Fun Fact: Spacecraft to Mars

It is estimated it would take about two years and eight months for a spacecraft to leave Earth for Mars, undergo a "waiting period" there, then return to Earth.

Mars is at its closest position to Earth only about every 2 years, so a craft reaching Mars must wait out its orbit around the sun before the craft can attempt to fly back to Earth.

Sources: www.space.com, www.britannica.com, earthsky.org