3rd.GRADE

SPACE EXPLORATION – VOYAGERS 1 AND 2


The Voyager 1 and 2 spacecrafts left Earth in 1977 on a five-year mission. Their mission was to reach Jupiter and Saturn and send information back to earth about them. Jupiter and Saturn are the largest planets in the solar system. In 1981, they finished their mission. But, they kept going. Scientists decided to plan a longer trip for them: they would travel even further until they reached Uranus and Neptune.

Voyagers 1 and 2 are very efficient. They were built with no moving parts. They use the breakdown, or the decay, of the space element “plutonium” to create fuel. They can each get the equivalent of 30,000 miles per gallon of gasoline! They were made to be able to work in radioactive environments. The “gas giants” – Jupiter, Saturn, Uranus, and Neptune – are very radioactive places.

So far, Voyagers 1 and 2 have sent information back to Earth from farther away than any other spacecraft. Scientists have learned about the atmospheres, interiors, and rings of the gas giant stars. They have also learned about the moon of these stars. Scientists think that they will keep getting information from Voyagers 1 and 2 until about 2020. At that time, the power on the Voyagers 1 and 2 will not be strong enough to send information back to Earth.

Answer the following questions:
1) What are Voyagers 1 and 2?
2) What are the largest planets in the solar system?
3) What do the spacecrafts use for fuel?
4) Whatt happened in 1981?
5) Information from Voyager will come...

Choose the correct alternative:
6) A "mission" is a:
   A. job or occupation.
   B. trip or outing.
   C. plan or goal.
   D. moon.

7) Anotther way to say "efficient" is:
   A. productive without wasting much.
   B. radioactive and dangerous.
   C. very informative.
   D. extremely large.

8) What is the best synonym for “decay”?
   A. Fuel
   B. Rings
   C. Breakdown
   D. Environment

9) What does "equivalent" mean?
   A. Something that is of different value
   B. Something of similar value
   C. Something of value
   D. Something that has little or no value

10) Environments are…
   A. parts.
   B. ideas.
   C. giants.
   D. places.