In 1969, when Mike Massimino was seven years old, he dreamt of being an astronaut just like Neil Armstrong, who had just made his historic moon landing. Before the age of 33, Massimino got rejected by NASA three times until he finally reached his goal and learned an important lesson on patience and persistence.
"The most important thing is to never give up. As long as you keep trying, there is always a chance," Massimino tells CNBC Make It. Massimino went on to travel on two space missions, of which the second helped him become the first person to ever tweet from space on May 12, 2009.
