physics

Kosmos 1402

Kosmos 1402 is a physics 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 Kosmos 1402 rather than just read about it. In short: Kosmos 1402 (Russian: Космос 1402) was a Soviet spy satellite that malfunctioned, resulting in the uncontrolled re-entry of its nuclear reactor and its radioactive uranium fuel. Kosmos 1402 was launched on August 30, 1982, and re-entered the atmosphere on 23 January 1983.

Key takeaways

Kosmos 1402 belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kosmos 1402 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kosmos 1402 from memory before moving on to harder problems.

Reference excerpt

Kosmos 1402 (Russian: Космос 1402) was a Soviet spy satellite that malfunctioned, resulting in the uncontrolled re-entry of its nuclear reactor and its radioactive uranium fuel. Kosmos 1402 was launched on August 30, 1982, and re-entered the atmosphere on 23 January 1983. The fission reactor entered a few days later; on 7 February 1983. Kosmos 1402 was a RORSAT surveillance satellite that used radar for monitoring NATO vessels. The power source for the satellite was a BES-5 nuclear fission reactor, which used about 50 kilograms (110 lb) of enriched uranium as a fuel source. The satellite operated in low Earth orbit, and the reactor was designed to eject to a higher parking orbit at the end of the satellite's mission, or in the event of a mishap. This ejection mechanism was implemented in the RORSAT satellites after a nuclear accident caused by a previous malfunction of Kosmos 954, five years earlier over Canada's Northwest Territories. In response to the Kosmos 954 mishap, RORSAT satellites were modified with an ejection system for their nuclear reactors. This ejection system would allow the reactor section to be ejected in the event of a malfunction, or at the end of the satellite's service life, so the radioactive core could be placed in a disposal orbit (about 1000 km), where the fuel would remain for 500 years.

Accident On 28 December 1982, the ejection system in Kosmos 1402 failed to adequately jettison the reactor to a higher orbit, and the satellite split into three parts and began to tumble out of control. The three main sub-components were the reactor with its booster engine, the instrument section of the satellite with the expended second stage of the launch vehicle, and the radar antenna. If the uranium core were to explode or shatter in the atmosphere, and radioactive fragments fell near a populated area, the resulting nuclear contamination could have caused a significant and widespread hazard. Because of this concern, the Soviet engineers had re-designed the reactor to completely burn up in the atmosphere, so that nothing would reach the ground. But this information was not verified by other countries at the time. The uncertainty of the reentry location and time, coupled with concerns of radioactive contamination, triggered many countries to place emergency response teams on high alert. Military aircraft, ships, and personnel were mobilized in anticipation. Countries with response plans included United States, Canada, Belgium, Australia, Oman, UAE, West Germany, France and Sweden. The antenna section was the first part of the satellite to re-enter. It burned up in the atmosphere on December 30, 1982. The main satellite bus of Kosmos 1402 reentered the Earth's atmosphere on January 23, 1983, south of Diego Garcia in the Indian Ocean (25°S 84°E). No debris was recovered, but it is believed that the satellite disintegrated then crashed into the sea. The satellite was visible over the United Kingdom, for about a minute, on the night before impact. The reactor section and core continued to orbit for another two weeks. It re-entered on February 7, 1983, over the South Atlantic Ocean, near Ascension Island (19°S 22°W). The reactor is believed to have completely burned up into particles and dispersed to safe levels of atmospheric radioactivity.

Aftermath Subsequent RORSATs were equipped with a backup (secondary) core ejection mechanism – when the primary ejection mechanism failed on Kosmos 1900 in 1988 this system succeeded in raising the core to a safe disposal orbit. After this accident, launches of new US-A series satellites were stopped for a year and a half. Radioactive strontium was detected in rain samples from Fayetteville, Arkansas in the months following the incident. The radioactive material originated in the Kosmos 1402 core. Another investigation determined that 44 kg of uranium had been dispersed into the stratosphere after the incident. The incident triggered widespread discussion about nuclear technology in space, including topics related to space law, insurance and liability, militarization, nuclear safety and security.

Worked examples

Example 1 — a first encounter with Kosmos 1402

Start with the simplest possible case. Write down what Kosmos 1402 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 Kosmos 1402 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 Kosmos 1402 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 Kosmos 1402

In research: Kosmos 1402 appears in physics 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 Kosmos 1402 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: Kosmos 1402 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1982 in the Soviet Union, 1983 in the Soviet Union, Kosmos satellites, so understanding it makes those chapters shorter.
In everyday life: Look for Kosmos 1402 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 “Kosmos 1402” →

Affiliate

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

How to study Kosmos 1402 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kosmos 1402 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 Kosmos 1402 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kosmos 1402 in simple terms?

Why does Kosmos 1402 matter?

Because it connects several physics 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 Kosmos 1402?

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 Kosmos 1402.