List the three great pioneers of rocket science and their contributions.

Here are the three great pioneers of rocket science and some of their contributions:
1. Konstantin Tsiolkovsky - a Russian teacher who realized that liquid fuel instead of solid fuel is needed for rockets to fly outside of Earth's gravity
2. Robert Goddard - an American scientist who created a new system for rockets that cooled that gases that were leaving them which improved the way rockets work significantly
3. Hermann Oberth - a German scientist who created the rocket V-2 which was used in the WWII as a missile bomb

Mass is the amount of matter in an object.  weight is the measurement of the pull of gravity on an object.  say for example, you travel to the moon which has a different gravitational field compared to the gravitational field of earth. (gravitational fields: earth = 1, moon = 0.165)  now when you are on the moon, the pull of gravity on you is different than on the earth. and as weight is the measurement of the pull of gravity on an object, that means yes, your weight can and will change on the moon.  however, on the moon, on earth or even on jupiter, the amount of mass inside of you remains the same. meaning your physical mass remains constant.  in conclusion it is possible for your weight to change as your mass remains constant.