara evolved from an OKB-1 subsidiary into the independent Central Specialized Design Bureau (TsSKB) in 1974. TsSKB and the Progress factory collaborated on the design, development, and production of Soyuz rockets. In 1996, TsSKB and the Progress factory merged to form a single company, Rocket and Space Centre "Progress" (RKTs Progress).

R-7 rockets are launched from the Baikonur Cosmodrome, Plesetsk Cosmodrome, and Vostochny Cosmodrome and were previously launched from the Guiana Space Centre between 2011 and 2022.

Summary of variants

All the R-7 family rockets are listed here by date of introduction. Most of the early R-7 variants have been retired. Active versions (as of 2022) are shown in green.

NameGRAU
index
Function
Stages
Maiden flightFinal flightLaunchesRemarks
TotalSuccessFailure
R-7 Semyorka8K71ICBM215 May 195727 February 196127189World's first ICBM
Sputnik-PS8K71PSCarrier rocket24 October 19573 November 1957220World's first carrier rocket
Launched Sputnik 1 and Sputnik 2
Sputnik8A91Carrier rocket227 April 195815 May 1958211Launched Sputnik 3
Luna8K72Carrier rocket323 September 195816 April 1960927
R-7A Semyorka8K74ICBM223 December 195925 July 196721183The only operational ICBM version. Improved range and guidance system. Only 6 launch positions were available. Used as a base for 11A57 and later mods
Vostok-L8K72LCarrier rocket315 May 19601 December 1960431Variant of Luna, used to launch prototype Vostok spacecraft
Molniya8K78Carrier rocket420 January 19603 December 1965261214Designed to send payloads out of LEO
Vostok-K8K72KCarrier rocket322 December 196010 July 196413112Used for crewed Vostok missions
First rocket to launch a man into space
Molniya-L8K78LCarrier rocket4Unbuilt
Vostok-28A92Carrier rocket31 June 196212 May 196745405Used for launching Zenit reconnaissance satellites throughout the 1960s
Polyot11A59Carrier rocket21 November 196312 April 1964220
Voskhod11A57Carrier rocket316 November 196329 June 197630027723Launched crewed Voskhod 1 and Voskhod 2 missions
Molniya-M8K78MCarrier rocket419 February 196430 September 2010[4] 29727621Improved version of Molniya
Vostok-2M8A92MCarrier rocket328 August 196429 August 199194922Modified version for launching Meteor weather satellites into higher orbits
Soyuz/Vostok11A510Carrier rocket427 December 196520 July 1966220Launched with prototype US-A satellites
Soyuz11A511Carrier rocket328 November 196624 May 197530282Used for crewed Soyuz launches.
Soyuz-B11K55Carrier rocket3Unbuilt
Soyuz-V11K56Carrier rocket3Unbuilt
Soyuz-R11A514Carrier rocket3Unbuilt
Soyuz-L11A511LCarrier rocket324 November 197012 August 1971330Created to test the LK lunar lander in LEO
Soyuz-M11A511MCarrier rocket327 December 197131 March 1976880Built to launch crewed Soyuz 7K-VI spacecraft, eventually used to launch reconnaissance satellites
Soyuz-U11A511UCarrier rocket3 or 418 May 197322 February 201778676522[5] Single most launched carrier rocket ever built
Used for crewed Soyuz launches.
Soyuz-U211A511U2Carrier rocket323 December 19823 September 199572720Used for crewed Soyuz launches.
Soyuz-FG11A511U-FGCarrier rocket3 or 420 May 200125 September 201970691Used for crewed Soyuz launches.
Soyuz-2.1a / Soyuz-ST-A14A14ACarrier rocket3 or 48 November 2004Active75722+1pUsed for crewed Soyuz launches from Soyuz MS-16 on 9 April 2020. In August 2019 the booster lofted the uncrewed Soyuz MS-14 into orbit in order to test the spacecraft on the new rocket.
Soyuz-2.1b / Soyuz-ST-B14A14BCarrier rocket3 or 427 December 2006Active90872+1p
Soyuz-2.1v14A15Carrier rocket328 December 2013Active12111p1st stage uses a completely new design utilizing surplus NK-33 engines from the Moon N-1 launcher and no boosters.

Korolev Cross

The Korolev Cross is a visual phenomenon observed in the smoke plumes of the R-7 series rockets during separation of the four liquid-fueled booster rockets attached to the core stage.[6] As the boosters fall away from the rocket, they pitch over symmetrically due to aerodynamic forces acting upon them, forming a cross-like shape behind the rocket. The effect is named after Sergei Korolev, the designer of the R-7 rocket. When the rocket is launched into clear skies, the effect can be seen from the ground at the launch site.

See also

References

External links

Notes and References

  1. Web site: R-7 History . 26 December 2023 . World Space Flight.
  2. Book: Siddiqi . Asif . Challenge to Apollo: the Soviet Union and the space race, 1945–1974 . 2000 . National Aeronautics and Space Administration, NASA History Div. . Washington, D.C. . 212-214 . 22 May 2022.
  3. Web site: April 2001 . Soyuz User's Manual . 28 November 2024 . . 197-201.
  4. Web site: Russia sends military satellite into space. https://web.archive.org/web/20101003123534/http://news.xinhuanet.com/english2010/world/2010-10/01/c_13537937.htm. dead. 3 October 2010. Mu. Xuequan. 1 October 2010. Xinhua. 30 September 2010.
  5. In 1983, flight Soyuz T-10a caught fire on the launch pad before the end of the countdown, so it is not counted in the list of launches; this is why adding successes and failures yields 787 launches instead of 786.
  6. NASA TV coverage of Soyuz TMA-12 launch