SpaceX is not going to first enter Mars orbit, looks like they're landing the whole craft on the surface. For example, Mars Science Laboratory did the same, an

SpaceX is not going to first enter Mars orbit, looks like they're landing the whole craft on the surface. For example, Mars Science Laboratory did the same, and it didn't need to spend fuel trying to enter orbit. http://mars.nasa.gov/msl/mission/timeline/approach/ http://mars.nasa.gov/msl/mission/timeline/approach/ The closing velocity of spacecraft and Mars is nowhere near 25 km/s. As another example, Apollo did a direct entry to Earth as well. Even when entering orbit, you can sometimes use aerobraking or aerocapture, though it's either limited in delta vee or dangerous if you go lower.