In article , says...

On 7/19/2019 9:19 AM, Niklas Holsti wrote:

They might even use propulsive landing for cargo flights.


If that was the plan before replacing the check valve(s) with burst
disks, I wonder if that remains the plan?

It wasn't. NASA has prohibited SpaceX from performing Dragon 2
propulsive landing testing on returning ISS cargo flights. NASA does
not want the added risk for any of its returning cargo. This is why
SpaceX dropped development of propulsive landing for Dragon 2. This
decision happened quite some time ago.

If so it would imply that they (SpaceX) intended to fly all the way down
with pressurized engines all along anyway, so its no big deal either
way. Otherwise it would require some re-thinking.

As with an abort, during a propulsive landing the tanks would only have
been pressurized as part of the Super Draco engine firing sequence, so
they would have been pressurized a fraction of a second before firing
the Super Draco engines. Also, if it performed an abort, it would
necessarily use parachutes for the splashdown. There was never enough
propellant to perform an abort *and* a propulsive landing. It was
always either/or.

The genius of propulsive landing was that on a nominal mission (i.e. no
launch abort), you could use the abort system's engines and propellant
to perform the propulsive landing. For comparison, Starliner's abort
system is in its service module, so it will always be destroyed after a
nominal mission, because the service module burns up on reentry.

Jeff

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