Capsules like Soyuz can't land without an atmosphere. They use aerobraking and parachutes.
You need a big rocket to slow down and land. At which point it's a very different machine.
You need a big rocket to slow down and land. At which point it's a very different machine.
Work in progress..Well along in progress.
And especially interested on what the options for the problem scenarios look like (e.g. burning off too much or not enough velocity).
Not even close. Dragon has something like 450m/s of dv to use. Getting from the surface of Mars to orbit takes 3800. Orbital capture requires around 2000m/s. Without aerobraking, it couldn't enter Mars orbit, let alone land.
> The Dragon-2 has enough power and fuel to land and ascend back to lunar orbit. The Dragon's SuperDraco has higher performance than the Apollo Lunar Module. Apollo LM descent engines has 10,000 lbf thrust, and 3,500 lbf thrust for ascent (the lander part is left behind). The Dragon's SuperDraco has 16,000 lbf thrust. The Dragon also uses computers to control throttle and land (much more fuel efficient). Hence, the Dragon-2 has enough power and fuel to land and ascend back to lunar orbit even if it carries all it's parts during ascent. However, it may need to cut crew from 7 to 3 to loose more weight for fuel.
(Plus, I said "more SpaceX" as in "capsules with powered descent", not "SpaceX's exact current models as already implemented"...)
Estimates are that the Dragon v2 has about 400m/s dV. This is around what it would need for controlled landing or abort. It takes around 1720m/s just to get to the stationary Lunar surface from Lunar orbit; If a Falcon upper stage detaches during the leg of the mission between Earth and Luna, the necessary delta V for the rest of the mission will be around 5080m/s. This is a lot. You would have to build another fairly large vehicle to accomplish this mission - Dragon v2 would be an afterthought.
At the very least, they'd need to consider the dry weight and fuel load to make a fair comparison - maybe they did so offscreen but it's not mentioned anywhere in the post.
Maybe it has been designed to work as a technology platform for deriving a lunar lander. But the Dragon 2 design is just not capable of doing it, not even close.