# Are there any free return trajectories for a manned Mars flyby mission between 2018 and 2024?

I am looking for a mission profile including the delta-v for burns for an interplanetary mission to Mars. I have been unable to find any free return trajectories between 2018 and 2024, are there any?

• Scroll down to my answer to this question and you will find a link to a paper discussing possible free-return trajectories. – Brian Lynch Jan 22 '16 at 1:45
• Not sure why I didn't just link to the paper directly... here is a link. – Brian Lynch Jan 22 '16 at 2:00
• There's a free-return launch opportunity on May 10 2018, and you can find others with NASA's Trajectory Browser tool (link is an example query that will return the trajectory for mentioned date, and see others with Post-Injection ΔV of 0 or close to it - tool allows you to sort results by columns). Technically, Mars cyclers are also free return. – TildalWave Jan 22 '16 at 2:03
• Note that a "free return" isn't really free. You have a much higher departure $\Delta V$ or $C_3$ than a normal Mars transfer trajectory. – Mark Adler Jan 22 '16 at 2:39