The word astronaut, which is formed from two Greek words, means 'star sailor'.
The word astronaut, formed from two Greek words, means 'star sailor'.
Only flights which reach an altitude of 100 km or more are considered space flights.
Only flights reaching an altitude of 100 km or more are considered space flights.
People who are chosen to become NASA astronauts have to complete a difficult training program which lasts twenty months.
People chosen to become NASA astronauts have to complete a difficult training program lasting twenty months.
Astronauts who spend long periods in space do exercises which have been designed to keep them strong.
Astronauts spending long periods in space do exercises designed to keep them strong.
Spacecraft which intend to escape from Earth's gravity need to reach a speed of about 40,000 km/h.
Spacecraft intend to escape from Earth's gravity need to reach a speed of about 40,000 km/h.
People who watched the Apollo 13 mission on TV or who listened on the radio were very relieved when the astronauts returned safely.
People watching the Apollo 13 mission on TV or listening on the radio were very relieved when the astronauts returned safely.
James Lovell received the Exceptional Service Medal, which was awarded by NASA.
James Lovell received the Exceptional Service Medal, awarded by NASA.
