SOLAR SYSTEM

Detailed explanation-1: -We launch satellites and spacecraft into space by putting them on rockets carrying tons of propellants. The propellants give the rocket enough energy to boost away from Earth’s surface. Because of the pull of Earth’s gravity, largest, heaviest spacecraft need the biggest rockets and the most propellent.

Detailed explanation-2: -Rockets, also called launch vehicles, play an important role in our lives. Rockets deliver satellites to space where they can begin to do their important work.

Detailed explanation-3: -All satellites are launched to space and into their orbit by hitching a ride on a rocket or on the Space Shuttle, where they are placed inside the cargo bay. There are also countries and large corporations that have their own rocket launch facilities, so they can easily send their own satellites into orbit.

Detailed explanation-4: -Most satellites have simple reliable chemical thrusters (often monopropellant rockets) or resistojet rockets for orbital station-keeping and some use momentum wheels for attitude control.

Detailed explanation-5: -Getting directions, watching television, monitoring the weather, conducting scientific research-our lives have been fundamentally changed by thousands of satellites in orbit around Earth.

Detailed explanation-6: -On October 4, 1957, the Soviet Union launched the earth’s first artificial satellite, Sputnik I.