Flight Plan 2020 To minimize propellant, Mars-bound spacecraft take the most efficient path from Earth to Mars. Sitting on the launch pad, the spacecraft already orbits the Sun (with Earth). After it launches, it boosts itself out of an Earthlike orbit into a more elliptical one, with an aphelion that matches up with Mars's orbit. The craft's trajectory follows the outgoing arc of this ellipse (approximate path shown). When it reaches Mars, the spacecraft enters orbit or, if a lander, hits the planet "in a controlled way." MARS July 2020 VENUS July 2020 MERCURY July 2020 MERCURY February 2021 123,000 EARTH July 2020 km/hr Mars 2020 spacecraft's speed relative to the Sun at launch VENUS February 2021 SUN 64,000 km/hr Mars 2020 spacecraft's speed relative to Mars at launch EARTH February 2021 2013 (F) MOM Mangalyaan 2007 (F) Phoenix Mars 2011 (F) MSL Curiosity 2013 (F) MAVEN 2016 (F) Trace Gas Orbiter 2018 (ID) Insight 2020 (ID) Hope 2020 (ID) ExoMars 2020 (ID) China Mars Mission 2020 (ID) Mars 2020 s k y a n d t e l e s c o p e . c o m * N O V E M B E R 2 0 17 17http://www.skyandtelescope.com