Editing Mars Direct (section)

===First launch===

The first flight of the Ares rocket (not to be confused with the similarly named rocket of the now defunct [[Constellation program]]) would take an uncrewed '''Earth Return Vehicle''' to Mars after a 6-month cruise phase, with a supply of hydrogen, a chemical plant and a small [[nuclear reactor]]. Once there, a series of chemical reactions (the [[Sabatier reaction]] coupled with [[electrolysis]]) would be used to combine a small amount of hydrogen (8 tons) carried by the ''Earth Return Vehicle'' with the [[carbon dioxide]] of the Martian atmosphere to create up to 112 tonnes of methane and oxygen. This relatively simple chemical-engineering procedure was used regularly in the 19th and 20th centuries,<ref>{{cite web |url= https://www.nobelprize.org/nobel_prizes/chemistry/laureates/1912/press.html |title= The Nobel Prize in Chemistry 1912 |author= Professor H.G. Söderbaum |date= 2 Sep 2012  |access-date= 2 September 2012}}</ref> and would ensure that only 7% of the return propellant would need to be carried to the surface of Mars.

96 tonnes of methane and oxygen would be needed to send the ''Earth Return Vehicle'' on a trajectory back home at the conclusion of the surface stay; the rest would be available for Mars rovers. The process of generating fuel is expected to require approximately ten months to complete.