Musk says that methane fuel has performance, cost and storage advantages over alternatives and could even be extracted from the Martian atmosphere for use in landing and ascent stages.
Although methane is known to be a better fuel for reusable engine operations in not having significant coking (carbon deposit) problems that kerosene has, Musk noted that this was not a main driver for the choice.
“The energy cost of methane is the lowest and it has a slight Isp (specific impulse) advantage over kerosene,” said Musk, adding that “it does not have the pain-in-the-ass factor that hydrogen has”. Hydrogen, another commonly used fuel, has storage and handling difficulties and the problem of hydrogen embrittlement.
Theoretically "a bunch of smaller cylinders" could be more efficient. Reason for that is a fuel cross feed. So whole rocket is powered by fuel from two cores, then those are detached. Then next two cores are feeding fuel to central core and then detached. Essentially you are getting multistage rocket that do not drag extra mass higher and higher.Interesting idea, but surely a single large cylinder has a much higher volume to mass ratio then a bunch of smaller cylinders? If you're trying to reduce cost per pound surely that's a factor? Also if you're trying to bring these things back to Earth and land them, it's going to be easier with one big rocket rather than seven small ones...
It is much easier to land one core and one second stage than it is to land 6 boosters, and a core and a second stage.
I had an idea. Want to get peoples' opinions on feasibility of the idea.
Complex plumbing was needed to feed fuel and oxidizer into the clustered arrangement of rocket engines. This proved to be extremely fragile, and was a major factor in the design's launch failures. Furthermore, the N1's Baikonur launch complex could not be reached by heavy barge. To allow transport by rail, all the stages had to be broken down and re-assembled. The engines for Block A were only test fired individually and the entire cluster of 30 engines was never static test fired as a unit. Sergei Khrushchev stated that only two out of every batch of six engines were tested.[SUP][/SUP] As a result, the complex and destructive vibrational modes (which ripped apart propellant lines and turbines) as well as exhaust plume and fluid dynamic problems (causing vehicle roll, vacuum cavitation, and other problems) in Block A were not discovered and worked out before flight.[SUP][/SUP] Blocks B and V were static test fired as complete units.
Each booster stage would presumably have all the engines it needs -- just like the Falcon 9 uses 3 of its 9 engines for a braking/reversing burn up high, then a single engine to renter the thick atmosphere and again to finally land. It certainly requires more propellant though.Wouldn't it be super much more expensive? If they make the asparagus-config, trying to land all booster-stages would require extra engines on all the stages. More engines=higher cost? Make your arguments why not.
Wouldn't it be super much more expensive? If they make the asparagus-config, trying to land all booster-stages would require extra engines on all the stages. More engines=higher cost? Make your arguments why not.