The biggest problem is getting into orbit. https://api.media.ccc.de/v/31c3_-_6180_-_en_-_saal_2_-_201412271830_-_rocket_science_how_hard_can_it_be_-_david_madl

The biggest problem is getting into orbit. https://api.media.ccc.de/v/31c3_-_6180_-_en_-_saal_2_-_201412271830_-_rocket_science_how_hard_can_it_be_-_david_madlener https://api.media.ccc.de/v/31c3_-_6180_-_en_-_saal_2_-_20141... Around 19'th minute. Then again, Mars is far so it would take some time to get there. Then again again, most of the ships wouldn't have to have people aboard. Edit: It helps that Mars has an atmosphere of sorts.