Sunday, September 29, 2013

What is Microgravity?

Gravity is the main force that governs motion throughout the universe. Normal gravity experienced on Earth is referred to as one G. Microgravity is a term used to describe various states of gravity much less than the normal gravity typically experienced on Earth. Microgravity is experienced during space travel.

"Many people misunderstand why astronauts appear to float in space. A common misconception is that there is no gravity in space. Another common idea is that the gravity from Earth and the Moon each pull on the astronauts from the opposite direction and cancel out. The real reason astronauts appear to float is that they are in a state of free-fall around Earth." [NASA Liftoff to Learning Resource Guide]

NASA uses a variety of different techniques to simulate the conditions of microgravity for use in research and astronaut training. These techniques range from a simple controlled free fall through an elevator shaft to the reduced gravity aircraft that our team will be using.
The Reduced Gravity Education Flight Program utilizes undergraduate research experiments to contribute to NASA's current priority missions.

The reduced gravity aircraft used for flight testing generally flies 30 parabolic maneuvers over the Gulf of Mexico. This parabolic pattern simulates three different types of gravity. During the planes climb to the top of the parabola hypergravity is experienced, estimated at anywhere between 1.8 G to 2 G, for approximately 20 to 22 seconds. Once the plane starts to “nose over” the top of the parabola and descend toward Earth, the plane will experience about 15-25 seconds of microgravity, estimated at 0 G. At the very top and bottom of the parabola, the plane will experience a mix of partial G's between 0 G and 1.8 G which is referred to as “dirty air."