Soyuz 7K-L1

Soyuz 7K-L1
Soyuz 7K-L1 (Zond) circumlunar spacecraft
Description
Role:	Carry cosmonauts around the Moon and back to Earth.
Crew:	2
Dimensions
Height:		4.88 m
Diameter:		2.72 m
Volume:		4 m³
Performance
Endurance:	7 days

The Soyuz 7K-L1 (also mentioned just as L1) spacecraft was designed to launch men from the Earth to circle the Moon without going into lunar orbit in the context of the Soviet manned moon-flyby program in Moon race. It was based on the Soyuz 7K-OK with several components stripped out to reduce the vehicle weight. The most notable modifications included the removal of the orbital module (providing extra space for living quarters or equipment) and a reserve parachute. Spacecraft was capable of carrying 2 cosmonauts. In the beginning there were serious reliability problems with both the new Proton rocket and the similar new Soyuz spacecraft.

Soviet space program conspiracy accusations suppose that Yuri Gagarin, first cosmonaut (astronaut) and head of Soviet "moon" team of cosmonauts, died during the alleged unsuccessfull first manned flight around Moon onboard Zond 4 at 2-7 March 1968, not in the officially announced air crash of 27 March 1968. But after 4 unsuccessful unmanned test starts (see below), at that time the L1 spacecraft was not ready for manned missions. The mission of 2-7 March really was the first flight of the L1 spacecraft under the open designation "Zond".

After the successful US Apollo 8 manned flight around Moon, the Soviet manned moon-flyby missions lost political motivation. The first manned flight of the L1/Zond spacecraft with Alexey Leonov and Valery Bykovsky planned for the end of 1968 into 1969 was cancelled.

All L1/Zond spacecraft made only unmanned automatic flights from 1967-1970, from (Zond 4 to Zond 8), and four of these five Zond flights suffered malfunctions that would have injured or killed any crew.

Test flights conducted around the Moon showed problems during re-entry. One direct descent re-entry was performed on a steep ballistic trajectory with deceleration of up to 20 Gs and splashed down in the Indian Ocean. Three others performed a maneuver known as "skip reentry" to shed velocity. One of those also performed an unsafe (for humans) descent of up to 20 Gs of deceleration, the other suffered main parachute failure, and only one flight - Zond 7 - would have been completely safe for cosmonauts.

Instrumentation flown on these missions gathered data on micrometeor flux, solar and cosmic rays, magnetic fields, radio emissions, and solar wind. Many photographs were taken and biological payloads were also flown. Zond 5 was the first spacecraft to carry a group of terrestrial creatures (tortoises being the most evolved) on a circumlunar flight and return relatively safely to Earth. Zond 5 splashed down in the Indian Ocean after descending steeply with a 20 G deceleration rate. Although unsafe for humans these high Gs apparently didn't affect the tortoises' health, and they were reportedly able to breed afterwards.

Along with the remaining 7K-L1s, the Soviet moon-flyby program was closed in 1970 without the achivement of its manned primary goal. The intended manned use of L1/Zond spacecraft was documented in official Soviet sources at first time but from 1968 until 1989 this and the moon-landing N1-L3 programs were classified and the Soviet government denied the existence of both.

Planned schedule

As of 1967, the Soyuz 7K-L1 launch schedule was:

Mission

2P -Develop Block D stage -Feb or Mar 67

3P -same -Mar 67

4L -Unmanned lunar flyby -May 67 (actually launched on September 27, 1967, booster failure)

5L -Unmanned lunar flyby -Jun 67 (actually launched on November 22, 1967, booster failure)

6L -Manned lunar flyby -Jun or Jul 67

7L&8L -Manned lunar flybys -Aug 67 (7L actually launched on April 23, 1968 as Zond 1968A, booster failure; 8L actually launched on July 21, 1968, booster explosion)

9L&10L -Manned lunar flybys -Sep 67 (10L planned to launch as Zond 9, cancelled)

11L&12L -Manned lunar flybys -Oct 67

13L -Reserve spacecraft (actually launched on January 20, 1969 as Zond 1969A, booster failure;)

In July 1968 it was proposed that L1 spacecraft would be launched every month, and the first manned mission would be in December 1968 or January 1969 after 3-4 successful unmanned flights.

In December 1969 dates for three manned L1 missions were set to March, May, and July 1969.

Finally, in September 1969 one manned L1 mission was formally set for April 1970.

Built spacecraft

Fifteen Soyuz 7K-L1 were built.

• s/n 1 - prototype not equipped with heat shield, intended to perfect orbital operation of the spacecraft without recovery of the capsule.
• s/n 2 - prototype not equipped with heat shield, intended to perfect orbital operation of the spacecraft without recovery of the capsule.
• s/n 3 -
• s/n 4 - launched on September 27, 1967, booster failure
• s/n 5 - launched on November 22, 1967, booster failure
• s/n 6 -
• s/n 7 - launched on April 23, 1968 as Zond 1968A, destroyed
• s/n 8 - launched on July 21, 1968, destroyed
• s/n 9 -
• s/n 10 - planned to launch as Zond 9, cancelled
• s/n 11 - launched as Zond 7
• s/n 12 - launched on November 10, 1968 as Zond 6, returned to Earth on November 17, 1968
• s/n 13 - launched on January 20, 1969 as Zond 1969A, failure, capsule recovered.
• s/n 14 - launched on October 20, 1970 as Zond 8, returned to Earth on October 27, 1970
• s/n 15 - planned to launch as Zond 10, cancelled

Test missions

Main article: Moon Race § Soviet circumlunar loop flights (1967–1970)

• Cosmos 146
  • Launched March 10, 1967
  • Prototype Soyuz 7K-L1P launched by Proton into planned highly elliptical earth orbit.
• Cosmos 154
  • Launched April 8, 1967
  • Prototype Soyuz 7K-L1P launched by Proton and failed into planned translunar trajectory.
• Zond 1967A (Soyuz 7K-L1 s/n 4L)
  • Launched September 27, 1967
  • First stage -1 RD-253 failed, resulting at T+67 sec in deviation from flight path.
• Zond 1967B (Soyuz 7K-L1 s/n 5L)
  • Launched November 22, 1967
  • Second stage - 1 x RD-0210 failure, shutoff of stage 4 seconds after ignition. Launcher crashed downrange.
• Zond 4
  • Launched March 2, 1968
  • Study of remote regions of circumterrestrial space, development of new on-board systems and units of space stations.
  • Returned to Earth March 7, 1968 - Self destruct system automatically blew up the capsule at 10 to 15 km altitude, 180–200 km off the African coast at Guinea.
• Zond 1968A (Soyuz 7K-L1 s/n 7L)
  • Launched April 23, 1968
  • Second stage failed 260 seconds after launch.
  • Attempted Lunar flyby
• Zond 1968B (Zond 7K-L1 s/n 8L)
  • Launched July 21, 1968
  • Block D stage exploded on pad, killing three people.
• Zond 5
  • Launched September 15, 1968
  • Circumlunar September 18, 1968
  • Returned to Earth September 21, 1968
• Zond 6 (Soyuz 7K-L1 s/n 12)
  • Launched November 10, 1968
  • Circumlunar November 14, 1968
  • Returned to Earth November 17, 1968
• Zond 1969A (Soyuz 7K-L1 s/n 13L)
  • Launched January 20, 1969
  • Stage two shutdown 25 seconds early. Automatic flight abort. Capsule was safely recovered.
  • Attempted Lunar flyby
• Zond L1S-1
  • Launched February 21, 1969
  • First stage failure. Capsule escape system fired 70 seconds after launch. Capsule was recovered.
  • Attempted Lunar orbiter and N1 rocket test
• Zond L1S-2
  • Launched July 3, 1969
  • First stage failure. Zond capsule was recovered.
  • Attempted Lunar orbiter and N1 rocket test
• Zond 7
  • Launched August 7, 1969
  • Lunar flyby August 11, 1969
  • Returned to Earth August 14, 1969
• Zond 8 (Soyuz 7K-L1 s/n 14)
  • Launched October 20, 1970
  • Lunar flyby October 24, 1970
  • Returned to Earth October 27, 1970
• Zond 9 (Soyuz 7K-L1 s/n 10L)
  • Planned but canceled
• Zond 10 (Soyuz 7K-L1 s/n 15L)
  • Planned but canceled

External links

• Very detailed information about the Soyuz 7K-L1 used in Zond 4-8
• Detailed 7K-L1 pictures
• Radios in Zond spacecraft
• Space mission timeline
• Exploring the Moon: the Zond Missions