thanks all...but none of you friends understood my question...
lets give you a clearance about what is across my mind...first i am not from an english country and miss-spelling may occur in my post...i have a basic information about physics and not involved with equations and formulas
second...
a question has made my mind busy...it is told that there is no frictions at space...frictions of air...friction of gravity and etc...none of these does exist in the space (outside the earth)...so we can launch a spacecraft with a primary speed(orbit speed of earth) and equip it with a...