3 ms·
If you do a direct re-entry you don't need to slow down with propulsion at either end. :)
by Gravityloss 10y ago
If you do a direct re-entry you don't need to slow down with propulsion at either end. :)
- dogma1138 10y agoYou aren't going to be doing direct reentry, mars' mean orbital velocity is about 25km/s, your space craft would be traveling at probably 15-20km/s. MOI requires a slow down burn there isn't any way around it, this isn't KSP.
- Gravityloss 10y agoSpaceX 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.