Sofya Fadeeva (University of Chicago Intern) Stevan Akerley (NSS Space Ambassadors Lead) Paul Phister (NSS Space Ambassador) Frances Dellutri (NSS Director of Education)
Lesson Summary:
How does a rocket guide itself? This was a question for Robert Goddard who launched the first liquid-fuel rocket and put rocketry where it is today! What is the device that helps determine whether an aircraft maintains the right trajectory, and what physics principles/laws stand behind this device? In this lesson, students will learn about gyroscopes – what they are and how they work, how they were developed and implemented in spaceflight, and how they’re being used today.
Goals:
Understand what a gyroscope is and how/why it works
Learn how gyroscopes are used in rocket navigation, beginning with Robert H. Goddard and their evolution.
Become familiar with uses of gyroscopes today
Age level: Grades 6-8
US Next Generation Science Standards (NGSS) (www.nextgenscience.org):
1. Asking questions (for science) and defining problems (for engineering) 2. Developing and using models 3. Planning and carrying out investigations 6. Constructing explanations (for science) and designing solutions (for engineering) 8. Obtaining, evaluating, and communicating information
How is a rocket’s path controlled after launch? How does it stay on course once it’s in space?
Rockets and spacecraft use something called gyroscopes to help stay balanced and on course. Gyroscopes are essential for spaceflight: without such tools, rockets would be unable to stay on track, and crashes would be inevitable. Let's learn what gyroscopes are and how they manage to guide rockets!
Rockets were a part of warfare and entertainment for almost a thousand years. The gyroscope was an important addition to the first liquid-fuel rockets, launched by Robert H. Goddard.
See this 2-minute video to get an idea of Goddard’s role in the development of modern rocketry:
Dr. Robert H. Goddard (1882–1945), born in Worcester, Massachusetts, is considered the “father of modern rocketry.” In 1907, while a student at Worcester Polytechnic Institute, he fired a rocket engine in the basement of the physics building, getting the attention of school officials. Seven years later, he patented his rocket inventions. In 1920, he published “A Method of Reaching Extreme Altitudes,” in which he suggested using rockets to carry weather instruments aloft. Dr. Goddard developed and a successfully launched the first liquid-fueled rocket in 1926. He continued to develop his rockets and was able to produce one that went close to or faster than the speed of sound (1935). He developed the first practical automatic steering device for rockets. (From Scouting America. Merit Badge Series: Space Exploration.)
NSS Space Ambassador Loretta Hall has contributed this piece to the Gyroscope in Space Lesson:
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As Dr. Goddard’s rockets became more powerful, he faced a serious problem: how to make them go where he wanted them to go. Rather than flying upward to new heights, his rockets sometimes turned and flew horizontally. He couldn’t control what they might hit.
But he figured out a way to keep them flying upward. He used a device called a gyroscope. In the middle of a gyroscope, a disk is attached to a long axle. The ends of the axle are attached to a ring that can spin around the disk without touching it. That ring is nested inside two other free-spinning rings so that all three are perpendicular to each other. When the inner disk is made to spin fast, its axis will keep pointing in the same direction no matter how the three rings rotate around it.
Goddard mounted a gyroscope in his rocket so its axis lined up with the rocket’s nose and base. If the rocket tried to move away from a vertical direction, the gyroscope would sense a force trying to pull it away from where it was pointing. Goddard used that force to move vanes in the rocket’s exhaust stream. The vanes would move so that the exhaust gas pushing against them would move the rocket back to the direction the gyroscope was pointing. The rocket would fly upward, not sideways.
What is a gyroscope?
In simple terms, gyroscope—a
spinning disc mounted in gimbals that could maintain orientation regardless of
external motion. The gimbals are a device that keeps an instrument like a compass or a gyroscope in a horizontal position in a vessel or aircraft. Typically, they consist of rings that pivot at right angles.
A gyroscope's frames can rotate separately, which is allowed by gimballing. Take a look at this demo that shows the different relative positions of a gyro's gimbal frames: https://demonstrations.wolfram.com/Gyroscope/
The physics of gyroscopes
In this 5-minute video "Gyroscopes" from Science Online, angular momentum is addressed. Angular momentum is the circular or rotational movement of object such as a planet orbiting its star, our moon orbiting earth, or a spinning gyroscope. The spinning or rotational movement causes a force that keeps the object moving in its circular path or rotating around another object.
Take a look at this simulation that shows how angular velocity, the position of the disk, the tilt of the axis, and the intensity of friction affect a gyroscope's motion:
Here's a 30-second video short (How do gyroscope really work? from Crunch Labs) that shows how a gyroscope works on Earth and in Space. When the rotor is not spinning, the gyroscope tumbles head-over-heels. Watch for the orientation of the gyroscope's outside posts in the images below.
In this first image, the astronaut is flipping a gyroscope without the rotor spinning.
Notice the posts of the gyroscope as it responds to Astronaut Peake and tumbles in space.
When the rotor is spinning, the gyroscope does not respond to the astronaut's 'jabs' to disturb its stability.
British astronaut
in this 30 second video.
Here is a 4 min video showing how gyroscopes in airplanes indicate altitude and turning. Gyroscope basics.
Using a simple top to explain gyroscopes
Toy Top: Simple Gyroscope
The simplest example of a gyroscope is a child’s toy top. They come in many variations from the simple to the elaborate. But they use the same angular momentum that gyroscopes use.
The angular momentum principle catches the amazed attention of children, starting the STEM learning process, via curiosity and amazement – How can that work….?
The top consists of a balanced mass (bottle cap and cardboard disc in the activity above) rotating on a spin axis (skewer). At an RPM (rotations per minute) adequate to create a stable spin axis, vertical to a level surface (table top or floor). The friction on the spinning axis slows the spin rate down to a point where it becomes unstable. The result is a precession, or wobble, of the spin axis, until the top falls over due to gravity exceeding the force of angular momentum. placeholder sentence here
This activity shows how to build a simple spinning toy top using household items.
How a gyroscope guides a rocket
This 15-minute video shows the surprising behavior of a simple gyroscope and goes on to show how it became a crucial tool in aerial navigation, delving into some details of gyroscopic navigation in rockets:
In 1744, the British warship HMS Victory sank during
a storm in the English Channel, taking with it more than 1,100 men, rumored
treasure, and something of even greater historical importance: John Serson’s
“whirling speculum.” Inspired by a child’s spinning top, this early forerunner
of the gyroscope was designed as an artificial horizon to help sailors navigate
when the real horizon was obscured by mist or haze. Although Serson perished
with his invention, his idea planted the seed for a technology that would, over
centuries, revolutionize navigation on land, sea, air, and eventually space.
A century later, French physicist Léon Foucault perfected
the concept with the gyroscope—a spinning disc mounted in gimbals that could
maintain orientation regardless of external motion. With the advent of electric
motors, gyroscopes became indispensable in ships and airplanes, eventually
leading to the invention of the gyrocompass in the early 1900s. Combined with
other instruments such as accelerometers and magnetometers, gyroscopes provided
stable, reliable navigation data. These breakthroughs formed the backbone of
autopilot systems, missile guidance, and even spacecraft navigation.
As gyroscopes became smaller and more advanced, including
micro-electro-mechanical and laser-based designs, they spread into consumer
technology. Together with GPS, these sensors enabled smartphones, gaming
systems, and virtual reality devices to understand their position and
orientation. This miniaturization also fueled the rise of drones. What began as
clumsy military experiments with bomb-carrying balloons in the 19th century
evolved into today’s nimble pilotless aircraft capable of filming movies, conducting
surveys, delivering medical supplies, and—potentially—revolutionizing retail by
carrying groceries or even passengers.
The path from Serson’s lost “whirling speculum” to modern
drones and GPS underscores how innovation often emerges from centuries of
incremental progress. Drones already play vital roles in remote regions, such
as rural China, where they deliver goods to villages lacking road
infrastructure. Yet challenges remain, from weather resilience to solving the
“last mile” delivery problem in urban areas. If drones can eventually navigate
storms as reliably as ships with gyrocompasses once did, then the long-ago vision
of John Serson—creating a stable horizon in any conditions—will have reached
its fullest expression in the technologies that shape our modern economy.
Postcards to Space!
Send a Postcard to Space through NSS Supported Blue Origin Club For The Future initiative!
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