science

Surveyor 2

Surveyor 2 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 Surveyor 2 rather than just read about it. In short: Surveyor 2 was to be the second lunar lander in the uncrewed American Surveyor program to explore the Moon. After launch on September 20, 1966, a mid-course correction failure resulted in the spacecraft losing control.

Key takeaways

Surveyor 2 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Surveyor 2 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Surveyor 2 from memory before moving on to harder problems.

Reference excerpt

Surveyor 2 was to be the second lunar lander in the uncrewed American Surveyor program to explore the Moon. After launch on September 20, 1966, a mid-course correction failure resulted in the spacecraft losing control. Contact was lost with the spacecraft at 9:35 UTC, September 22.

Background

On February 3, 1966, the Luna 9 spacecraft was the first spacecraft to achieve a lunar soft landing and to transmit photographic data to Earth. On May 30, Surveyor 1 launched, landing on Oceanus Procellarum on June 2. This craft also transmitted photographic data back to Earth. This spacecraft was the second of a series designed to achieve a soft landing on the Moon and to return lunar surface photography for determining characteristics of the lunar terrain for Apollo program lunar landing missions. Besides transmitting photos, Surveyor 2 was planned to perform a 'bounce', to photograph underneath its own landing site. It was also equipped to return data on radar reflectivity of the lunar surface, bearing strength of the lunar surface, and spacecraft temperatures for use in the analysis of lunar surface temperatures.

Launch

The launch took place from Space Launch Complex 36A at Cape Kennedy, Florida aboard an Atlas-Centaur rocket. Liftoff was at 12:32 UTC on 20 September 1966.

Failure The target area proposed was within Sinus Medii. The Atlas-Centaur had placed Surveyor 2 on a path to the Moon that was only 130 km from its aim point. During the midcourse correction maneuver one vernier thruster failed to ignite, resulting in unbalanced thrust that caused the spacecraft to tumble for its remaining 54 hours. Attempts to salvage the mission failed. Contact was lost with the spacecraft at 9:35 UTC, September 22. The spacecraft was targeted at Sinus Medii, but crashed near Copernicus crater. The spacecraft was calculated to have impacted the lunar surface at 03:18 UTC, September 23, 1966. Its weight on impact was 644 lb (292 kg), and speed was about 6000 miles an hour (2.6 km/s = 5840 mph), slightly over lunar escape velocity (2.4 km/s) and similar to the impact velocities of the Ranger program spacecraft.

Aftermath Lunar exploration continued to be challenging. The next Soviet mission, Cosmos 111, was launched on March 1, 1966, but failed to reach a proper lunar trajectory, re-entering Earth's atmosphere two days later. Surveyor 3 soft-landed on April 20, 1967, at the Mare Cognitum portion of the Oceanus Procellarum. It transmitted a total of 6,315 television images to the Earth. There were seven Surveyor missions; five were successful. Surveyors 2 and 4 failed. Each consisted of a single uncrewed spacecraft designed and built by Hughes Aircraft Company. The precise location of the Surveyor 2 crash site is unknown.

Centaur upper stage

The Centaur upper stage of the rocket used to launch Surveyor continued on its original trajectory past the Moon, placing it into a solar orbit similar to that of the Earth. The Centaur was untracked from that point forward. In August 2020, NASA announced the sighting of an object in a solar orbit which could shortly make a close pass with the Earth. On September 23, 2020, NASA announced that this was likely the lost Centaur booster, and likely to be re-captured into Earth orbit. This would be the second time that a rocket upper stage has done so, after the upper stage of a Saturn V rocket from the Apollo 12 launch re-entered Earth orbit in 2002. In December 2020, NASA confirmed that it was the lost Centaur stage.

Illustrations

Worked examples

Example 1 — a first encounter with Surveyor 2

Start with the simplest possible case. Write down what Surveyor 2 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 Surveyor 2 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 Surveyor 2 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 Surveyor 2

In research: Surveyor 2 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 Surveyor 2 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: Surveyor 2 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1966 on the Moon, LQ19 quadrangle, Missions to the Moon, so understanding it makes those chapters shorter.
In everyday life: Look for Surveyor 2 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 “Surveyor 2” →

Affiliate

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

How to study Surveyor 2 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Surveyor 2 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 Surveyor 2 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Surveyor 2 in simple terms?

Why does Surveyor 2 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 Surveyor 2?

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 Surveyor 2.