science

Progress MS-21

Progress MS-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 MS-21 rather than just read about it. In short: Progress MS-21 (Russian: Прогресс МC-21), Russian production No.451, identified by NASA as Progress 82P, was a Progress spaceflight launched by Roscosmos to resupply the International Space Station (ISS). It was the 174th flight of a Progress spacecraft.

Key takeaways

Progress MS-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 MS-21 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Progress MS-21 from memory before moving on to harder problems.

Reference excerpt

Progress MS-21 (Russian: Прогресс МC-21), Russian production No.451, identified by NASA as Progress 82P, was a Progress spaceflight launched by Roscosmos to resupply the International Space Station (ISS). It was the 174th flight of a Progress spacecraft.

History The Progress-MS is an uncrewed freighter based on the Progress-M featuring improved avionics. This improved variant first launched on 21 December 2015. It has the following improvements:

New external compartment that enables it to deploy satellites. Each compartment can hold up to four launch containers. First time installed on Progress MS-03. Enhanced redundancy thanks to the addition of a backup system of electrical motors for the docking and sealing mechanism. Improved Micrometeoroid (MMOD) protection with additional panels in the cargo compartment. Luch Russian relay satellites link capabilities enable telemetry and control even when not in direct view of ground radio stations. GNSS autonomous navigation enables real time determination of the status vector and orbital parameters dispensing with the need of ground station orbit determination. Real time relative navigation thanks to direct radio data exchange capabilities with the space station. New digital radio that enables enhanced TV camera view for the docking operations. Unified Command Telemetry System (UCTS) replaces previous Ukrainian Chezara Kvant-V as the Progress spacecraft's on-board radio and antenna/feeder system. Replacement of the Kurs A with Kurs NA digital system.

Launch On 3 February 2021, the State Commission for Testing of the Piloted Space Systems, chaired by Roskosmos head Dmitry Rogozin, approved the latest ISS schedule for 2021 and the first quarter of 2022. A Soyuz-2.1a launched Progress MS-21 to the International Space Station from Baikonur Site 31 on 26 October 2022. Around 2 days after the launch, Progress MS-21 automatically docked with Poisk and continues its mission, supporting Expedition 68 aboard the ISS.

Cargo The MS-21 cargo capacity is 2,520 kg (5,560 lb) as follows:

Dry cargo: 1,357 kg (2,992 lb) Fuel: 702 kg (1,548 lb) Nitrogen: 41 kg (90 lb) Water: 420 kg (930 lb)

Means of attachment of large payloads It delivered SCCS part of MLM Means of Attachment of Large payloads (Sredstva Krepleniya Krupnogabaritnykh Obyektov, SKKO) work platform to ISS. Coupled with LCCS part of this MLM outfitting, delivered to ISS by Progress MS-18, during VKD-55 spacewalk, it was transferred over to Nauka and installed it at the ERA base point facing aft where ERA used to be, when it was launched, where it will be used to mount payloads on the exterior of Nauka module.

Coolant pressure accident On 11 February 2023, the freighter lost coolant pressure days before undocking from ISS, with no impact to the station as cargo had been unloaded and the spacecraft had been loaded with waste to be discarded. This incident was similar to the Soyuz MS-22 coolant loop accident in December 2022. It was undocked on 18 February 2023 as per previous schedule, after which burned in the Earth's atmosphere after deorbit.

See also Uncrewed spaceflights to the International Space Station

References

Illustrations

Worked examples

Example 1 — a first encounter with Progress MS-21

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

In research: Progress MS-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 MS-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 MS-21 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 2022 in Russia, Progress (spacecraft) missions, Spacecraft launched by Soyuz-2 rockets, so understanding it makes those chapters shorter.
In everyday life: Look for Progress MS-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 MS-21 in 20 minutes

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

Frequently asked questions

What is Progress MS-21 in simple terms?

Why does Progress MS-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 MS-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 MS-21.