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Comment by ash | Hacker News Reader

It's interesting to compare this with DC-X "Swan Dive" test in 1995:

http://www.youtube.com/watch?v=wv9n9Casp1o

What makes the DC-X so freaking amazing to me is compare the sensors and computers you had available in 1995 to ones you have available today.

It is a great illustration of the 'ecosystem effect' where adjacent technology advances move the entire frontier of a technology forward.

That's a mighty impressive video, but 1995 was pretty good computing power wise.

What blows me away is some of the stuff they did in the 60's, including the moonshots.

A coworker of mine's dad worked on the XC-142 tiltrotor in the early 60's, which has some wild control-mixing between two completely disparate modes of flight. So for example, differential prop pitch is yaw in conventional mode, but roll in "helicopter" mode, and the two modes could be mixed between.

The V-22 Osprey does this with digital computers. The XC-142 did it with analog mechanical computers.

EDIT: One thing about the XC-142 and other tiltrotors, was that they could operate like a normal aircraft but they had ridiculous amounts of power for their weight to enable lifting in vertical mode, which made them "take off like a jackrabbit" in conventional mode. So much so, a couple of pilots tried to beat the F-4 Phantom's zoom climb record in one! http://en.wikipedia.org/wiki/Canadair_CL-84#Testing

the DC-X was also designed to be bottom-heavy, which helps, a lot. Certainly, once the falcon has deployed its payload, it's got a better balance situation than before, but the geometry is very different from the DC-X.

> bottom-heavy, which helps, a lot

I don't know enough about rocketry to know if you're correct. But if you are just saying this and you're not sure, please look at the Pendulum Rocket Fallacy: http://en.wikipedia.org/wiki/Pendulum_rocket_fallacy

well, I learned something today. I just remember learning in high school that the center of force is below the center of mass, so that vector determines the direction of travel, and that always posed a challenge.

DC-X used a F-15 gyro and flight computer.

Let us not forget that it doesn't always work:

http://www.youtube.com/watch?v=JzXcTFfV3Ls

(DC-X crash at 2:10)

Not nearly as impressive.

Not as impressive? Come on. Like we were all doing things like this on our backyards in 1995.

Given historical context this is as much as impressive as what SpaceX are doing right now.

Oops...I meant SpaceX is not nearly as impressive as what they achieved in 1995. Thing can go laterally!

Laterally, and profitably, that is a distinction.

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