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Soyuz 9

Soyuz 9 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Soyuz 9 rather than just read about it. In short: Soyuz 9 (Russian: Союз 9, Union 9) was a Soviet crewed space flight launched in June 1970. The two-man crew of Andriyan Nikolayev and Vitaly Sevastyanov broke the five-year-old space endurance record held by Gemini 7, with their nearly 18-day flight.

Soyuz 9 — main illustration
Soyuz 9 — illustration

Key takeaways

  • Soyuz 9 belongs to science; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Soyuz 9 to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Soyuz 9 from memory before moving on to harder problems.

Reference excerpt

Soyuz 9 (Russian: Союз 9, Union 9) was a Soviet crewed space flight launched in June 1970. The two-man crew of Andriyan Nikolayev and Vitaly Sevastyanov broke the five-year-old space endurance record held by Gemini 7, with their nearly 18-day flight. The mission enabled the Salyut space station missions, investigating the effects of long-term weightlessness on crew, and evaluating the work that the cosmonauts could do in orbit, individually and as a team. It was also the last flight of the first-generation Soyuz 7K-OK spacecraft, as well as the first crewed space launch to be conducted at night. As of 2026, Soyuz 9 marks the longest crewed flight by a solo spacecraft.

Crew

Backup crew

Reserve crew

Mission The flight was primarily a preparatory run for the planned long duration space station missions. It tested, for a longer period of time than any other, the capacity of the hardware and the human crew, on the long-term exposure to space conditions and observing (both visually and photographically) geological and geographical objects, weather formations, water surfaces, and snow and ice covers. The crew conducted observations of celestial bodies and practiced astronavigation, by locking onto Vega or Canopus, and then used a sextant to measure its relation to the Earth horizon. The orbital elements were refined to three decimal places by the crew. Soyuz 9 was planned to be the first manned Soviet space mission launched during nighttime hours and it had been hoped to launch it on April 22 to commemorate the centennial of Lenin's birth but the mission took two more months to be ready. LC-1 was off-line for a year from October 1969 to October '70 as the pad was being renovated to be able to support Zenit reconnaissance satellite launches, so all R-7 vehicle launches from Baikonur during this time took place from LC-31. The pad sustained some damage during a Zenit launch on May 20 due to wind blowing around the rocket's exhaust flames and burning through cabling but repairs were quickly completed. Further delays occurred when problems were found with the spacecraft's electrical system. There was also a fault with the propellant feed system on the Blok I stage of the booster--this issue had occurred on several Zenit launches but to date not a Soyuz launch. The booster was rolled out to the pad and erected on 1 June and prelaunch preparations went smoothly. Liftoff took place at 11:00 PM Moscow time and the spacecraft was inserted into a 136x128 mile (219x206 km) orbit. The cosmonauts fired the Soyuz's engine to enter an orbit of 132x167 miles (214x269 km). Once this had been accomplished, the Soviet state media officially announced the mission and described it as a "long duration flight" although the specific duration was not mentioned. Another engine burn the night of 2 June placed Soyuz 9 in a 165x153 mile (266x247 km) orbit at a 51° inclination which was considered stable enough to last for the length of the mission. Efforts were made to make the accommodations inside Soyuz 9 comfortable for the cosmonauts' lengthy mission. They had sleeping bags inside the orbital module and a heater to prepare food with. They watched broadcasts of the 1970 World Cup on TV. A rudimentary exercise regimen was carried out so as to keep them in shape over the mission although this would prove less effective than hoped. 16 June marked fifteen days in orbit and there were concerns about the spacecraft's orbit decaying too much by 20 June thus an engine burn would have to be conducted on 18 June to raise the orbit, but medical director E. Vorobiev argued that an extra day of flight was not necessary for medical data-gathering purposes and it would be better to land while the Soyuz still had adequate propellant reserves. Ultimately it was decided to go for the original 18 day flight plan if the propellant supply could hold out. De-orbit and landing took place on 19 June at about 75 kilometers (46 miles) west of Karaganda. The cosmonauts were weaker than anticipated and had to be helped to the evacuation helicopter. Nikolayev momentarily became unconscious during the walk. Both developed a high fever and postflight medical examination found that their hearts had shrunk by as much as 20%. It was a week before they were able to walk unassisted. The lessons learned from Soyuz 9 were utilized in planning for the Salyut program, which was then in the developmental phase. Commander Nikolayev and flight engineer Sevastyanov spent 18 days in space conducting various physiological and biomedical experiments on themselves, but also investigating the social implications of prolonged spaceflight. The cosmonauts spent time in two-way TV links with their families, watched matches in the 1970 FIFA World Cup, played chess with ground control, and voted in a Soviet election. The mission set a new space endurance record and marked a shift in emphasis away from spacefarers merely being able to exist in space for the duration of a long mission (such as the Apollo flights to the Moon) to being able to live in space. The mission took an unexpected physical toll on the cosmonauts; in order to conserve attitude control gas during the lengthy stay in orbit, Soyuz 9 was placed in a spin-stabilisation mode that made Nikolayev and Sevastyanov dizzy and space sick.

Mission parameters Mass: 6,460 kg (14,240 lb) Perigee: 207.0 km (128.6 mi) Apogee: 220.0 km (136.7 mi) Inclination: 51.70° Period: 88.59 minutes

Chess game

… excerpt ends here. Continue reading the full article.

Illustrations

Soyuz 9 illustration
Soyuz 9 illustration

Worked examples

Example 1 — a first encounter with Soyuz 9

Start with the simplest possible case. Write down what Soyuz 9 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Soyuz 9 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Soyuz 9 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Soyuz 9

In research
Soyuz 9 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Soyuz 9 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Soyuz 9 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1970 in the Soviet Union, Crewed Soyuz missions, Spacecraft launched in 1970, so understanding it makes those chapters shorter.
In everyday life
Look for Soyuz 9 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Soyuz 9 in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Soyuz 9 means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Soyuz 9 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Soyuz 9 in simple terms?

Soyuz 9 (Russian: Союз 9, Union 9) was a Soviet crewed space flight launched in June 1970. The two-man crew of Andriyan Nikolayev and Vitaly Sevastyanov broke the five-year-old space endurance record held by Gemini 7, with their nearly 18-day flight.

Why does Soyuz 9 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Soyuz 9?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Soyuz 9.

Tags

  • 1970 in the Soviet Union
  • Crewed Soyuz missions
  • Spacecraft launched in 1970
  • Spacecraft which reentered in 1970

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