science

Soyuz 23

Soyuz 23 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 23 rather than just read about it. In short: Soyuz 23 (Russian: Союз 23, Union 23) was an October 1976, Soviet crewed space flight, the second to the Salyut 5 space station. Cosmonauts Vyacheslav Zudov and Valery Rozhdestvensky arrived at the station, but an equipment malfunction did not allow docking and the mission had to be aborted.

Key takeaways

Soyuz 23 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 23 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Soyuz 23 from memory before moving on to harder problems.

Reference excerpt

Soyuz 23 (Russian: Союз 23, Union 23) was an October 1976, Soviet crewed space flight, the second to the Salyut 5 space station. Cosmonauts Vyacheslav Zudov and Valery Rozhdestvensky arrived at the station, but an equipment malfunction did not allow docking and the mission had to be aborted. The crew returned to Earth, but landed on partially frozen Lake Tengiz, the first crewed splashdown in the Soviet space program. While there was no concern about any immediate threat to the crew, the capsule sank under the surface of the frozen lake, and recovery took nine hours owing to fog and other adverse conditions. The landing is the only example of an unintentional splashdown of a crewed spacecraft.

Crew

Backup crew

Reserve crew

Mission highlights Soyuz 23 was launched 14 October 1976 with an estimated 73- to 85-day mission planned aboard the orbiting Salyut 5 space station. Other sources suggest a 17- to 24-day mission was a more likely intention. It was the first visit to the station after the sudden termination of the Soyuz 21 mission in August 1976. However, on 15 October 1976, during the automatic approach phase, the automatic docking system malfunctioned before the craft was within 100 metres of the station. Crews were trained for a manual dock, but not for a manual approach. The mission, accordingly, had to be abandoned. The craft had only two days of battery power, so systems were powered off, including the radio, to conserve power. The day's landing opportunity had already passed, so they had to wait for the next day's landing opportunity near the Baikonur Cosmodrome. On 16 October 1976, Soyuz 23 returned to Earth and landed at 17:45:53 UTC, but weather conditions were poor and the cosmonauts experienced an unusual recovery. They landed on a freezing Lake Tengiz (average depth 2.5 m, max depth 6.7 m), at 8 km from shore, in the middle of a blizzard, with fog and temperatures at −22 °C. It was the first water landing by a Soviet crew. The capsule was designed to land in any conditions, even in a body of water, so the only concern was the increased difficulty in finding the capsule and crew. The parachute quickly sank beneath water and dragged the capsule and its crew beneath the surface; in addition, an electrical short, caused by the water impact, caused the reserve parachute to accidentally deploy. The capsule cooled in the freezing water, and the cosmonauts removed their pressure suits and donned their normal flight suits, expecting a quick rescue. The parachutes became waterlogged and pulled the capsule onto its side, preventing the hatch from being opened. The transmission antennas were also under water, so the crew could not communicate with rescue teams. The capsule's beacons could not be seen in the heavy fog, and rubber rafts used to try to reach them were blocked by ice and sludge. Amphibious vehicles were airlifted to the vicinity, but could not reach the capsule owing to bogs surrounding the lake. Accordingly, the rescue was called off until dawn. The cosmonauts were safe, but they were low on power, so they were forced to shut down everything but a small interior light. The next morning, frogmen were dropped in by helicopters and attached flotation devices to the Soyuz craft. The capsule was too heavy to be lifted by the helicopter, so it was dragged to shore. The recovery operation had taken nine hours. No attempt was made to open the hatch as the recovery crews assumed the cosmonauts were dead, so they called for a special team to remove their bodies. Eventually, eleven hours after splashdown, the capsule was opened, and the crew was found unconscious due to CO2 accumulation in the submerged and powered down vessel. The cosmonauts were rescued, if badly chilled (the interior of the descent module was coated with frost). Press releases by Soviet news agency TASS announced that there had been a water landing and that the cosmonauts were recovered safely, but made no mention of the rescue operation involved and the details of it were not revealed until the era of glasnost a decade later.

Mission parameters Mass: 6,750 kg (14,880 lb) Perigee: 243.0 km (151.0 mi) Apogee: 275.0 km (170.9 mi) Inclination: 51.6° Period: 89.5 minutes

Illustrations

Worked examples

Example 1 — a first encounter with Soyuz 23

Start with the simplest possible case. Write down what Soyuz 23 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 23 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 23 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 23

In research: Soyuz 23 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 23 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 23 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1976 in the Soviet Union, Crewed Soyuz missions, Human spaceflights to Salyut space stations, so understanding it makes those chapters shorter.
In everyday life: Look for Soyuz 23 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 23 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Soyuz 23 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Soyuz 23 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Soyuz 23 in simple terms?

Why does Soyuz 23 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 23?

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 23.