For this reason, Gaetano Crocco developed the concept of a Nonstop-Round-Trip to Mars, which would have had a far lower energy requirement, as the rocket engines of the craft would only have to accelerate it in a single maneuver to attain the necessary velocity to reach Mars. During the passing of the spacecraft, onboard crew would have performed analysis of the martian surface. Even this trajectory would have amounted to a flight time of a little over one year, if the spacecraft were not accelerated in another orbital maneuver.