George's Cosmic Treasure Hunt (8 page)

ROBOTIC SPACE TRAVEL

A space probe is a robotic spacecraft that scientists send out on a journey across the Solar System in order to gather more information about our cosmic neighborhood. Robotic space missions aim to answer specific questions such as: “What does the surface of Venus look like?” “Is it windy on Neptune?” “What is Jupiter made of?”

While robotic space missions are much less glamorous than manned spaceflight, they have several big advantages:

• Robots can travel for great distances, going much farther and faster than any astronaut. Like manned missions, they need a source of power: Most use solar arrays that convert sunlight to energy, but others traveling long distances away from the Sun take their own onboard generator. However, robotic spacecraft need far less power than a manned mission, as they don't need to maintain a comfortable living environment on their journey.
  
• Robots don't need supplies of food or water, and they don't need oxygen to breathe, making them much smaller and lighter than a manned spacecraft.
  
• Robots don't get bored or homesick or fall ill on their journey.
  
• If something goes wrong with a robotic mission, no lives are lost in space.
  
• Space probes cost far less than manned spaceflights, and robots don't want to come home when their mission ends.
  

Space probes have opened up the wonders of the Solar System to us, sending back data that has allowed scientists to far better understand how the Solar System was formed and what conditions are like on other planets. While human beings have, to date, traveled only as far as the Moon—a journey averaging 234,000 miles (376,000 kilometers)—space probes have covered billions of miles and shown us extraordinary and detailed images of the far reaches of the Solar System.

In fact, almost thirty space probes reached the Moon before mankind did! Robotic spacecraft have now been sent to all the other planets in our Solar System, they have caught the dust from a comet's tail, landed on Mars and Venus, and traveled out beyond Pluto. Some space probes have even taken information about our planet and the human race with them. Probes
Pioneer 10
and
11
carry engraved plaques with the image of a man and a woman on them and also a map, showing where the probe came from. As the
Pioneer
s journey onward into deep space, they may one day encounter an alien civilization!

 

The
Voyager
probes took photographs of cities, landscapes, and people on Earth with them, as well as a recorded greeting in many different Earth languages. In the incredibly unlikely event of these probes being picked up by another civilization, these greetings assure any aliens who manage to decode them that we are a peaceful planet and we wish any other beings in our Universe well.

 

There are different types of space probes, and the type used for a particular mission will depend on the question that the probe is attempting to answer. Some probes fly by planets and take pictures for us, passing by several planets on their long journeys. Others orbit a specific planet to gain more information about it and its moons. Another type of probe is designed to land and send back data from the surface of another world. Some of these are rovers, others remain fixed wherever they land.

The first rover,
Lunokhod 1
, was part of a Russian probe,
Luna 17,
which landed on the Moon in 1970.
Lunokhod 1
was a robotic vehicle that could be steered from Earth, in much the same way as a remote control car.