Mr Bojangles wrote:That was a great article. There's a follow-up to it:
The F-1B
Not only did NASA reverse-engineer the engine, one of the companies in the Advanced Booster Competition is using that data to create the F-1's successor, the F-1B. Same beast, modern tech. Fun times.
Honestly? That´s a dead end.
That F1-B thingy is everything but "modern". It´s a joke.
It´s the piss poor performance parallel in rockettech to the ever recurring undead Winchester 73 zombie clones in gun tech. Yawn, good night, America...
Plus it´s prone to be a failure since those scholar-smartasses "optimized" all safety margins away. Moneyquote:
"Because they didn't have the analytical tools we have today for minimizing weight, everything was very robust,..."
Yeah, sure, buddy. What could POSSIBLY go WRONG??
Ok, oldschkoool engineers like me could rant for hours about that.
So let´s better offer some constructive criticism (tm).
How does a really modern engine look like? Well, if you don´t want to burn Trillions of tax money until those students´ smartasses learning curve starts to rise, you could simply buy RD-170s.
Or, which is to be preffered, leave it to the Germans.
So how would we make it? "Smartass Students"(tm) would say, we need 8 Meganewtons per unit.
So my humble little self would utter sth like "O RLY?" then.
Because, let´s have a look at the basics first: Saturn Vs mass was 3000tons (so roughly 600tons per F-1), and it deployed only 43tons to the moon, about 1.4 percent or 1/70.
This is a lousy number.
Why so?
Because the Big V lacked boosters.
According to Tsiolkowskis calculations (i made an excelsheet once to play around with stagemasses and different fuels) there´s more possible. With the right fuels and the right massrelations between the stages up to 2.2% or 1/45.
Also, with todays materials we don´t need 43tons to the moon. Let´s be conservative, and say 35 tons at a rate of 1/50 is sufficient (lot´s of safety margin here).
That makes 1750 tons, or about 60% of Big Vs mass.
And since we have boosters now we split our need of first stage engines into six units (two under each barrel), which have to lift slightly less than 300tons each, compared to Big Vs 600t/each.
Makes roghly 3.3 Meganewton per unit, which really eases work on them.
Ok, what wonderfuel (sic!) do we use? Well, liquid methane and LOX.
Why so?
There are a lot of reasons, but the two most important are specific impulse (30% more than RP-1) and then physical characteristics: Almost same density AND temperature as LOX! No need for two different technologies anymore, same pumps, plumbing, sealings, dimensions whatever in both systems.
Makes it less complex and much much more compact, which again saves construction weight and in iteration overall weight and so on.
Why doesn´t somebody use Liquid Methane yet? Well, that was a political decision by some oil-sponsored white collar cretin in Washington, DC...
And the russians? Well, that´s more complicated, but it has to do with a lot of personal quirks and jealousy among the shanghaied german engineers and the russian ones at the bginning (after WW2), and later on with a lot of more complications. Or in other words: SNAFU.
...
Ok, now we have our target power output and our fuel, and since we´re Germans and not smartass blockheads, we will make an engine that pretty much will look like a 50% upscaled version of the SSME. Bang.
That means staged combustion, maybe even full-flow staged combustion if that will work at this size, to get the absolute maximum.
The F1B-dud OTOH would rely on a simple exhaust gas generator design, giving away ANOTHER 15% of specific thrust... (insert rolleyes here
)
Very probably these engines would be reusable, coming back from the 1st- and boosterstages via parachute and airbags. 10 or 20 launches per unit should drastically reduce cost.
Oh, and BTW, 300tons of thrust is a smart number, which can be arranged/combined into a lot of useful rockets for all purposes, from heavyweight LEO via GEO to planet missions. I can elaborate further on that once i find my papers and that exceltool.
...
Ok, but enough german brilli^H^H^H^arrogance for now, i´m pretty sure you all have questions?