Space Puzzle

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Across
  1. 4. soviet space station
  2. 5. newton's book that suggested space travel
  3. 7. Found Uranus
  4. 9. very energetic stellar explosion
  5. 11. space telescope in the X ray region
  6. 12. material to build space elevator that is stronger than kevlar
  7. 13. number of people that set foot on moon
  8. 14. gave the helio-centric model
  9. 15. space telesope in optical range
  10. 16. age of the universe
Down
  1. 1. prize to promote space tourism
  2. 2. place where most comets exist in the solar system
  3. 3. first spacecraft to escape sun's gravity
  4. 6. law that predicts the temperature of the sun
  5. 8. Telstar is the first ------- satellite to be put into orbit
  6. 10. 11.2 m/s