A.  Early space missions allowed astronomers to study space in ways not possible using telescopes

      1.  Special motors that do not require air are called rockets.

           a.  Solid-propellant rockets cannot be stopped once they are ignited.

           b.  Liquid-propellant rockets can be reignited after they are shut down.

      2.  A satellite -- an object that revolves around another object in an orbit, or circular path

           a.  In 1957 the former Soviet Union launched first artificial satellite Sputnik I.

           b.  Today thousands of communication, scientific, and weather satellites orbit the Earth.

B.  A space probe gathers and transmits information to Earth

      1.  Voyager 1 and Voyager 2 are Space Technology beyond the solar system.

      2.  Pioneer 10, first probe to travel through an asteroid belt

      3.  Galileo, launched in 1989, studied Jupiter and two of its moons, Europa and Io. 

          a.  Gathered information about Jupiter's composition, temperature, and atmospheric pressure.

          b.  Studies of Europa indicate a possible ocean of water and the possible presence of life.

C.  United States began race for the Moon in 1960s.

      1.  First step in the program to reach the Moon began with Project Mercury.

           a.  In 1961, Alan B. Shepard became first U.S. citizen in space.

           b.  In 1962, John Glen became first U.S. citizen to orbit Earth.

       2.  Second step in the Moon race involved Project Gemini.

           a.  Teams of astronauts met and connected with orbiting spacecraft.

           b.  Effects of space travel on humans studied.

           c.  Unoccupied space probes also studied the Moon during Projects Mercury and Gemini.

       3.  Project Apollo -- final step in U.S. program to reach the Moon.

           a.  On July 20, 1969, Apollo 11 landed on the Moon's surface, and Neil Armstrong and Edwin Aldrin became the first two people to set foot on the Moon.

           b.  Six lunar landings resulted from Project Apollo, which ended in 1972.

           c.  Most space missions now cooperative ventures between countries.