Earth and Mars align favorably only every 26 months . This alignment, known as "opposition," minimizes the fuel needed for the roughly 300-million-mile trip.
The heavier the payload (rovers, habitats, or fuel), the more powerful the rocket must be to escape Earth's gravity.
Mapping the surface minerals and understanding the planet's internal structure.
Mars is a hostile environment that dictates how equipment and habitats are designed: Mars - NASA Science
Before any rocket launches, mission planners must define clear goals. Common objectives for Mars Exploration include:
Determining if Mars ever supported microbial life.
Getting to Mars requires overcoming massive gravitational and orbital hurdles: