Please take a bit more care with your question. Read it again. Does it make sense?
normally they are unmanned but sometimes they do have people sent up
A space probe is an unmanned spacecraft sent into space.
Unmanned space probes have been sent to various destinations in our solar system, including Mars, Venus, Mercury, Jupiter, Saturn, Uranus, Neptune, and Pluto. They have also traveled beyond our solar system to study interstellar space.
The Pioneer space probes are a series of unmanned space missions sent out by the United States for the purpose of planetary exploration.
An unmanned space probe is a spacecraft that is sent into space to explore planets, moons, asteroids, or other celestial bodies without a crew on board. These probes are usually controlled remotely from Earth for data collection and scientific research purposes.
NASA has sent several unmanned space probes to Saturn, but no manned missions.
An unmanned space flight refers to a mission where a spacecraft is sent into space without humans on board. These missions are typically used for exploration, research, and technology testing purposes. Unmanned space flights are often more cost-effective and can reach places that may be too dangerous for humans.
most of the time, a space shuttle is sent unmanned to space with the satellite on the top of the shuttle. Then they send the sattelite further into space for good precision on the Earth, or other planets.
Unmanned - Space probes are a form of robotic spacecraft.
A space probe is an unmanned device that is sent into space for purposes of exploration. The space shuttle is a manned vehicle meant for research and delivering supplies, equipment, and people into low-Earth orbit.
Yes, Voyager II has. (Voyager II is an unmanned space probe).
The most obvious answer to your question is the fact that people have to return to earth, while an unmanned craft can stay in space infinitely. Manned spacecraft require things like oxygen, water, food and communications equipment, none of which are required by an unmanned spacecraft. That means unmanned spacecrafts can be sent into space for a fraction of the cost of a manned spacecraft. So basically, it's much cheaper and safer to send unmanned spacecrafts to explore the universe.