Ответ:

  • искусственный: In 1957, the first artificial satellite Sputnik-1 was sent into space.
  • исследовать: Russia continues to explore space and work together with other countries on international space exploration.
  • исследователь: This text doesn't mention the word 'исследователь'.
  • исследование: Russians are very proud of their history of space exploration.
  • на орбите: It was in orbit for three months.
  • национальный герой: He immediately became the most famous astronaut in the world and a national hero.
  • перегрев: Unfortunately, the dog died during the flight from stress and overheating.
  • в целости и сохранности: This text doesn't mention the phrase 'в целости и сохранности'.
  • спутник: In 1957, the first artificial satellite Sputnik-1 was sent into space.