Human beings are so curious. We send people to the Moon. Now want to escape from the solar system. To go to different solar system, we need spacecraft. We can build spacecraft, but the most difficult things for spacecraft to navigate it.
Challenges of Spaceship Navigation
For space navigation we face #four big challenges
The first and foremost problem we faced for sending spacecraft is that its motion. Since the spacecraft is traveling many thousands of kilometers per hour, far from the earth. Again, this earth is rotating and moving around the Sun. So, considering all aspect motion makes difficult problem to navigate the ship.
This is another big problem to send spaceship to space. If Earth were the size of a softball, the International Space Station would be orbiting just above the seams, the Moon would be a marble about 2 meters (7 feet) away, and Mars would be 1.2 to 2.4 kilometers (.75 to 1.5 miles) away. The targets are small and moving.
Deep Space communication using radio telescope.
Generally, for communication we use radio wave.
For communication Probes use radio signal from antenna and send back to ground station.
Another crucial part for deep space communication is gravity. Especially when we send spacecraft to different planetary system the gravity of sun effect enormous ways. Basically, Suns gravity determines the basic trajectory of an interplanetary spacecraft and for deep space mission, a navigator also has to take into account gravitational forces from planets and moons and other forces that might affect the trajectory.
Satellite under gravitational field.
Our interplanetary travel can be explained easily by this following videos.
I hope 
