TL;DR
Earth and Mars line up for an efficient trip only once every 26 months, so Mars missions have launched when the planets were aligned, and a mission that misses the window sits on the ground until the next one. NASA's twin ESCAPADE probes went a different way. They launched in November 2025, with the planets on opposite sides of the Sun, waited out the gap in a holding orbit in deep space, and are now swinging back past Earth to fire their engines at closest approach and use the planet as a slingshot toward Mars. Spacecraft 1 makes its pass around 5 a.m. EST on Saturday, Nov. 7, and spacecraft 2 around 6 a.m. EST on Monday, Nov. 9. No NASA spacecraft has flown a powered Earth flyby like this before. For future explorers, it means a Mars mission can leave when it is ready rather than when the calendar allows, and these two will arrive in September 2027 to measure how the Sun has been stripping Mars of its air, data NASA says will help design human missions there. Our odds that both probes make it into orbit around Mars: a 92% chance it works, likely by 2027. For the full odds on the twins and on the new route to Mars, and the timeline of what comes next, subscribe.
Below the line, for paid subscribers: The full story: where it stands, how we got here and what's dated next; our labeled speculation on what it adds up to; and every source.