I've been thinking about this interesting comment.
The [special variant of the SpaceX Dragon capsule] Mars One requires will be slightly larger than the current version.
They also mention the supply Dragon will only bring 2500kg to the surface of mars which is much less than the 10mt I've read about regarding the Red Dragon.
Update: The current dragon, even with superdracos, would make a nice crater. The mars lander will be 5 m. wide. The current Dragon is 3.7 m. wide.
While the PicaX heat shield can withstand mars entry temperatures that's not to say the martian atmosphere will drain away enough energy from a standard Dragon to go subsonic before it crashes into the surface. Which is why some suggest adding a hypercone:
Which has a diameter of 30 to 40 meters.This is suppose to slow a vehicle from mach 5 to mach 1 starting from 10 km high and before you become a new crater. If it is required it's a simple addition requiring very little addition mass. The superdracos would then take over for a soft ground landing.
The worry is that "large, flexible structures are notoriously difficult to control." This one shouldn't be, assuming it's required at all, because the forces would be working for you. The other worry is it would cause you to drift from your target landing site. However, no matter how they land, they will always have an issue regarding the size of the landing ellipse. The final stage with thrusters should mitigate that issue perhaps completely. In any case, they will have to establish missions that allow for whatever reality is.
They may want to discard the hypercone before engaging the superdraco landing system. At mach that should be a really quick operation with no possibility of interference with the rest of the landing.
Update: I wonder if it could be inflated by the martian atmosphere itself? Would that allow the outer ring to be rigid enough?
Update: NASA test.
Update: The Mars One lander will be wider than a standard Dragon (for better braking) and not use a hypercone. The placement and angle of the superdracos should allow supersonic retros.
So, assuming 2.5mt and four crew to the martian surface, what will they have besides a space suit? Life support and a mars buggy of course.
The lunar rover was 210 kg with room for two. For mars I've proposed a two part vehicle: a simple tractor (four balloon wheels, batteries and a central fifth wheel hitch.) That pulls a foldable trailer with room for six in space suits and their life support supplies. The wheels of the trailer are far back putting most of the weight on a simple pole bar hitch. The trailer has a simple eye hitch that fits over the pole with a cap or pin to keep it in place.
Let's assume this tractor and trailer together has a mass of 500 kg (including solar panels that can be laid out on stopping and a small methane engine to extend the battery range) which allows a 500 kg allotment per crew. Each colonist in suit should mass about 150 to 200 kg (about 167 lbs. on mars.) So each colonist will have about a months supplies to reach a pre-established base which they should be withing 20 to 40 km. Their landing ellipse should be about 10 km., but much less if using a landing beacon (the advantage of a propulsive landing.)
Update: Arizona CJ provides this PDF.
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