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> orbital transfer times with orbital phases—conventions that do not apply to high-Isp transfers The minimum distance to Mars is 33.9 million miles. The maxim

> orbital transfer times with orbital phases—conventions that do not apply to high-Isp transfers The minimum distance to Mars is 33.9 million miles. The maximum distance to Mars is 225 million miles. You're telling me this engine is so powerful it doesn't matter when you launch you'll always get there in 2 months? Isn't Mars occasionally on the other side of the Sun from us? I'm still failing to grasp this.

JumpCrisscross 2y ago
> minimum distance to Mars is 33.9 million miles. The maximum distance to Mars is 225 million miles Two identical spacecraft could travel the same distance between Earth and Mars and arrive at wildly different times. You’re never taking a linear path; it’s like talking about the diameter of the Earth when comparing two steamboats.
- akira2501 2y ago
  > Two identical spacecraft could travel the same distance between Earth and Mars and arrive at wildly different times. Okay, but this is one spacecraft with a single stated time. So, does that mean it takes the same time regardless of when it was launched in the cycle? Or, does the two month figure only apply to launches at or near the minimum distance?
  - JumpCrisscross 2y ago
    The distance you’re referencing doesn’t matter. You’re never travelling the straight-line path the distance measures.
perihelions 2y ago
- "The minimum distance to Mars is 33.9 million miles" The path we're talking about is not this straight-line distance; it's a much longer trajectory that looks closer to this [0] (probably longer than the one in this particular diagram). Part of the reason is vector velocity addition with Earth's orbital velocity; part of it is that the electric acceleration phase is not instantaneous—rather it's very, very slow. [0] https://www.researchgate.net/figure/Mars-transfer-trajectory-comparison-Orbits-are-to-scale_fig4_357553420 https://www.researchgate.net/figure/Mars-transfer-trajectory...

JumpCrisscross 2y ago

> minimum distance to Mars is 33.9 million miles. The maximum distance to Mars is 225 million miles Two identical spacecraft could travel the same distance between Earth and Mars and arrive at wildly different times. You’re never taking a linear path; it’s like talking about the diameter of the Earth when comparing two steamboats.

akira2501 2y ago
> Two identical spacecraft could travel the same distance between Earth and Mars and arrive at wildly different times. Okay, but this is one spacecraft with a single stated time. So, does that mean it takes the same time regardless of when it was launched in the cycle? Or, does the two month figure only apply to launches at or near the minimum distance?
- JumpCrisscross 2y ago
  The distance you’re referencing doesn’t matter. You’re never travelling the straight-line path the distance measures.

perihelions 2y ago

- "The minimum distance to Mars is 33.9 million miles" The path we're talking about is not this straight-line distance; it's a much longer trajectory that looks closer to this [0] (probably longer than the one in this particular diagram). Part of the reason is vector velocity addition with Earth's orbital velocity; part of it is that the electric acceleration phase is not instantaneous—rather it's very, very slow. [0] https://www.researchgate.net/figure/Mars-transfer-trajectory-comparison-Orbits-are-to-scale_fig4_357553420 https://www.researchgate.net/figure/Mars-transfer-trajectory...