On 18-03-14 00:36 , Jeff Findley wrote:
In article ,
lid says...
...
For small, Grasshopper-like hops, it would be enough to mount just one
of the two (or are there now more than two?) BFS sea-level engines.

Agreed. Two, from this pictu

On the other hand, at
https://www.teslarati.com/elon-musks...bfs-spaceship/,
Musk is quoted as follows (in the section headed "Raptor and rocket
propulsion"):

"If you just have two engines that do everything, the engine complexity
is much higher and, if one fails, you’ve lost half your power. Btw, we
modified the BFS design since IAC to add a third medium area ratio
Raptor engine partly for that reason (lose only 1/3 thrust in engine
out) and allow landings with higher payload mass for the Earth to Earth
transport function."

(Gosh, perhaps the "Earth to Earth transport function" is to be taken
seriously...)

--
Niklas Holsti
Tidorum Ltd
niklas holsti tidorum fi
. @ .