Mass of Shuttle and Floating Objects ```Name: Arnol Status: student Age: N/A Location: N/A Country: N/A Date: N/A ``` Question: Does an object, say a baseball, floating inside the Space Shuttle, add weight to the shuttle? Even if it is floating and not touching anything? Replies: Hi Arnol, All objects have mass; the measure of how much "stuff" is in the item. We measure weight as how hard gravity is pulling on this "stuff" All matter going up on the shuttle adds weight because of the mass. This "weight" must be overcome by the rocket's engine in order to propel it into space. Once in space, because of the orbit of the shuttle, we say objects are "weightless". The shuttle is actually in free fall around the Earth, its trajectory happens to match the curvature of the Earth. We call this an orbit. Because the shuttle is in free-fall it experiences "weightlessness". Not exactly true weightlessness but what we call microgravity. Do not confuse this with mass-less. If you bumped into that weightless baseball hard enough or any other floating object for that matter, you could get a bruise. All objects in space still obey the laws of physics. If a big enough weightless object was floating towards you, say you were on a space walk and had to repair a damaged satellite, you could be severely damaged if you got between it and another heavy object. Momentum still rules. Astronauts must match speed and orbit trajectory with any floating objects they are repairing. However, you are still travelling at 17,000 mph or so. It is kind of like trying to work on a bus from another bus matching speeds of 60mph. It seems as if both busses are still and the work can be done, but it is still mighty risky. I hope this answers your question, Martha Croll Click here to return to the Physics Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs