Luna 16

Key takeaways

Luna 16 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Luna 16 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Luna 16 from memory before moving on to harder problems.

Reference excerpt

Luna 16 was an uncrewed 1970 space mission, part of the Soviet Luna program. It was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth. The 101 grams (3.56 ounces) sample was returned from Mare Fecunditatis. It represented the first successful lunar sample return mission by the Soviet Union and was the third lunar sample return mission overall.

Overview The spacecraft consisted of two attached stages, an ascent stage mounted on top of a descent stage. The descent stage was a cylindrical body with four protruding landing legs, fuel tanks, a landing radar, and a dual descent-engine complex. A main descent engine was used to slow the craft until it reached a cutoff point, which was determined by the on-board computer based on altitude and velocity. After cutoff a bank of lower-thrust jets was used for the final landing. The descent stage also acted as a launch pad for the ascent stage. The ascent stage was a smaller cylinder with a rounded top. It carried a cylindrical hermetically sealed soil-sample container inside a re-entry capsule. The spacecraft descent stage was equipped with a television camera, radiation and temperature monitors, telecommunications equipment, and an extendable arm with a drilling rig for the collection of a lunar soil sample.

Mission summary The Luna 16 automated station was launched toward the Moon from a preliminary Earth orbit and after one mid-course correction on 13 September it entered a circular 111 km with 70° inclination lunar orbit on 17 September 1970. The lunar gravity was studied from this orbit. After two orbital adjustments were performed on 18 and 19 September the perilune was decreased to 15.1 km, as well as the inclination altered in preparation for landing. At perilune at 05:12 UTC on 20 September, the main braking engine was fired, initiating the descent to the lunar surface. Six minutes later, at 05:18 UT, the spacecraft safely soft-landed in its target area at 0°41' south latitude and 56°18' east longitude, in the northeast area of Mare Fecunditatis (Sea of Fertility) approximately 100 kilometers west of Webb crater and 150 km north of Langrenus crater. This was the first landing made in lunar night, as the Sun had set about 60 hours earlier. The main descent engine cut off at an altitude of 20 m, and the landing jets cut off at 2 m height at a velocity less than 2.4 m/s, followed by vertical free fall. The mass of the spacecraft at landing was 1,880 kilograms. Less than an hour after landing, at 06:03 UT, an automatic drill penetrated the lunar surface to collect a soil sample. After drilling for seven minutes, the drill reached a stop at 35 centimeters depth and then withdrew its sample and lifted it in an arc to the top of the spacecraft, depositing the lunar material in a small spherical capsule mounted on the main spacecraft bus. The column of regolith in the drill tube was then transferred to the soil sample container. After 26 hours and 25 minutes on the lunar surface, at 07:43 UT on 21 September, the spacecraft's upper stage lifted off from the Moon. The lower stage of Luna 16 remained on the lunar surface and continued transmission of lunar temperature and radiation data. Three days later, on 24 September, after a direct ascent traverse with no mid-course corrections, the capsule, with its 101 grams of lunar soil, reentered Earth's atmosphere at a velocity of 11 kilometers per second. The capsule parachuted down 80 kilometers southeast of the town of Jezkazgan in Kazakhstan at 05:25 UT on 24 September 1970. Analysis of the dark basalt material indicated a close resemblance to soil recovered by the American Apollo 12 mission. According to the Bochum Observatory in Germany, strong and good-quality television pictures were returned by the spacecraft. Luna 16 was a landmark success for the Soviets in their deep-space exploration program; the mission accomplished the first fully automatic recovery of soil samples from the surface of an extraterrestrial body. On 10 June 1971, the Soviet Academy of Sciences exchanged Luna 16 samples with NASA in Moscow, receiving samples from Apollo 11 and Apollo 12. A 0.4825 g sample of material from a depth of 27 cm was sent to Britain.

Legacy

Three tiny samples (0.2 grams) of the Luna 16 soil were sold at Sotheby's auction for $442,500 in 1993. The samples were resold by Sotheby's for US$855,000 on 29 November 2018. A series of 10-kopeck stamps was issued in 1970 to commemorate the flight of Luna 16 lunar probe and depicted the main stages of the programme: soft landing on Moon, launch of the lunar soil sample return capsule, and parachute assisted landing back on Earth.

Replicas of Luna 16 are on display at the Memorial Museum of Cosmonautics and Tsiolkovsky State Museum of the History of Cosmonautics.

Illustrations

Worked examples

Example 1 — a first encounter with Luna 16

Start with the simplest possible case. Write down what Luna 16 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 Luna 16 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 Luna 16 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 Luna 16

In research: Luna 16 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 Luna 16 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: Luna 16 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1970 in the Soviet Union, 1970 on the Moon, Luna programme, so understanding it makes those chapters shorter.
In everyday life: Look for Luna 16 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.

How to study Luna 16 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Luna 16 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 Luna 16 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Luna 16 in simple terms?

Luna 16 was an uncrewed 1970 space mission, part of the Soviet Luna program. It was the first robotic probe to land on the Moon and return a sample of lunar soil to Earth.

Why does Luna 16 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 Luna 16?

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 Luna 16.