Revise GCSE Physics


Question:Why are unmanned space probes sent into space?

Space probes are spacecraft that can visit other planets without the need for astronauts.

Space probes use radio signals to send back pictures and information, about things such as the temperature, magnetic field strength and radiation levels, the gravitational field strength, the composition of any atmosphere.

In 2004 several unmanned missions landed robot vehicles on Mars.

Unmanned space probes do not need to carry food, water or oxygen. They can withstand conditions that would be lethal to astronauts. Unmanned space probes are much easier and cheaper to launch into space, which is always an advantage, since the public is usually paying for the mission.

To send a man into space the spacecraft must carry enough air and food and water to support the man, and have extra energy supplies to keep the spacecraft at room temperature and operate all the other life support systems. All these extra supplies require extra fuel just to get into space which makes it much more difficult. Unmanned space probes can therefore be much smaller and lighter and are easier and cheaper to launch.