science

Progress M-21

Progress M-21 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 Progress M-21 rather than just read about it. In short: Progress M-21 (Russian: Прогресс M-21) was a Russian unmanned Progress cargo spacecraft, which was launched in January 1994 to resupply the Mir space station. Launch Progress M-21 launched on 28 January 1994 from the Baikonur Cosmodrome in Kazakhstan.

Key takeaways

Progress M-21 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Progress M-21 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Progress M-21 from memory before moving on to harder problems.

Reference excerpt

Progress M-21 (Russian: Прогресс M-21) was a Russian unmanned Progress cargo spacecraft, which was launched in January 1994 to resupply the Mir space station.

Launch Progress M-21 launched on 28 January 1994 from the Baikonur Cosmodrome in Kazakhstan. It used a Soyuz-U rocket.

Docking Progress M-21 docked with the aft port of the Kvant-1 module of Mir on 30 January 1994 at 03:56:13 UTC, and was undocked on 23 March 1994 at 01:20:29 UTC.

Decay It remained in orbit until 23 March 1994, when it was deorbited. The deorbit burn occurred at 04:23 UTC, and the mission ended at 05:13 UTC.

Illustrations

Worked examples

Example 1 — a first encounter with Progress M-21

Start with the simplest possible case. Write down what Progress M-21 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 Progress M-21 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 Progress M-21 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 Progress M-21

In research: Progress M-21 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 Progress M-21 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: Progress M-21 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1994 in Kazakhstan, Cargo spaceflights to Mir, Progress (spacecraft) missions, so understanding it makes those chapters shorter.
In everyday life: Look for Progress M-21 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 Progress M-21 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Progress M-21 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 Progress M-21 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Progress M-21 in simple terms?

Progress M-21 (Russian: Прогресс M-21) was a Russian unmanned Progress cargo spacecraft, which was launched in January 1994 to resupply the Mir space station. Launch Progress M-21 launched on 28 January 1994 from the Baikonur Cosmodrome in Kazakhstan.

Why does Progress M-21 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 Progress M-21?

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 Progress M-21.