Speculation about Dragon 3

[Excession]

The F9R upper stage reentry concept implies that SpaceX has a solution for reentering and propulsively landing cylindrical vehicles from earth orbit. If they can do that, then why not make "Dragon 3" a cylindrical pressure vessel with aft-mounted propulsion? Simple to manufacture, efficient lightweight structure, and relatively low ballistic coefficients at high angles of attack. It would be characteristic of SpaceX to integrate the upper stage and design its propellant system to also drive RCS thrusters.

Remember, Elon said that the exciting thing about Raptor isn't the engine, it's the spaceship it's attached to...

So you're thinking of something with a layout similar to the old t/Space CEV concept, but on a much larger scale?

[AncientU]

The F9R upper stage reentry concept implies that SpaceX has a solution for reentering and propulsively landing cylindrical vehicles from earth orbit. If they can do that, then why not make "Dragon 3" a cylindrical pressure vessel with aft-mounted propulsion? Simple to manufacture, efficient lightweight structure, and relatively low ballistic coefficients at high angles of attack. It would be characteristic of SpaceX to integrate the upper stage and design its propellant system to also drive RCS thrusters.

Remember, Elon said that the exciting thing about Raptor isn't the engine, it's the spaceship it's attached to...

So you're thinking of something with a layout similar to the old t/Space CEV concept, but on a much larger scale?

Yes, much larger.  Today's capsules have 10-20ish cubic meter volumes.  The Falcon payload fairing has 200m^3 or so.  If half of that was pressurized volume, and the cross section on reentry was the side of the cylinder (maybe flattened somewhat), then the functionality could expand way beyond the limitations of a capsule.  MCT thread is on same topic, but much larger scale -- I think this scale is flyable when FH is ready.  Stretching the cylinder allows volume to grow as heat shield cross section grows without increasing vehicle diameter (unlike a capsule).

Dragon 3 (?) could be the follow-on to Dragon 2 and proof of concept for MCT.