Sunday December 7 I’ll be flying on the Zero-G Corporation’s “G-Force-1″ airplane (a modified Boeing 727) out of the Space Coast Regional Airport. The pilots of G-Force-1 fly the plane as close as possible to a perfect parabola at a constant horizontal speed and a constant negative acceleration of 9.8 meters per second squared. That is, they make the plane follow the path of a freely falling object. Because all objects, regardless of mass, fall at the same rate (remember Galileo and that famous leaning tower), I and everyone else inside the plane will be in a state of freefall for about 25 seconds per parabola. During that time we will experience the same sensation as astronauts orbiting the Earth.

At the end of each parabola, the plane must accelerate upward giving us a weight of about 1.8 times normal (or 1.8 g’s). During one parabola I’ll be testing a modified experiment on the formation of planets. In particular, I’ll be studying the effects of low-speed collisions between a large object and a collection of small particles to see how well things stick together or blow apart when gravity isn’t present to hold them together. I have done similar experiments on NASA’s version of G-Force-1 before (affectionately known as the “vomit comet”). NASA’s plane typically does 45 parabolas per flight, while Zero-G is kinder to its passengers and limits the parabolas to one simulating martian gravity, two simulating lunar gravity, and 12 zero-g parabolas. With that profile, I am confident I will avoid the upset stomach that plagued me on flights on NASA’s plane.