8 ms·
Fun fact, the difference is because the Soviet designers chose to guide the rocket by varying the thrust between many small fixed engines. The American designer
by Banthum 9y ago
Fun fact, the difference is because the Soviet designers chose to guide the rocket by varying the thrust between many small fixed engines. The American designers chose to have a few large engines that could turn slightly.
I wonder which method the Falcon Heavy uses.
- mhandley 9y agoAll F9 engines are gimballed. The center engines can gimbal further though, for extra control authority when landing. The many smaller engines approach is useful for re-using boosters. When coming back in to land, the stage is almost empty, so very light compared to when it launched. The problem then is reducing thrust far enough to be able to do a propulsive landing. Even with one F9 engine lit, and it throttled down, there's still too much thrust to hover, so the timing has to be really good to reach zero velocity at zero altitude.
- avar 9y agoWhat's your source for that? I'd have assumed that the reason was the engineering effort required to produce an engine the size of the American F-1, leading to smaller engines, at which point it becomes more natural to steer with variable thrust than with gimballed engines. The Soviets didn't produce anything rivaling the F-1 until the RD-170 in the mid-80s, and that uses 4 thrust chambers instead of 1 as the F-1.