In a message dated 95-10-26 14:45:11 EDT, Jeff Hunt wrote: >While we are talking about the shuttle, why are they called microgravity >experients; why not zero gravity experiments? Two reasons. First; gravity is nearly as strong at shuttle altitudes as it is at the surface. Second; being in free fall, gravity is nearly nutralized, but drag and internal movement, (mostly astronaut's motions,) cause "g" forces at about 10 to the minus 6, (or less.) One of the instruments on STS-73 is the three dimentional accellerometer, (sp?) It's especially usefull in crystal experiments, where any vibration causes disruption in their formation. It records micro gees in three dimentions.