astronomy

Mars 7

Mars 7 is a astronomy 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 Mars 7 rather than just read about it. In short: Mars 7 (Russian: Марс-7), also known as 3MP No.51P was a Soviet spacecraft launched in 1973 to explore Mars. A 3MP bus spacecraft which comprised the final mission of the Mars programme, it consisted of a lander and a coast stage with instruments to study Mars as it flew past.

Key takeaways

Mars 7 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Mars 7 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Mars 7 from memory before moving on to harder problems.

Reference excerpt

Mars 7 (Russian: Марс-7), also known as 3MP No.51P was a Soviet spacecraft launched in 1973 to explore Mars. A 3MP bus spacecraft which comprised the final mission of the Mars programme, it consisted of a lander and a coast stage with instruments to study Mars as it flew past. Due to a malfunction, the lander failed to perform a maneuver necessary to enter the Martian atmosphere, missing the planet and remaining in heliocentric orbit along with the coast stage.

Spacecraft Mars 7 spacecraft carried an array of instruments to study Mars. The lander was equipped with a thermometer and barometer to determine the surface conditions, an accelerometer and radio altimeter for descent, and instruments to analyse the surface material including a mass spectrometer. The coast stage, or bus, carried a magnetometer, plasma traps, cosmic ray and micrometeoroid detectors, stereo antennae, and an instrument to study proton and electron fluxes from the Sun. Built by Lavochkin, Mars 7 was the second of two 3MP spacecraft launched to Mars in 1973, having been preceded by Mars 6. Two orbiters, Mars 4 and Mars 5, were launched earlier in the 1973 Mars launch window and were expected to relay data for the two landers. However, Mars 4 failed to enter orbit, and Mars 5 failed after a few days in orbit.

Launch Mars 7 was launched by a Proton-K carrier rocket with a Blok D upper stage, flying from Baikonur Cosmodrome Site 81/24. The launch occurred at 17:00:17 UTC on 9 August 1973, with the first three stages placing the spacecraft and upper stage into a low Earth parking orbit before the Blok D fired to propel Mars 7 into heliocentric orbit bound for Mars. The spacecraft performed a course correction on 16 August 1973. Mars 7's lander separated from the flyby bus on 9 March 1974. Initially, it failed to separate. However, it was eventually released to begin its descent. Due to a retrorocket failure, the probe missed the atmosphere of Mars, and, instead of landing, flew past along with the coast stage, with a closest approach of 1,300 km (810 mi). Known faults with the spacecraft's transistors were blamed for the failure, along with that of Mars 4.

See also List of missions to Mars Timeline of artificial satellites and space probes

References

Illustrations

Worked examples

Example 1 — a first encounter with Mars 7

Start with the simplest possible case. Write down what Mars 7 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 Mars 7 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 Mars 7 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 Mars 7

In research: Mars 7 appears in astronomy 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 Mars 7 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: Mars 7 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1973 in spaceflight, 1973 in the Soviet Union, 4MV, so understanding it makes those chapters shorter.
In everyday life: Look for Mars 7 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Mars 7” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Mars 7 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Mars 7 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 Mars 7 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Mars 7 in simple terms?

Why does Mars 7 matter?

Because it connects several astronomy 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 Mars 7?

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 Mars 7.