A Physical Well, or a Well of Physics

To an astrophysicist, the Gravity Well is a physical force, a field of attraction between two bodies in space, diminishing with distance. For engineers, the Gravity Well is the great physical challenge of overcoming that force. A vehicle must carry its weight—along with the weight of its fuel—and achieve sufficient velocity to overcome the force of gravity. That means pushing the vehicle to a speed of at least 25,000 miles an hour to escape Earth’s gravity.

If that vehicle travels to another body in space, such as Mars, then that body’s own gravity well presents another challenge. The vehicle must generate enough force to reduce its speed to zero. Then, if a return trip is planned, the vehicle must burst out of that gravity well and, as it approaches Earth, decelerate.

All of these feats deal with a single physical challenge: to overcome the forces of gravity. Einstein described the force of gravity as a curvature of space; in other words, a well shape, with Earth at the bottom. Much of the efforts of commercial space companies deal with the problem of overcoming gravity enough to get satellites and vehicle into Earth orbit, and slowing down reusable rockets so that they return intact to the surface. To the scientists and engineers involved in these efforts, the Gravity Well is about gravity: a powerful force on all objects.

The Well is about gravity. But it’s something else as well. We’ll get into that in the next post.