1.) which of these studies is most likely performed by remote observation?
a
a study of earth's oceans by scientists on a research boat
b
a study of the effects of weightlessness on humans in a space station
c
a study of a planet that orbits a star other than the sun
d
a study of the composition of rocks returned from the moon by astronauts
2.) a space shuttle is a reusable spacecraft that launches with the aid of rocket boosters and liquid fuel.
a
true
b
false
3.) scientists use spacecraft to study a variety of objects in space. what benefits do unmanned spacecraft provide to space scientists?
a
instruments can replace analysis by human scientists.
b
instruments require more control over the environment than human space flight does.
c
instruments can be sent places humans cannot go.
d
instruments never commit errors.