No need to kill, you just have to put on your robe and wizard hat.

Hey, at least the NASA thugs are intercepting ISIS's communications. Although I've never understood why they keep sending them supplies...

In addition, I'm no statistician but doesn't "significant" mean "zero is not within the error bars"? I wonder how many people are going to read "significant' as "large"...

That would be a three-meter pole in France.

I meant a pneumatic device. (And of course servos and a computer instead of hand aiming, since a moving target is involved).

I didn't move the goalposts. I responded to your original claims that "[dumping] the turbine exhaust into the combustion chamber [to] gain additional thrust from it (closed circuit rocket engine)" - which is EXACTLY what the RS-25 from the 1970s does - was allegedly "a unique technology" that "Lockheed Martin engineers" didn't believe was possible. The way your claims were stated, they were simply untrue and ignorant, perhaps aside from the fact that RS-25 indeed got very complex as a result of using this cycle.

The funny thing is that Russians were to a large extent forced to develop the oxygen-rich cycle hydrocarbon (and even hypergolic) engines because they didn't have the one thing that Americans did - efficient hydrogen/oxygen upper-stage engines (such as the RL-10) which removed a lot of the need for this cycle in the first stage (and perhaps even more importantly, the need to build the complex and expensive ground facilities for this propellant, which Russians did once - for Energia - and then swiftly canceled it for cost reasons). And once they had such engines as the RD-253, they simply learned to manage without high energy upper stages. Now whether getting hydrolox-crazy like Americans are even today was a good idea is highly debatable (Delta IV!), but that's how it ended up. Nowadays even the Angara is going to use the one Russian hydrogen engine that made it into an actual non-doomed vehicle (at least non-doomed yet!), the RD-0146 (which, unsurprisingly, is a redesign of RL-10).

Actually, you're the one being a deliberately obtuse asshole here. You asked for staged combustion engines, I gave you an American staged combustion engine. You claimed it was a "test project with no meaningful thrust", I refuted that by showing that it has a very decent 2.3 MN of thrust in practical use. You argued "but it isn't a first stage engine!" and "it's different from Russian engines", even though neither being a first stage engine nor being a ultra-high thrust engine nor being an oxy-rich engine were any part of your original request, which merely asked for a staged combustion engine.

It's difficult to argue with people who randomly move the goalposts, but your deficient knowledge of the history of rocketry isn't my problem. You got what you asked for, and I don't have a crystal ball to see any of your further requirements.

"Low thrust"? 2.3 meganewtons per nozzle is actually in the same ballpark as all the Russian kerolox engines. The RD-191 has 2.1 meganewtons. There hasn't really been a lot of engines that large. I'm not sure why you're being deliberately obtuse, but if this floats your boat, whatever.

As I said, RS-25 existed long before that. You've just widened their surprise from oxygen-rich staged combustion to staged combustion in general (RS-25 runs fuel-rich).

They have thrust vectoring, but the fact that the engine thrust (even throttled down) significantly exceeds the terminal stage mass and you only have one landing attempt probably means that the usable range of terminal trajectories is limited (you can't hover and divert the way that the Grasshopper could), and presumably the premature fin failure led to a situation the terminal guidance couldn't deal with. Additionally, the fins allegedly failed in a non-neutral position - in fact, they were in an extreme position. That's like a ship's rudder getting stuck in a "hard left" position. Even with multiple screws, it's still not a nice situation to be in.

This is a popular legend that actually isn't true, the US had had closed cycle engines before the US engineers saw Russian engines (notably the RS-25). The actual problem was that the Russian-style closed cycle works with a high-pressure, high-temperature oxygen-rich mixture, which is a metallurgical challenge. So it's not closed cycle engines in general but oxygen-rich preburner engines in particular.

You'll just swallow a pill and grow a new kidney.