Which are the spacecrafts which have been launched to Mars successful beyond the Hohmann window?

 Historically, almost no spacecraft have been successfully launched to Mars outside the optimal 26-month Earth-Mars transfer window (often referred to as a Hohmann or conjunction-class transfer). Because launching outside this window requires a massive amount of extra propellant, space agencies traditionally choose to keep a delayed spacecraft on Earth for two years to wait for the next alignment rather than attempting a high-energy launch.

However, there is a notable recent exception: NASA's twin ESCAPADE (Escape and Plasma Acceleration and Dynamics Explorers) probes.

Because of launch vehicle delays, ESCAPADE became a rare example of a Mars mission adopting a highly unconventional trajectory to overcome a missed optimal window:

• The Missed Window: ESCAPADE was originally scheduled to launch during the standard Mars window in October 2024, but delays with Blue Origin's New Glenn rocket forced it to miss that alignment.
  
  
• The Out-of-Window Launch: Rather than waiting a full 26 months for the next standard window, the twin probes launched in November 2025 on the second flight of the New Glenn rocket.
  
  
• The Alternative Trajectory: Mission planners sent the spacecraft on a looping, "bean-shaped" path around the Sun.
  
  
• Earth Flyby: To gain the necessary momentum to reach Mars, the two spacecraft flew back past Earth in early November 2026, executing engine burns as they passed through the long tail of Earth's magnetic field.
  
  
• Arrival: Following a few minor course corrections, the twin probes are planned to arrive at Mars in September 2027.
  
  

While theoretical non-Hohmann trajectories (like "opposition-class" missions that use Venus gravity assists) are heavily studied for future crewed Mars missions to shorten travel times, robotic orbiters and rovers rely almost exclusively on the standard 26-month window to maximize their scientific payload capacity.