PPT Slide
Celestial Mechanics: Orbits
Interplanetary Spaceflight
How long will such a journey take?
From the figure, the major axis of the spacecraft’s orbit is
Therfore, the semimajor axis, a, is
The Period of such an orbit is given by:
This is the period of an object in a complete elliptical orbit, with semimajor axis 1.25 AU.
It will, therefore, take half of that time, or 0.7 years (about 8.5 months) for a spacecraft to reach Mars.