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Sputnik Declassified

Viewing Ideas

Before Watching

  1. Have students create a time line. To help students understand the historical context in which Sputnik was launched, have them make a time line that includes political events on the top of the time line and space exploration events on the bottom part of the time line. Have each group summarize on a 5 x 8-inch file card what the event was and why it was important. Produce a time line (a string 7 meters long) that starts at 1900 and ends at 1970. Have student groups attach their cards at the appropriate place on the time line and have each read their card descriptions to the class.

    Socio-Political Events

    Space Exploration Events

    • World War I (1914–1918)

    • World War II (1939–1945)

    • Cold War (1940s–1990s)

    • U.S. detonates first atomic bomb in New Mexico (1945)

    • First Soviet atomic bomb detonated (1949)

    • First hydrogen device tested (1951)

    • International Council of Scientific Unions calls for artificial satellites to be launched in International Geophysical Year (1957–58)

    • Orville and Wilbur Wright make first power-driven flight (1903)

    • Robert Goddard creates the first working liquid-fuel rocket (1926)

    • First ballistic missile, V-2, launched (1942)

    • Chuck Yeager breaks the sound barrier in the Bell XS-1 (1947)

    • X-15 becomes first winged aircraft to attain velocities of Mach 4, 5, and 6 (circa 1957)

    • WAC Corporal rocket becomes first U.S. missile to penetrate outer space (1949)

    • X1A achieves record altitude of 90,440 feet (1954)

    • Sputnik 1 launches (1957)

    • Explorer 1 launches (1958)

  2. Create a scale drawing of Earth's atmosphere. Sputnik 1 was the first of many satellites launched into orbit around Earth. Ask students how many artificial satellites are orbiting Earth now? (Scientists estimate that there are more than 3,000 working satellites, and at least 6,000 non-working [space junk] satellites.) Show an image of Earth's atmosphere taken from space and point out how thin Earth's atmosphere is compared to the diameter of the planet (see Links and Books for a link to a photo). To launch a satellite successfully, a rocket needs to lift the weight of the satellite above as much of the atmosphere as possible so that air friction will not slow the satellite appreciably and bring it crashing back to Earth. On a piece of plain white paper, have students plot the layers of the atmosphere to scale and show the average orbital distance of the Space Shuttle and Sputnik. Use a scale of 1 millimeter = 3 kilometers. Have students draw a line about 2 centimeters from the bottom of the paper to represent the surface of Earth. Here are some average data points to plot:

    • Troposphere: 0 to 9 kilometers

    • Stratosphere: 9 to 50 kilometers

    • Mesosphere: 50 to 85 kilometers

    • Thermosphere: 85 kilometers to 640 kilometers

    • Exosphere: 640 kilometers to 9,000 kilometers (Students won't be able to plot the entire extent of this on an 8.5- x 11-inch piece of paper. Tell them they can just draw an arrow pointing up.)

    After the layers are plotted, have students place the following on the diagram.

    • At 16 kilometers, place "90 percent of atmosphere by mass is below this altitude"

    • At 100 kilometers, place "99.99997 percent of atmosphere by mass is below this altitude"

    • At 250 kilometers, place "Sputnik 1"

    • At 330 kilometers, place "International Space Station"

    After their scale drawings are completed, ask students what the technical difficulties may be of launching a rocket and satellite to place it in orbit around Earth? (Students may list variables like weight of the payload [satellite], overcoming Earth's gravitational force, using enough fuel to get the satellite into orbit, and air friction.) If they do not mention it, tell students that Earth's rotation must also be taken into account. Since Earth rotates at a rate of 1,000 miles per hour near the equator, U.S. launching sites like the Kennedy Space Center launch rockets with their satellites in an easterly direction to take advantage of rotational speed instead of going against it. Many satellites are launched in polar orbits (south to north) so they can essentially see the entire Earth in a prescribed number of orbits.

  3. Discuss the implications of Sputnik's launching. Sputnik, the world's first artificial satellite, was launched October 4, 1957. About the size of a beach ball, the satellite weighed 184 pounds and orbited Earth every 96 minutes. It is impossible to comprehend the furor that the launching caused in the United States without understanding the state of extreme tension caused by the Cold War.

    • Ask students what they think is meant by the term Cold War. (The term Cold War, as it refers to the tensions of the Soviet Union and its neighbors, was coined by author George Orwell. In an essay that was published October 19, 1945, in the London Tribune, Orwell wrote of the Soviet Union as "a state which a permanent state of ‘cold war' with its neighbors.")

    • Sputnik broadcast a signal to Earth from its radio beacon when it was in orbit (you can play the signal at

    Why was this signal so amazing but at the same time such a threat to American society? (The broadcast of a signal from outer space was a tremendous achievement, but for many people in the government, it conjured up a spy-plane-from-space scenario. Sputnik demonstrated that the Soviet Union (USSR) was ahead of the United States in space flight, and signaled the potential for the USSR to launch nuclear weapons from Europe. The launch led to the creation of the National Aeronautics and Space Administration, heralding a new era of U.S. space research.)

  4. Use Google Earth to simulate what satellites "see" from different distances from Earth. Arguably one of the primary reasons for developing satellites in the first place by the military-industrial complex was to spy on each other. Prior to launching "spy" satellites, the United States and the Soviet Union used high altitude spy planes (such as the U-2 spy plane) and developed camera and telescope imaging technology to take images of ground facilities. This technology first came to the public's attention during the Cuban missile crisis in 1961. Download pictures of the Cuban missiles or missile bases (see Links and Books for a link to a photo) and show one to students. Have students duplicate this feat by using Google Earth to inspect one of the following places:

    • a local airport

    • a large U.S. airport such as Logan in Boston, JFK in New York, or Dallas-Fort Worth

    • a naval yard or ship-building facility

    Have students take a screen shot and file an intelligence report about the site. How many planes can they spot? What else can they see? Can they see other vehicles, fuel supplies, and hangars where weapons or planes could be stored?

After Watching

  1. Research satellite development. Sputnik was the first of hundreds, and now thousands, of satellites placed into orbit by the USSR, United States, and many other countries. Organize your class into groups and assign each group one of the satellite types listed below. Each group should make a poster that describes:

    • general size, weight, structure, what instruments it uses

    • primary user (science, military, industry) and specific tasks

    • type of orbit and typical orbital path and height (see Links and Books for information on types of orbits)

    After students have finished their posters, have a poster viewing session so students can compare the different types of satellites.

    • Astronomical satellites
      satellites used for observation of distant planets, galaxies, and other outer space objects

    • Biosatellites
      satellites designed to carry living organisms, generally for scientific experimentation

    • Communications satellites
      satellites stationed in space for the purpose of telecommunications

    • Navigational satellites
      satellites that use radio time signals transmitted to enable mobile receivers on the ground to determine their exact location

    • Reconnaissance satellites
      Earth observation satellite or communications satellite deployed for military or intelligence applications

    • Earth observation satellites
      satellites intended for non-military uses such as environmental monitoring, meteorology, map making etc.

    • Space stations
      man-made structures that are designed for human beings to live on in outer space

    • Weather satellites
      satellites that primarily are used to monitor Earth's weather and climate

  2. Research the history of the getting to the moon. The launching of Sputnik 1 and the subsequent launch of Explorer 1 led directly to an even greater goal: landing a manned spacecraft on the moon. After the launch of Explorer in 1958, the race to the moon was on. Assign a milestone to each student or groups of students. Direct each group to synopsize on a 5 x 8-inch file card what the achievement was and why it was important in the quest to land on the moon. Have students either extend the previous time line they did to 1970 and attach their cards, or construct a similar new time line.





    First artificial satellite in Earth orbit


    Sputnik 1


    First animals sent to and returned from orbit alive


    Sputnik 5


    First probe to go near the Moon


    Luna 1


    First probe to impact the Moon


    Luna 2


    First controlled, unoccupied landing on the Moon; first to transmit from the Moon's surface


    Luna 9


    First probe to orbit the Moon


    Luna 10


    First man in space, first man to orbit the Earth


    Vostok 1


    First one-day flight


    Vostok 2


    First flight over three days long


    Vostok 3


    First woman in space


    Vostok 6


    First spacewalk (EVA)


    Voskhod 2


    The first rendezvous in space


    Gemini 6A


    First docking with another spacecraft


    Gemini 8


    First manned mission to leave Earth orbit, first to orbit the Moon


    Apollo 8


    First successful manned flight of a spacecraft capable of landing on the Moon (Apollo Lunar Module)


    Apollo 9


    First manned landing on the Moon


    Apollo 11


  3. Model satellite orbits on paper. Satellites like Sputnik were launched with orbits relatively close to Earth in terms of average altitude above Earth's surface. This was a practical matter since the greater the distance above Earth, the greater the energy required to deliver the satellite to that height. All orbits of satellites, moons, and planets are elliptical in shape. Each Earth satellite has an elliptical orbit with a point of closest approach (perigee), and a point that is farthest away (apogee).

    Have students construct a two-dimensional model of the orbits listed below. Have them draw a circle 60 millimeters in diameter on a piece of paper. Ask students to predict what the orbit of Sputnik would look like if Earth were scaled down to the size of a tennis ball (about 60 millimeters in diameter). Have them draw the orbit with pencil on their sheet of paper.

    Give students the average diameter of Earth (12,600 kilometers) and use the formula below to help them set up the first ratio and proportion to find the average orbital distance from Earth for each type of satellite.


    height of satellite above Earth in km
    actual diameter of Earth in km




    (unknown height of satellite in mm)
    diameter of model Earth in mm

    For Sputnik:


    215 km
    12,600 km




    60 mm


    x =


    215 km X 60 mm
    12,600 km


    = 1.02 mm

    Thus, the orbit would need to be roughly a circle only a single millimeter above the surface of Earth!

    Sputnik 1: perigee = 215 kilometers, apogee = 939 km; average 250 kilometers

    Explorer 1: perigee = 360 kilometers, apogee = 2500 kilometers: average 575 kilometers

    International Space Station: perigee = 320 kilometers, apogee = 347 km, average = 334 kilometers

    Weather satellites in polar orbits (south to north): average = 860 kilometers

    Communication/TV satellites in geosynchronous orbit (24 hours): = 36,000 kilometers

Links and Books


NOVA—Sputnik Declassified
Features an excerpt from a book about V-2 rocket pioneer Wernher von Braun, details how satellites are used to survey Earth, includes a time line of the space race, and features a way to assemble a V-2 rocket online.

Cold War
Features a synopsis and history of the Cold War.

The Cuban Missile Crisis
Provides details of the kind of evidence that precipitated the Cuban missile crisis and an aerial photo of missiles in Cuba.

Earth's Atmosphere
Provides details and diagrams of Earth's atmosphere and layers.

How Satellites Work
Explains how satellites work and how they are launched, and describes different types of satellite orbits and typical altitudes.

Shuttle Mission Imagery
Features a photo with an oblique view of Earth's horizon and atmosphere.


The Cold War: A New History
by John Lewis Gaddis. New York: Penguin Press, 2005.
Provides a comprehensive look at the Cold War.

Sputnik: Shock of the Century
by Paul Dickson. New York: Walker & Company, 2001.
Chronicles in detail the complex series of events that led up to the launch of Sputnik.

Viewing Ideas Author

Jeff Lockwood taught high school astronomy, physics, and Earth science for 28 years. He has authored numerous curriculum projects and has provided instruction on curriculum development and science teaching methods for more than a decade.

Teacher's Guide
Sputnik Declassified
Koch Foundation

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