Has any spacecraft ever left the Solar System?
Pioneer 10 is the first man-made object to leave the Solar System. This probe was launched towards Jupiter in 1972 and by 1983 it had reached deep space. Pioneer 10 carried messages about life on Earth to be read by any extraterrestrial travellers who might meet the probe.
What is a space station?
Space stations allow the crew to work in space for long periods in conditions of zero gravity. While conditions in space capsules and the space shuttle are cramped, space stations are more suitable for longer stays in space. Rockets or the space shuttle bring supplies of air and food to the space station, and often a new crew. Space stations are usually made up of several modules that are sent into orbit, one at a time, and assembled in space. Some space stations, such as the Russian Mir, stayed up for many years, and their crews remained in space for months at a time.
How do you breathe in space?
You cannot breathe in the vacuum of space because there is no air. Oxygen is the gas we need to stay alive, and it forms an important part of the air we breathe. All space missions have to carry their own air supply. Pure oxygen was used on the earliest space flights, but after a tragic fire it was realized that pure oxygen was too dangerous. Spacecraft and space stations now carry supplies of air instead. When astronauts go on a ‘space walk’ they wear a space suit that provides them with air at the correct pressure, while still allowing them to move freely.
How far do space probes travel?
Space probes are small packages of instruments that are launched from the Earth to explore planets. They may also travel deeper into space. Probes do not have their own rocket power, apart from tiny thrusters for steering. Probes have landed small instrument capsules on Mars and Venus; these sent back pictures and information. Some probes use the gravity of other planets to extend their voyage. They pass close by a planet, using its gravity to swing around it and be hurled off towards another planet. Using this technique, the Voyager 2 probe was able to visit Jupiter, Saturn, Uranus and Neptune.