In sci.physics Fred J. McCall wrote:
Rick Jones wrote:

In sci.space.policy Jeff Findley wrote:
They're reasonable if they work. SpaceX is trying to avoid adding
other engines to the Falcon 9 first stage. The stage could hover
and land, for example, if it added Super Draco engines to the first
stage. But, they require different fuel and oxidizer than the first
stage carries. This would mean adding completely different tanks,
plumbing, and etc. for those engines. Also, if Super Dracos were
used, it would be advantageous to deplete the kerosene and then vent
any remaining LOX in the tanks before landing. So, any "leftover"
fuel and oxidizer would be "wasted". In my book, this would not be
a good trade to make.

If one wanted to give the Falcon 9 first stage the ability to hover,
wouldn't the most straightforward way to do that be create a
deeply-throttled Merlin?


Straightforward, perhaps, but it's a very big design change so you
start with having to requalify as if it's a whole new engine.

Yet you were just saying in another thread space stuff doesn't have
bureaucrat bull****.


--
Jim Pennino