Both the Nova and Saturn rockets, which shared a similar design and could share some parts, were evaluated for the mission. However, it was judged that the Saturn would be easier to get into production, since many of the components were designed to be air-transportable. Nova would require new factories for all the major stages, and there were serious concerns that they could not be completed in time. Saturn required only one new factory, for the largest of the proposed lower stages, and was selected primarily for that reason.