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The Coriolis effect is a well-known phenomenum, important in meteorology and ocean current forecasting. In addition to location (latitude), it depends on velocity and duration. I assume that commercial aircraft autopilot inertial guidence systems have the ability to compensate for Coriolis, and that even intercontinental missiles are designed with guidance systems that provide Coriolis capability for target accuracy. Was it necessary to provide space shuttles a means to deal with the Coriolis effect during re-entry?

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3 Answers 3

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I am not particularly an expert either, but my understanding is that shuttle flight is a very active process compared to ballistic motion, so any effects the Coriolis effect might have can just as well be considered as additional errors in the trajectory, which is being adjusted. There's an active feedback loop at work: "observe flightpath -> identify desired corrections -> correct and observe."

Contrast this with pure ballistic motion (e.g., a cannonball), where only initial quantities can be manipulated, and you have to account for this if it's significant (i.e., naval artillery charts).

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OK, this isn't really an answer since I honestly don't know what the answer is but I Googled "shuttle autopilot coriolis effect" and the 2nd link was this:

Design of the space shuttle digital autopilot and resulting dynamic environment

"CORIOLIS EFFECT" is one of the key words for the document. It's old and not available digitally but you can request it.

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I don't have any special knowledge about this area, but "Shuttle Entry Guidance", from NASA's Mission Planning and Analysis Division, says: "These equations of motion neglect the Coriolis and centripetal accelerations due to the Earth's rotation because these accelerations are small compared to the aerodynamic acceleration." –  mmc Jul 3 '12 at 2:01
    
Well, there it is. Thanks! –  Alfred Centauri Jul 3 '12 at 2:09
    
Thanks Alfred and mmc. –  Michael Luciuk Jul 3 '12 at 4:59

I am not an expert either, but I think the answer is still simpler than the one that James provided. First of all, the Coriolis effect is only mysterious if you think that your spot on the earth is stationary with respect to say, the sun. Once you acknowledge that a spot on the earth is moving you can take this into account with cannonballs and airplanes alike (they are both trying to hit moving targets). That is, we know that an airplane shouldn't fly from Miami to NY city and shoot for where NY currently is when it leaves Miami, but where it will be in the approximate time it will take to get to the latitude of NY city. For cannonballs we only get to make the choice once, when we shoot it, but for airplanes we can constantly adjust. HOWEVER - if we shoot for where NY city will be in a given time instead of constantly adjusting, we will have a much more efficient flight path that if we constantly adjust to where NY is instantaneously. Thats not to say airplanes don't adjust their flight paths, they can and do, but I would say they use this for instantaneous and evolving flight conditions, rather than something they can easily anticipate - NY city will have 'moved' by the time the flight gets there.

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