Why NASA Wants an Equatorial Launch Site – Part I
By Gary Deel, Ph.D., JD
Faculty Director, School of Business, American Military University
and Ernest Rahn, Ph.D.
Adjunct Professor of Space Studies, School of STEM, American Military University
This is the first of two articles on how NASA could economically launch more rockets and satellites into space.
NASA is by far the most well-funded, well-developed space agency on the planet. Even as its budget — relative to total U.S. tax income — has continually been reduced over the decades since the Apollo era, NASA still receives several times the funding of its largest international competitors. As a result, NASA enjoys greater staffing, better facilities and an overall larger presence on the world stage of space exploration.
Get started on your Space Studies Degree at American Military University.
However, no matter how much funding and support NASA receives, it has always lacked one critical element of significant importance to space launch activity: an equatorial launch site.
Launch site location is important for space agencies and space launch providers. A launch site determines the types of orbits around the Earth that a spacecraft can enter and how much fuel (i.e. money) it will take to achieve such orbits.
Objects in Orbit around Earth Are Not Simply Floating in Space
To comprehend why an equatorial launch site is so important, you must understand a few key concepts of orbital mechanics. First, an object in orbit around the Earth is not simply floating in space around us. Instead, it is actually in a state of constant freefall toward the Earth.
However, an orbiting object never actually hits the Earth because it moves sideways at such a speed that its horizontal movement offsets its freefall in the precise amount to account for the curvature of the Earth. So it continues to fall around the Earth, but never actually collides with us.
This concept was first discovered and simplified in a thought experiment by Sir Isaac Newton. This 18th-century British mathematician suggested imagining firing a cannonball horizontally in any direction. Assuming there is no air resistance and no trees, mountains, or buildings to obstruct the cannonball’s trajectory, it will travel a short distance and then fall to the ground.
Now imagine we collect the cannonball and fire it again, but this time with a little more force. The cannonball travels a little further before hitting the ground.
Suppose we keep doing this, increasing the force each time we fire the cannonball. If we continue, we will eventually reach a point (i.e. a projectile speed) when the cannonball is traveling so fast that its rate of descent is equal to the rate at which the surface of the Earth curves away from it. The cannonball would eventually travel all the way around the other side of the Earth and hit us in the back of the head.
Assuming we move out of the way, at such a speed the cannonball would simply continue to make endless circles around the Earth without ever hitting the ground. And that is all an orbit is.
The Surface of the Earth Actually Rotates at Different Speeds Depending on Latitude
Now that we understand orbits, we must also remember that the Earth is spinning. We know this intuitively; it’s what creates our day-night cycles. However, we tend to take for granted how fast the Earth is spinning because we don’t “feel” any motion.
The surface of the Earth actually rotates at different speeds depending on latitude. This is because different latitudes are at different distances from the axis of rotation. That is the imaginary line through the center of the Earth that runs from the North Pole to the South Pole, on which the Earth rotates like a spinning top.
This is easy to understand with a simple illustration. Consider that at the equator the circumference of the Earth is roughly 40,000 km (24,855 miles). However, at 45 degrees North latitude, the circumference is only about 28,000 km (17,398 miles).
This is because the Earth is “fatter” in the middle and “thinner” closer to the poles, as all spheres are. But we know that at any given longitude, the Earth makes one full rotation every 24 hours.
For example, Toronto, Buffalo, Pittsburgh, Charleston and Miami are all within roughly one to two degrees longitude of each other. But because these cities are at different latitudes, they are at different distances from Earth’s axis of rotation. However, they all make complete rotations once every 24 hours because they move at different speeds.
Locations further from the axis of rotation (i.e. nearer to the equator) move faster, while those closer and nearer to the poles move more slowly. (Think of ice skaters forming the spokes of a spinning and expanding wheel around one skater barely moving in the center. As new skaters join the line they must skate faster than the ones already there. The last skater to join the wheel must skate exceedingly fast to link up.)
Why does all this matter? The answer brings us to the point of this article. Generally, spaceship launches travel east to take advantage of the “free” speed afforded by Earth’s rotation in this eastward direction.
This movement can make a big difference because the speed needed for a stable orbit varies with altitude.
As an example, the International Space Station (ISS) orbits about 250 miles above the Earth. To maintain that stable orbit, the ISS moves along at more than 17,000 mph. Given that fuel for space launches can be very expensive, space agencies are happy to take advantage of the free “push” from the Earth’s rotation (think of a slingshot) whenever and wherever they can.
And this is the crux of the issue. NASA would stand to save a considerable amount of money on launches if it could do so from a location as near as possible to the equator.
Unfortunately, the United States has no territorial possessions near or on the equator. Still, our nation has allies around the world and significant political and economic leverage. The U.S. should seek out an opportunity to partner with an equatorial nation — such as those in South America — for its launches, if such an agreement could be negotiated. Fortunately, we took a major step in this direction earlier this year by signing a technology safeguards agreement with Brazil that might present a huge opportunity for NASA.
In Part II, we will discuss the details of this opportunity and what it might actually mean for the U.S. space agency.
About the Authors
Dr. Gary Deel is a Faculty Director with the School of Business at American Military University. He holds a JD in Law and a Ph.D. in Hospitality/Business Management. He teaches human resources and employment law classes for American Military University, the University of Central Florida, Colorado State University and others.
Dr. Ernest Rahn is a faculty member in the School of Science, Technology, Engineering and Math at American Military University. His academic credentials include a B.S. in Professional Aeronautics and an M.S. in Aeronautical Science – Aerospace Safety Systems and Aerospace Management from Embry-Riddle Aeronautical University; an M.S. in Adult Education from Troy University; and a Ph.D. in Business Administration – Aeronautical Science Management from Northcentral University.