Page 286 - Inventions - A Visual Encyclopedia (DK - Smithsonian)

Steering
microjets Robotic probes
Solar
cells

Human exploration of space has so far been limited
to Earth orbit, but space agencies have sent dozens

of automated space probes to explore planets, moons,
comets, and asteroids. Flyby missions offer a brief glimpse

of these objects, orbiters carry out more detailed surveys,
and landers and rovers touch down on the surface to
Camera
SPACE window measure conditions and analyze rocks.

Communications
antennae
THE VENERA MISSIONS
LUNA 3 Venus is the nearest planet to Earth,

Our closest neighbor in space, the moon but it proved a huge challenge to
was an obvious target for early exploration. space probes. Several American and
The first successful probe, the Russian-built Russian probes made fleeting flybys
Luna 3, flew past in October 1959 and sent or entered orbit, but early Russian
back the first pictures of the far side of the landers were destroyed in Venus’s
moon, which permanently faces away from hostile atmosphere. In 1975, Russia’s
Earth. Throughout the 1960s, both the US heavily armored Venera 9 finally
and Russia sent a variety of orbiters and sent back the first picture of the
landers to investigate further. volcanic landscape.
Illustration of
Venera 9 on Venus
Dish antenna for
communicating
VOYAGER GRAVITY ASSIST with Earth

Even at high speeds, reaching the distant outer planets takes
years. Fortunately, NASA engineers discovered a way of
shortening journey times by using the gravity of other planets
as a “slingshot” in a maneuver known as gravity assist. This
enabled them to send two Voyager space probes on a tour of Camera
platform
the outer solar system in the 1970s and 1980s.

Voyager 1 Voyager 2 Arrival at
launched, launched, Neptune, Model of the
September August 1977 August 1989 Voyager 1
1977 space probe
Radioisotope
Thermal Generator

POWER WITHOUT THE SUN
Voyager 2’s
flight path Probes in the inner solar system can use solar panels to
make electricity, but missions venturing any further out from
the sun than Mars need an alternative power supply. To
Voyager 1’s
Arrival solve the problem, NASA developed Radioisotope Thermal
at Jupiter, flight path
July 1979 Arrival Arrival Generators (RTGs). These nuclear power supplies can
at Saturn, at Uranus, produce electricity by harnessing the gentle heat emitted by
August 1981 January 1986
small amounts of radioactive plutonium.
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