How can we combat the challenge of travelling large distances between objects in space

Using a gravitational slingshot/catapult Manoeuvre the travelling object to a planet or large asteroid so that it accelerates towards it but ultimately misses it. As it heads towards the planet or asteroid, the object increases its velocity and flies past at a greater velocity than before OR Ion drive engines are designed to manoeuvre the ship or satellite using small amounts of fuel Ions are ejected from the satellite at a very high velocity and this provides a small but constant thrust to increase the speed of the spacecraft