The History of Space Exploration on a Single Space Map | IELTS, ESP, EAP and CALL | Scoop.it
From www.sci-techuniverse.com - July 30, 2018 3:47 AM
Humans have dreamed about spaceflights forever but only in the second half of the 20th century were developed rockets that were powerful enough to overcome the force of gravity to reach orbital velocities that could open space to human exploration.