Why NASA Can Only Launch to Mars Every 2 Years

Mars is always up there, so why can we only launch a mission there once every 26 months, and why does the trip take the better part of a year? On October 19, 2026, Japan's MMX mission is scheduled to leave for Mars. If it misses its window, the next chance comes at the end of 2028. In this video: why you can't fly to Mars in a straight line, the Hohmann transfer (the cheapest road to Mars), why you have to aim where Mars will be, the 26-month launch window, what happens when a mission misses it, why astronauts would have to wait 15 months on Mars before coming home, the two weeks every 26 months when Mars goes silent, and which missions are using the 2026 and 2028 windows. 0:00 Intro 0:35 Why not a straight line? 1:25 The cheapest road to Mars 2:14 Hitting a moving target 3:01 The 26-month clock 4:13 Missing the window 4:51 Getting home 5:34 Can we go faster? 6:21 Two weeks of silence 6:54 The next window 7:40 The solar system's timetable Orbits are shown as circles for clarity; transfer orbits are computed with Kepler's laws. #mars #space #spaceexploration