JF Mezei wrote on Sun, 18 Mar 2018
07:29:26 -0400:

On 2018-03-17 09:33, Jeff Findley wrote:

If it is able to propulsively land on Earth, doesn't that more or less
imply ability to land on Mars?

Block 1 might not be able to be refueled, so it couldn't get to Mars in
the first place.


I was asking in terms of design/concept, not about early production
models. Earth has stronger gravity, but also denser atmosphere. So if
you have enough thrust to decererate and land on Earth, would this
imply that you have enough thrust to land on Mars? (less gravity, but
also much less atmosphere to slow you down)


Asked and answered. Let me make it clear for you.

*********************** N O ***********************

Get it now?


In a "Pan Am flight 006 to Mars and back, would the mass of the vehicle
making the drop from space and land to surface be roughly the same ? Or
would landing at one planet require much more fuel?

So far, Falcon 9 stage 1 landed mostly enpty without payload and with
just enough fuel to land. But BFS will land with full payload of people
and 6 months worth of garbage. So onlike Falcon 9 stage 1, BFS is likely
to require a far greater percentage of its engines to land. Right ?
(hence question of whether the number of engines needed is dictated by
the eventual landing with 100 passengers on Earth or on Mars).


The most important difference is that you probably use vacuum engines
to land on Mars, given the lack of atmospheric pressure.


--
"Some people get lost in thought because it's such unfamiliar
territory."
--G. Behn